diff --git a/apps/bff/package.json b/apps/bff/package.json
index 087e1bec..b6daea4f 100644
--- a/apps/bff/package.json
+++ b/apps/bff/package.json
@@ -1,7 +1,7 @@
 {
   "name": "@customer-portal/bff",
   "version": "1.0.0",
-  "type": "module",
+  "type": "commonjs",
   "description": "Backend for Frontend API",
   "author": "",
   "private": true,
diff --git a/apps/bff/src/infra/mappers/user.mapper.ts b/apps/bff/src/infra/mappers/user.mapper.ts
index 9450167a..590ceaf9 100644
--- a/apps/bff/src/infra/mappers/user.mapper.ts
+++ b/apps/bff/src/infra/mappers/user.mapper.ts
@@ -9,10 +9,9 @@
 
 import type { User as PrismaUser } from "@prisma/client";
 import type { UserAuth } from "@customer-portal/domain/customer";
-import { 
-  mapPrismaUserToUserAuth, 
-  type PrismaUserRaw 
-} from "@customer-portal/domain/customer/providers/portal";
+import { Providers as CustomerProviders } from "@customer-portal/domain/customer";
+
+type PrismaUserRaw = Parameters<typeof CustomerProviders.Portal.mapPrismaUserToUserAuth>[0];
 
 /**
  * Maps Prisma User entity to Domain UserAuth type
@@ -40,6 +39,6 @@ export function mapPrismaUserToDomain(user: PrismaUser): UserAuth {
   };
 
   // Use domain provider mapper
-  return mapPrismaUserToUserAuth(prismaUserRaw);
+  return CustomerProviders.Portal.mapPrismaUserToUserAuth(prismaUserRaw);
 }
 
diff --git a/apps/bff/tsconfig.json b/apps/bff/tsconfig.json
index 44837be1..e25246a1 100644
--- a/apps/bff/tsconfig.json
+++ b/apps/bff/tsconfig.json
@@ -1,8 +1,8 @@
 {
   "extends": "../../tsconfig.base.json",
   "compilerOptions": {
-    "module": "Node16",
-    "moduleResolution": "node16",
+    "module": "commonjs",
+    "moduleResolution": "node",
     "lib": ["ES2022"],
     "noEmit": true,
     "baseUrl": ".",
@@ -27,13 +27,14 @@
     "typeRoots": ["./node_modules/@types"],
     "emitDecoratorMetadata": true,
     "experimentalDecorators": true,
-    "strictPropertyInitialization": false
+    "strictPropertyInitialization": false,
+    "esModuleInterop": true,
+    "allowSyntheticDefaultImports": true
   },
   "ts-node": {
     "transpileOnly": true,
-    "esm": true,
     "compilerOptions": {
-      "module": "Node16"
+      "module": "commonjs"
     }
   },
   "include": ["src/**/*", "scripts/**/*", "src/types/**/*"],
diff --git a/packages/domain/auth/index.ts b/packages/domain/auth/index.ts
index d1e5a638..652b1cf8 100644
--- a/packages/domain/auth/index.ts
+++ b/packages/domain/auth/index.ts
@@ -20,7 +20,7 @@ export {
   type AuthErrorCode,
   type TokenTypeValue,
   type GenderValue,
-} from "./contract.js";
+} from "./contract";
 
 export type {
   // Request types
@@ -47,7 +47,7 @@ export type {
   CheckPasswordNeededResponse,
   // Error types
   AuthError,
-} from "./contract.js";
+} from "./contract";
 
 // ============================================================================
 // Schemas (for validation)
@@ -81,4 +81,4 @@ export {
   passwordChangeResultSchema,
   ssoLinkResponseSchema,
   checkPasswordNeededResponseSchema,
-} from "./schema.js";
+} from "./schema";
diff --git a/packages/domain/auth/schema.ts b/packages/domain/auth/schema.ts
index 1e56c91d..70d910cf 100644
--- a/packages/domain/auth/schema.ts
+++ b/packages/domain/auth/schema.ts
@@ -12,8 +12,8 @@
 
 import { z } from "zod";
 
-import { emailSchema, nameSchema, passwordSchema, phoneSchema } from "../common/schema.js";
-import { addressSchema, userSchema } from "../customer/schema.js";
+import { emailSchema, nameSchema, passwordSchema, phoneSchema } from "../common/schema";
+import { addressSchema, userSchema } from "../customer/schema";
 
 // ============================================================================
 // Authentication Request Schemas
diff --git a/packages/domain/billing/index.ts b/packages/domain/billing/index.ts
index dfa60efc..54e9c84a 100644
--- a/packages/domain/billing/index.ts
+++ b/packages/domain/billing/index.ts
@@ -7,11 +7,11 @@
  */
 
 // Constants
-export { INVOICE_STATUS } from "./contract.js";
-export * from "./constants.js";
+export { INVOICE_STATUS } from "./contract";
+export * from "./constants";
 
 // Schemas (includes derived types)
-export * from "./schema.js";
+export * from "./schema";
 
 // Re-export types for convenience
 export type {
@@ -28,7 +28,7 @@ export type {
 } from './schema';
 
 // Provider adapters
-export * as Providers from "./providers/index.js";
+export * as Providers from "./providers/index";
 
 // Re-export provider raw types (request and response)
 export type {
@@ -45,4 +45,4 @@ export type {
   WhmcsCapturePaymentResponse,
   WhmcsCurrency,
   WhmcsCurrenciesResponse,
-} from "./providers/whmcs/raw.types.js";
+} from "./providers/whmcs/raw.types";
diff --git a/packages/domain/billing/providers/index.ts b/packages/domain/billing/providers/index.ts
index f50c5a27..d1a74140 100644
--- a/packages/domain/billing/providers/index.ts
+++ b/packages/domain/billing/providers/index.ts
@@ -2,8 +2,8 @@
  * Billing Domain - Providers
  */
 
-import * as WhmcsMapper from "./whmcs/mapper.js";
-import * as WhmcsRaw from "./whmcs/raw.types.js";
+import * as WhmcsMapper from "./whmcs/mapper";
+import * as WhmcsRaw from "./whmcs/raw.types";
 
 export const Whmcs = {
   ...WhmcsMapper,
@@ -12,5 +12,5 @@ export const Whmcs = {
 };
 
 export { WhmcsMapper, WhmcsRaw };
-export * from "./whmcs/mapper.js";
-export * from "./whmcs/raw.types.js";
+export * from "./whmcs/mapper";
+export * from "./whmcs/raw.types";
diff --git a/packages/domain/billing/providers/whmcs/index.ts b/packages/domain/billing/providers/whmcs/index.ts
index 644fdb12..c95a1ab4 100644
--- a/packages/domain/billing/providers/whmcs/index.ts
+++ b/packages/domain/billing/providers/whmcs/index.ts
@@ -1,2 +1,2 @@
-export * from "./mapper.js";
-export * from "./raw.types.js";
+export * from "./mapper";
+export * from "./raw.types";
diff --git a/packages/domain/billing/providers/whmcs/mapper.ts b/packages/domain/billing/providers/whmcs/mapper.ts
index a8f52a05..2141dc82 100644
--- a/packages/domain/billing/providers/whmcs/mapper.ts
+++ b/packages/domain/billing/providers/whmcs/mapper.ts
@@ -4,14 +4,14 @@
  * Transforms raw WHMCS invoice data into normalized billing domain types.
  */
 
-import type { Invoice, InvoiceItem } from "../../contract.js";
-import { invoiceSchema } from "../../schema.js";
+import type { Invoice, InvoiceItem } from "../../contract";
+import { invoiceSchema } from "../../schema";
 import {
   type WhmcsInvoiceRaw,
   whmcsInvoiceRawSchema,
   type WhmcsInvoiceItemsRaw,
   whmcsInvoiceItemsRawSchema,
-} from "./raw.types.js";
+} from "./raw.types";
 
 export interface TransformInvoiceOptions {
   defaultCurrencyCode?: string;
diff --git a/packages/domain/catalog/index.ts b/packages/domain/catalog/index.ts
index e386ae08..e798d8e9 100644
--- a/packages/domain/catalog/index.ts
+++ b/packages/domain/catalog/index.ts
@@ -7,10 +7,10 @@
  */
 
 // Provider-specific types
-export { type SalesforceProductFieldMap } from "./contract.js";
+export { type SalesforceProductFieldMap } from "./contract";
 
 // Schemas (includes derived types)
-export * from "./schema.js";
+export * from "./schema";
 
 // Re-export types for convenience
 export type {
@@ -29,16 +29,16 @@ export type {
   VpnCatalogProduct,
   // Union type
   CatalogProduct,
-} from './schema.js';
+} from './schema';
 
 // Provider adapters
-export * as Providers from "./providers/index.js";
+export * as Providers from "./providers/index";
 
 // Re-export provider raw types for convenience
-export * from "./providers/salesforce/raw.types.js";
+export * from "./providers/salesforce/raw.types";
 
 // Re-export WHMCS provider types
 export type {
   WhmcsCatalogProduct,
   WhmcsCatalogProductListResponse,
-} from "./providers/whmcs/raw.types.js";
+} from "./providers/whmcs/raw.types";
diff --git a/packages/domain/catalog/providers/index.ts b/packages/domain/catalog/providers/index.ts
index 0de0d0d0..44a1c6fe 100644
--- a/packages/domain/catalog/providers/index.ts
+++ b/packages/domain/catalog/providers/index.ts
@@ -2,9 +2,9 @@
  * Catalog Domain - Providers
  */
 
-import * as SalesforceMapper from "./salesforce/mapper.js";
-import * as SalesforceRaw from "./salesforce/raw.types.js";
-import * as WhmcsRaw from "./whmcs/raw.types.js";
+import * as SalesforceMapper from "./salesforce/mapper";
+import * as SalesforceRaw from "./salesforce/raw.types";
+import * as WhmcsRaw from "./whmcs/raw.types";
 
 export const Salesforce = {
   ...SalesforceMapper,
@@ -17,6 +17,6 @@ export const Whmcs = {
 };
 
 export { SalesforceMapper, SalesforceRaw, WhmcsRaw };
-export * from "./salesforce/mapper.js";
-export * from "./salesforce/raw.types.js";
-export * from "./whmcs/raw.types.js";
+export * from "./salesforce/mapper";
+export * from "./salesforce/raw.types";
+export * from "./whmcs/raw.types";
diff --git a/packages/domain/catalog/providers/salesforce/index.ts b/packages/domain/catalog/providers/salesforce/index.ts
index 644fdb12..c95a1ab4 100644
--- a/packages/domain/catalog/providers/salesforce/index.ts
+++ b/packages/domain/catalog/providers/salesforce/index.ts
@@ -1,2 +1,2 @@
-export * from "./mapper.js";
-export * from "./raw.types.js";
+export * from "./mapper";
+export * from "./raw.types";
diff --git a/packages/domain/catalog/providers/salesforce/mapper.ts b/packages/domain/catalog/providers/salesforce/mapper.ts
index 5102cc0d..9b12b8b1 100644
--- a/packages/domain/catalog/providers/salesforce/mapper.ts
+++ b/packages/domain/catalog/providers/salesforce/mapper.ts
@@ -13,11 +13,11 @@ import type {
   SimCatalogProduct,
   SimActivationFeeCatalogItem,
   VpnCatalogProduct,
-} from "../../contract.js";
+} from "../../contract";
 import type {
   SalesforceProduct2WithPricebookEntries,
   SalesforcePricebookEntryRecord,
-} from "./raw.types.js";
+} from "./raw.types";
 
 // ============================================================================
 // Tier Templates (Hardcoded Product Metadata)
diff --git a/packages/domain/catalog/providers/whmcs/index.ts b/packages/domain/catalog/providers/whmcs/index.ts
index 3f41fad4..f8bb8eb7 100644
--- a/packages/domain/catalog/providers/whmcs/index.ts
+++ b/packages/domain/catalog/providers/whmcs/index.ts
@@ -1,2 +1,2 @@
-export * from "./raw.types.js";
+export * from "./raw.types";
 
diff --git a/packages/domain/common/index.ts b/packages/domain/common/index.ts
index 2bda4f78..bdd94657 100644
--- a/packages/domain/common/index.ts
+++ b/packages/domain/common/index.ts
@@ -4,14 +4,14 @@
  * Shared types and utilities used across all domains.
  */
 
-export * from "./types.js";
-export * from "./schema.js";
-export * from "./validation.js";
+export * from "./types";
+export * from "./schema";
+export * from "./validation";
 
 // Common provider types (generic wrappers used across domains)
-export * as CommonProviders from "./providers/index.js";
+export * as CommonProviders from "./providers/index";
 
 // Re-export provider types for convenience
-export type { WhmcsResponse, WhmcsErrorResponse } from "./providers/whmcs.js";
-export type { SalesforceResponse } from "./providers/salesforce.js";
+export type { WhmcsResponse, WhmcsErrorResponse } from "./providers/whmcs";
+export type { SalesforceResponse } from "./providers/salesforce";
 
diff --git a/packages/domain/common/providers/index.ts b/packages/domain/common/providers/index.ts
index 5d6247fe..66cf0a19 100644
--- a/packages/domain/common/providers/index.ts
+++ b/packages/domain/common/providers/index.ts
@@ -4,5 +4,5 @@
  * Generic provider-specific response structures used across multiple domains.
  */
 
-export * as Whmcs from "./whmcs.js";
-export * as Salesforce from "./salesforce/index.js";
+export * as Whmcs from "./whmcs";
+export * as Salesforce from "./salesforce/index";
diff --git a/packages/domain/common/providers/salesforce/index.ts b/packages/domain/common/providers/salesforce/index.ts
index 3f41fad4..f8bb8eb7 100644
--- a/packages/domain/common/providers/salesforce/index.ts
+++ b/packages/domain/common/providers/salesforce/index.ts
@@ -1,2 +1,2 @@
-export * from "./raw.types.js";
+export * from "./raw.types";
 
diff --git a/packages/domain/customer/index.ts b/packages/domain/customer/index.ts
index 8f5fbbc6..2517e73e 100644
--- a/packages/domain/customer/index.ts
+++ b/packages/domain/customer/index.ts
@@ -15,7 +15,7 @@
 // Constants
 // ============================================================================
 
-export { USER_ROLE, type UserRoleValue } from "./contract.js";
+export { USER_ROLE, type UserRoleValue } from "./contract";
 
 // ============================================================================
 // Domain Types (Clean Names - Public API)
@@ -27,7 +27,7 @@ export type {
   UserRole,       // "USER" | "ADMIN"
   Address,        // Address structure (not "CustomerAddress")
   AddressFormData, // Address form validation
-} from "./schema.js";
+} from "./schema";
 
 // ============================================================================
 // Schemas
@@ -42,7 +42,7 @@ export {
   // Helper functions
   combineToUser,        // Domain helper: UserAuth + WhmcsClient → User
   addressFormToRequest,
-} from "./schema.js";
+} from "./schema";
 
 // ============================================================================
 // Provider Namespace
@@ -56,7 +56,7 @@ export {
  * - Providers.Whmcs.transformWhmcsClientResponse()
  * - Providers.Portal.mapPrismaUserToUserAuth()
  */
-export * as Providers from "./providers/index.js";
+export * as Providers from "./providers/index";
 
 // ============================================================================
 // Provider Raw Response Types (Selective Exports)
@@ -76,7 +76,7 @@ export type {
   WhmcsAddClientResponse,
   WhmcsValidateLoginResponse,
   WhmcsSsoResponse,
-} from "./providers/whmcs/raw.types.js";
+} from "./providers/whmcs/raw.types";
 
 // ============================================================================
 // Provider-Specific Types (For Integrations)
@@ -89,4 +89,4 @@ export type {
 export type {
   SalesforceAccountFieldMap,
   SalesforceAccountRecord,
-} from "./contract.js";
+} from "./contract";
diff --git a/packages/domain/customer/providers/index.ts b/packages/domain/customer/providers/index.ts
index 5f2ba815..9418f559 100644
--- a/packages/domain/customer/providers/index.ts
+++ b/packages/domain/customer/providers/index.ts
@@ -6,5 +6,5 @@
  * - Whmcs: WHMCS API → WhmcsClient
  */
 
-export * as Portal from "./portal/index.js";
-export * as Whmcs from "./whmcs/index.js";
+export * as Portal from "./portal/index";
+export * as Whmcs from "./whmcs/index";
diff --git a/packages/domain/customer/providers/portal/index.ts b/packages/domain/customer/providers/portal/index.ts
index 0187c163..ab0d3e8c 100644
--- a/packages/domain/customer/providers/portal/index.ts
+++ b/packages/domain/customer/providers/portal/index.ts
@@ -4,6 +4,6 @@
  * Handles mapping from Prisma (portal database) to UserAuth domain type
  */
 
-export * from "./mapper.js";
-export * from "./types.js";
+export * from "./mapper";
+export * from "./types";
 
diff --git a/packages/domain/customer/providers/portal/mapper.ts b/packages/domain/customer/providers/portal/mapper.ts
index d55fca00..d7df7193 100644
--- a/packages/domain/customer/providers/portal/mapper.ts
+++ b/packages/domain/customer/providers/portal/mapper.ts
@@ -4,9 +4,9 @@
  * Maps Prisma user data to UserAuth domain type using schema validation
  */
 
-import { userAuthSchema } from "../../schema.js";
-import type { PrismaUserRaw } from "./types.js";
-import type { UserAuth } from "../../schema.js";
+import { userAuthSchema } from "../../schema";
+import type { PrismaUserRaw } from "./types";
+import type { UserAuth } from "../../schema";
 
 /**
  * Maps raw Prisma user data to UserAuth domain type
diff --git a/packages/domain/customer/providers/portal/types.ts b/packages/domain/customer/providers/portal/types.ts
index b60d1ef6..e9266b0e 100644
--- a/packages/domain/customer/providers/portal/types.ts
+++ b/packages/domain/customer/providers/portal/types.ts
@@ -5,7 +5,7 @@
  * Domain doesn't depend on @prisma/client directly.
  */
 
-import type { UserRole } from "../../schema.js";
+import type { UserRole } from "../../schema";
 
 /**
  * Raw Prisma user data from portal database
diff --git a/packages/domain/customer/providers/whmcs/index.ts b/packages/domain/customer/providers/whmcs/index.ts
index aea2abf7..232b5f5c 100644
--- a/packages/domain/customer/providers/whmcs/index.ts
+++ b/packages/domain/customer/providers/whmcs/index.ts
@@ -5,8 +5,8 @@
  * Exports transformation functions and raw API types (request/response).
  */
 
-export * from "./mapper.js";
-export * from "./raw.types.js";
+export * from "./mapper";
+export * from "./raw.types";
 
 // Re-export domain types for provider namespace convenience
-export type { WhmcsClient, EmailPreferences, SubUser, Stats } from "../../schema.js";
+export type { WhmcsClient, EmailPreferences, SubUser, Stats } from "../../schema";
diff --git a/packages/domain/customer/providers/whmcs/mapper.ts b/packages/domain/customer/providers/whmcs/mapper.ts
index 85802a6e..8e7f17a3 100644
--- a/packages/domain/customer/providers/whmcs/mapper.ts
+++ b/packages/domain/customer/providers/whmcs/mapper.ts
@@ -7,14 +7,14 @@
 
 import { z } from "zod";
 
-import type { WhmcsClient, Address } from "../../schema.js";
-import { whmcsClientSchema, addressSchema } from "../../schema.js";
+import type { WhmcsClient, Address } from "../../schema";
+import { whmcsClientSchema, addressSchema } from "../../schema";
 import {
   whmcsClientSchema as whmcsRawClientSchema,
   whmcsClientResponseSchema,
   type WhmcsClient as WhmcsRawClient,
   type WhmcsClientResponse,
-} from "./raw.types.js";
+} from "./raw.types";
 
 /**
  * Parse and validate WHMCS client response
diff --git a/packages/domain/customer/schema.ts b/packages/domain/customer/schema.ts
index 9e2ed205..7ecfd574 100644
--- a/packages/domain/customer/schema.ts
+++ b/packages/domain/customer/schema.ts
@@ -12,7 +12,7 @@
 
 import { z } from "zod";
 
-import { countryCodeSchema } from "../common/schema.js";
+import { countryCodeSchema } from "../common/schema";
 
 // ============================================================================
 // Helper Schemas
diff --git a/packages/domain/dashboard/contract.ts b/packages/domain/dashboard/contract.ts
index 12133407..0d4733c8 100644
--- a/packages/domain/dashboard/contract.ts
+++ b/packages/domain/dashboard/contract.ts
@@ -4,8 +4,8 @@
  * Shared types for dashboard summaries, activity feeds, and related data.
  */
 
-import type { IsoDateTimeString } from "../common/types.js";
-import type { Invoice } from "../billing/contract.js";
+import type { IsoDateTimeString } from "../common/types";
+import type { Invoice } from "../billing/contract";
 
 export type ActivityType =
   | "invoice_created"
diff --git a/packages/domain/dashboard/index.ts b/packages/domain/dashboard/index.ts
index 743f5c36..46ed6e9a 100644
--- a/packages/domain/dashboard/index.ts
+++ b/packages/domain/dashboard/index.ts
@@ -2,4 +2,4 @@
  * Dashboard Domain
  */
 
-export * from "./contract.js";
+export * from "./contract";
diff --git a/packages/domain/index.ts b/packages/domain/index.ts
index f72dd465..c17c44ef 100644
--- a/packages/domain/index.ts
+++ b/packages/domain/index.ts
@@ -4,15 +4,15 @@
  */
 
 // Re-export domain modules
-export * as Billing from "./billing/index.js";
-export * as Subscriptions from "./subscriptions/index.js";
-export * as Payments from "./payments/index.js";
-export * as Sim from "./sim/index.js";
-export * as Orders from "./orders/index.js";
-export * as Catalog from "./catalog/index.js";
-export * as Common from "./common/index.js";
-export * as Toolkit from "./toolkit/index.js";
-export * as Auth from "./auth/index.js";
-export * as Customer from "./customer/index.js";
-export * as Mappings from "./mappings/index.js";
-export * as Dashboard from "./dashboard/index.js";
+export * as Billing from "./billing/index";
+export * as Subscriptions from "./subscriptions/index";
+export * as Payments from "./payments/index";
+export * as Sim from "./sim/index";
+export * as Orders from "./orders/index";
+export * as Catalog from "./catalog/index";
+export * as Common from "./common/index";
+export * as Toolkit from "./toolkit/index";
+export * as Auth from "./auth/index";
+export * as Customer from "./customer/index";
+export * as Mappings from "./mappings/index";
+export * as Dashboard from "./dashboard/index";
diff --git a/packages/domain/mappings/contract.ts b/packages/domain/mappings/contract.ts
index 54cf8089..9bf0b6f1 100644
--- a/packages/domain/mappings/contract.ts
+++ b/packages/domain/mappings/contract.ts
@@ -4,7 +4,7 @@
  * Normalized types for mapping portal users to external systems.
  */
 
-import type { IsoDateTimeString } from "../common/types.js";
+import type { IsoDateTimeString } from "../common/types";
 
 export interface UserIdMapping {
   id: string;
diff --git a/packages/domain/mappings/index.ts b/packages/domain/mappings/index.ts
index 83e253c9..3a6a9624 100644
--- a/packages/domain/mappings/index.ts
+++ b/packages/domain/mappings/index.ts
@@ -2,9 +2,9 @@
  * ID Mapping Domain
  */
 
-export * from "./contract.js";
-export * from "./schema.js";
-export * from "./validation.js";
+export * from "./contract";
+export * from "./schema";
+export * from "./validation";
 
 // Re-export types for convenience
 export type {
@@ -12,5 +12,5 @@ export type {
   MappingStats,
   BulkMappingOperation,
   BulkMappingResult,
-} from "./schema.js";
-export type { MappingValidationResult } from "./contract.js";
+} from "./schema";
+export type { MappingValidationResult } from "./contract";
diff --git a/packages/domain/mappings/schema.ts b/packages/domain/mappings/schema.ts
index 30c6defc..47650c0f 100644
--- a/packages/domain/mappings/schema.ts
+++ b/packages/domain/mappings/schema.ts
@@ -7,7 +7,7 @@ import type {
   CreateMappingRequest,
   UpdateMappingRequest,
   UserIdMapping,
-} from "./contract.js";
+} from "./contract";
 
 export const createMappingRequestSchema: z.ZodType<CreateMappingRequest> = z.object({
   userId: z.string().uuid(),
diff --git a/packages/domain/mappings/validation.ts b/packages/domain/mappings/validation.ts
index 4160091e..52412ebe 100644
--- a/packages/domain/mappings/validation.ts
+++ b/packages/domain/mappings/validation.ts
@@ -10,13 +10,13 @@ import {
   createMappingRequestSchema,
   updateMappingRequestSchema,
   userIdMappingSchema,
-} from "./schema.js";
+} from "./schema";
 import type {
   CreateMappingRequest,
   UpdateMappingRequest,
   UserIdMapping,
   MappingValidationResult,
-} from "./contract.js";
+} from "./contract";
 
 /**
  * Check if a mapping request has optional Salesforce account ID
diff --git a/packages/domain/orders/contract.ts b/packages/domain/orders/contract.ts
index 8450fed8..13d8b0a0 100644
--- a/packages/domain/orders/contract.ts
+++ b/packages/domain/orders/contract.ts
@@ -5,9 +5,9 @@
  * Validated types are derived from schemas (see schema.ts).
  */
 
-import type { SalesforceProductFieldMap } from "../catalog/contract.js";
-import type { SalesforceAccountFieldMap } from "../customer/index.js";
-import type { UserIdMapping } from "../mappings/contract.js";
+import type { SalesforceProductFieldMap } from "../catalog/contract";
+import type { SalesforceAccountFieldMap } from "../customer/index";
+import type { UserIdMapping } from "../mappings/contract";
 
 // ============================================================================
 // Order Type Constants
diff --git a/packages/domain/orders/index.ts b/packages/domain/orders/index.ts
index 9f4ec597..60394268 100644
--- a/packages/domain/orders/index.ts
+++ b/packages/domain/orders/index.ts
@@ -19,13 +19,13 @@ export {
   SIM_TYPE,
   ORDER_FULFILLMENT_ERROR_CODE,
   type OrderFulfillmentErrorCode,
-} from "./contract.js";
+} from "./contract";
 
 // Schemas (includes derived types)
-export * from "./schema.js";
+export * from "./schema";
 
 // Validation (extended business rules)
-export * from "./validation.js";
+export * from "./validation";
 
 // Re-export types for convenience
 export type {
@@ -45,8 +45,8 @@ export type {
 } from './schema';
 
 // Provider adapters
-export * as Providers from "./providers/index.js";
+export * as Providers from "./providers/index";
 
 // Re-export provider types for convenience
-export * from "./providers/whmcs/raw.types.js";
-export * from "./providers/salesforce/raw.types.js";
+export * from "./providers/whmcs/raw.types";
+export * from "./providers/salesforce/raw.types";
diff --git a/packages/domain/orders/providers/index.ts b/packages/domain/orders/providers/index.ts
index 01a1cc8a..9503a0a6 100644
--- a/packages/domain/orders/providers/index.ts
+++ b/packages/domain/orders/providers/index.ts
@@ -2,10 +2,10 @@
  * Orders Domain - Providers
  */
 
-import * as WhmcsMapper from "./whmcs/mapper.js";
-import * as WhmcsRaw from "./whmcs/raw.types.js";
-import * as SalesforceMapper from "./salesforce/mapper.js";
-import * as SalesforceRaw from "./salesforce/raw.types.js";
+import * as WhmcsMapper from "./whmcs/mapper";
+import * as WhmcsRaw from "./whmcs/raw.types";
+import * as SalesforceMapper from "./salesforce/mapper";
+import * as SalesforceRaw from "./salesforce/raw.types";
 
 export const Whmcs = {
   ...WhmcsMapper,
@@ -25,7 +25,7 @@ export {
   SalesforceMapper,
   SalesforceRaw,
 };
-export * from "./whmcs/mapper.js";
-export * from "./whmcs/raw.types.js";
-export * from "./salesforce/mapper.js";
-export * from "./salesforce/raw.types.js";
+export * from "./whmcs/mapper";
+export * from "./whmcs/raw.types";
+export * from "./salesforce/mapper";
+export * from "./salesforce/raw.types";
diff --git a/packages/domain/orders/providers/salesforce/index.ts b/packages/domain/orders/providers/salesforce/index.ts
index fa8002ef..2dd11e02 100644
--- a/packages/domain/orders/providers/salesforce/index.ts
+++ b/packages/domain/orders/providers/salesforce/index.ts
@@ -1,2 +1,2 @@
-export * from "./raw.types.js";
-export * from "./mapper.js";
+export * from "./raw.types";
+export * from "./mapper";
diff --git a/packages/domain/orders/providers/salesforce/mapper.ts b/packages/domain/orders/providers/salesforce/mapper.ts
index fc3e276e..c597b742 100644
--- a/packages/domain/orders/providers/salesforce/mapper.ts
+++ b/packages/domain/orders/providers/salesforce/mapper.ts
@@ -9,12 +9,12 @@ import type {
   OrderItemDetails,
   OrderItemSummary,
   OrderSummary,
-} from "../../contract.js";
-import { orderDetailsSchema, orderSummarySchema, orderItemDetailsSchema } from "../../schema.js";
+} from "../../contract";
+import { orderDetailsSchema, orderSummarySchema, orderItemDetailsSchema } from "../../schema";
 import type {
   SalesforceOrderItemRecord,
   SalesforceOrderRecord,
-} from "./raw.types.js";
+} from "./raw.types";
 
 /**
  * Transform a Salesforce OrderItem record into domain details + summary.
diff --git a/packages/domain/orders/providers/whmcs/index.ts b/packages/domain/orders/providers/whmcs/index.ts
index 644fdb12..c95a1ab4 100644
--- a/packages/domain/orders/providers/whmcs/index.ts
+++ b/packages/domain/orders/providers/whmcs/index.ts
@@ -1,2 +1,2 @@
-export * from "./mapper.js";
-export * from "./raw.types.js";
+export * from "./mapper";
+export * from "./raw.types";
diff --git a/packages/domain/orders/providers/whmcs/mapper.ts b/packages/domain/orders/providers/whmcs/mapper.ts
index 6df1fd0f..4157034a 100644
--- a/packages/domain/orders/providers/whmcs/mapper.ts
+++ b/packages/domain/orders/providers/whmcs/mapper.ts
@@ -4,12 +4,12 @@
  * Transforms normalized order data to WHMCS API format.
  */
 
-import type { OrderDetails, OrderItemDetails } from "../../contract.js";
+import type { OrderDetails, OrderItemDetails } from "../../contract";
 import {
   type WhmcsOrderItem,
   type WhmcsAddOrderParams,
   type WhmcsAddOrderPayload,
-} from "./raw.types.js";
+} from "./raw.types";
 
 export interface OrderItemMappingResult {
   whmcsItems: WhmcsOrderItem[];
diff --git a/packages/domain/orders/validation.ts b/packages/domain/orders/validation.ts
index 024cdcb0..ec05d608 100644
--- a/packages/domain/orders/validation.ts
+++ b/packages/domain/orders/validation.ts
@@ -6,7 +6,7 @@
  */
 
 import { z } from "zod";
-import { orderBusinessValidationSchema } from "./schema.js";
+import { orderBusinessValidationSchema } from "./schema";
 
 // ============================================================================
 // SKU Business Rules Helpers
diff --git a/packages/domain/package.json b/packages/domain/package.json
index 8bf04294..94899728 100644
--- a/packages/domain/package.json
+++ b/packages/domain/package.json
@@ -1,7 +1,7 @@
 {
   "name": "@customer-portal/domain",
   "version": "1.0.0",
-  "type": "module",
+  "type": "commonjs",
   "description": "Unified domain layer with contracts, schemas, and provider mappers",
   "main": "./dist/index.js",
   "types": "./dist/index.d.ts",
diff --git a/packages/domain/payments/index.ts b/packages/domain/payments/index.ts
index 76ba14ed..b45aa5ae 100644
--- a/packages/domain/payments/index.ts
+++ b/packages/domain/payments/index.ts
@@ -7,10 +7,10 @@
  */
 
 // Constants
-export { PAYMENT_METHOD_TYPE, PAYMENT_GATEWAY_TYPE, type InvoicePaymentLink } from "./contract.js";
+export { PAYMENT_METHOD_TYPE, PAYMENT_GATEWAY_TYPE, type InvoicePaymentLink } from "./contract";
 
 // Schemas (includes derived types)
-export * from "./schema.js";
+export * from "./schema";
 
 // Re-export types for convenience
 export type {
@@ -20,10 +20,10 @@ export type {
   PaymentGatewayType,
   PaymentGateway,
   PaymentGatewayList,
-} from './schema.js';
+} from './schema';
 
 // Provider adapters
-export * as Providers from "./providers/index.js";
+export * as Providers from "./providers/index";
 
 // Re-export provider raw types (request and response)
 export type {
@@ -34,4 +34,4 @@ export type {
   WhmcsPaymentMethodListResponse,
   WhmcsPaymentGateway,
   WhmcsPaymentGatewayListResponse,
-} from "./providers/whmcs/raw.types.js";
+} from "./providers/whmcs/raw.types";
diff --git a/packages/domain/payments/providers/index.ts b/packages/domain/payments/providers/index.ts
index aa066ccc..507ead52 100644
--- a/packages/domain/payments/providers/index.ts
+++ b/packages/domain/payments/providers/index.ts
@@ -2,8 +2,8 @@
  * Payments Domain - Providers
  */
 
-import * as WhmcsMapper from "./whmcs/mapper.js";
-import * as WhmcsRaw from "./whmcs/raw.types.js";
+import * as WhmcsMapper from "./whmcs/mapper";
+import * as WhmcsRaw from "./whmcs/raw.types";
 
 export const Whmcs = {
   ...WhmcsMapper,
@@ -12,5 +12,5 @@ export const Whmcs = {
 };
 
 export { WhmcsMapper, WhmcsRaw };
-export * from "./whmcs/mapper.js";
-export * from "./whmcs/raw.types.js";
+export * from "./whmcs/mapper";
+export * from "./whmcs/raw.types";
diff --git a/packages/domain/payments/providers/whmcs/index.ts b/packages/domain/payments/providers/whmcs/index.ts
index 644fdb12..c95a1ab4 100644
--- a/packages/domain/payments/providers/whmcs/index.ts
+++ b/packages/domain/payments/providers/whmcs/index.ts
@@ -1,2 +1,2 @@
-export * from "./mapper.js";
-export * from "./raw.types.js";
+export * from "./mapper";
+export * from "./raw.types";
diff --git a/packages/domain/payments/providers/whmcs/mapper.ts b/packages/domain/payments/providers/whmcs/mapper.ts
index d037b26f..8c6a8612 100644
--- a/packages/domain/payments/providers/whmcs/mapper.ts
+++ b/packages/domain/payments/providers/whmcs/mapper.ts
@@ -2,14 +2,14 @@
  * WHMCS Payments Provider - Mapper
  */
 
-import type { PaymentMethod, PaymentGateway } from "../../contract.js";
-import { paymentMethodSchema, paymentGatewaySchema } from "../../schema.js";
+import type { PaymentMethod, PaymentGateway } from "../../contract";
+import { paymentMethodSchema, paymentGatewaySchema } from "../../schema";
 import {
   type WhmcsPaymentMethodRaw,
   type WhmcsPaymentGatewayRaw,
   whmcsPaymentMethodRawSchema,
   whmcsPaymentGatewayRawSchema,
-} from "./raw.types.js";
+} from "./raw.types";
 
 const PAYMENT_TYPE_MAP: Record<string, PaymentMethod["type"]> = {
   creditcard: "CreditCard",
diff --git a/packages/domain/sim/index.ts b/packages/domain/sim/index.ts
index 6a71c6aa..700a2f7e 100644
--- a/packages/domain/sim/index.ts
+++ b/packages/domain/sim/index.ts
@@ -7,13 +7,13 @@
  */
 
 // Constants
-export { SIM_STATUS, SIM_TYPE } from "./contract.js";
+export { SIM_STATUS, SIM_TYPE } from "./contract";
 
 // Schemas (includes derived types)
-export * from "./schema.js";
+export * from "./schema";
 
 // Validation functions
-export * from "./validation.js";
+export * from "./validation";
 
 // Re-export types for convenience
 export type {
@@ -34,7 +34,7 @@ export type {
   SimOrderActivationRequest,
   SimOrderActivationMnp,
   SimOrderActivationAddons,
-} from './schema.js';
+} from './schema';
 
 // Provider adapters
-export * as Providers from "./providers/index.js";
+export * as Providers from "./providers/index";
diff --git a/packages/domain/sim/providers/freebit/index.ts b/packages/domain/sim/providers/freebit/index.ts
index c6992c04..3838aa5c 100644
--- a/packages/domain/sim/providers/freebit/index.ts
+++ b/packages/domain/sim/providers/freebit/index.ts
@@ -1,7 +1,7 @@
-import * as Mapper from "./mapper.js";
-import * as RawTypes from "./raw.types.js";
-import * as Requests from "./requests.js";
-import * as Utils from "./utils.js";
+import * as Mapper from "./mapper";
+import * as RawTypes from "./raw.types";
+import * as Requests from "./requests";
+import * as Utils from "./utils";
 
 export const schemas = {
   accountDetails: Requests.freebitAccountDetailsRequestSchema,
@@ -51,10 +51,10 @@ export type EsimAddAccountResponse = ReturnType<typeof Mapper.transformFreebitEs
 export type EsimActivationResponse = ReturnType<typeof Mapper.transformFreebitEsimActivationResponse>;
 export type AuthResponse = ReturnType<typeof Mapper.transformFreebitAuthResponse>;
 
-export * from "./mapper.js";
-export * from "./raw.types.js";
-export * from "./requests.js";
-export * from "./utils.js";
+export * from "./mapper";
+export * from "./raw.types";
+export * from "./requests";
+export * from "./utils";
 
 export const Freebit = {
   ...Mapper,
diff --git a/packages/domain/sim/providers/freebit/mapper.ts b/packages/domain/sim/providers/freebit/mapper.ts
index fecf4383..053b3d64 100644
--- a/packages/domain/sim/providers/freebit/mapper.ts
+++ b/packages/domain/sim/providers/freebit/mapper.ts
@@ -2,8 +2,8 @@
  * Freebit SIM Provider - Mapper
  */
 
-import type { SimDetails, SimUsage, SimTopUpHistory, SimType, SimStatus } from "../../contract.js";
-import { simDetailsSchema, simUsageSchema, simTopUpHistorySchema } from "../../schema.js";
+import type { SimDetails, SimUsage, SimTopUpHistory, SimType, SimStatus } from "../../contract";
+import { simDetailsSchema, simUsageSchema, simTopUpHistorySchema } from "../../schema";
 import {
   type FreebitAccountDetailsRaw,
   type FreebitTrafficInfoRaw,
@@ -27,8 +27,8 @@ import {
   freebitCancelAccountRawSchema,
   freebitEsimReissueRawSchema,
   freebitEsimAddAccountRawSchema,
-} from "./raw.types.js";
-import { normalizeAccount } from "./utils.js";
+} from "./raw.types";
+import { normalizeAccount } from "./utils";
 
 function asString(value: unknown): string {
   if (typeof value === "string") return value;
diff --git a/packages/domain/sim/providers/index.ts b/packages/domain/sim/providers/index.ts
index a698aaa4..f15ef235 100644
--- a/packages/domain/sim/providers/index.ts
+++ b/packages/domain/sim/providers/index.ts
@@ -2,9 +2,9 @@
  * SIM Domain - Providers
  */
 
-import { Freebit as FreebitAggregated } from "./freebit/index.js";
-import * as FreebitModule from "./freebit/index.js";
+import { Freebit as FreebitAggregated } from "./freebit/index";
+import * as FreebitModule from "./freebit/index";
 
 export const Freebit = FreebitAggregated;
 export { FreebitModule };
-export * from "./freebit/index.js";
+export * from "./freebit/index";
diff --git a/packages/domain/sim/validation.ts b/packages/domain/sim/validation.ts
index 173b851c..3c258035 100644
--- a/packages/domain/sim/validation.ts
+++ b/packages/domain/sim/validation.ts
@@ -5,7 +5,7 @@
  * These functions contain no infrastructure dependencies.
  */
 
-import type { Subscription } from "../subscriptions/schema.js";
+import type { Subscription } from "../subscriptions/schema";
 
 /**
  * Check if a subscription is a SIM service
diff --git a/packages/domain/subscriptions/index.ts b/packages/domain/subscriptions/index.ts
index 6b5013ca..31975b6e 100644
--- a/packages/domain/subscriptions/index.ts
+++ b/packages/domain/subscriptions/index.ts
@@ -7,10 +7,10 @@
  */
 
 // Constants
-export { SUBSCRIPTION_STATUS, SUBSCRIPTION_CYCLE } from "./contract.js";
+export { SUBSCRIPTION_STATUS, SUBSCRIPTION_CYCLE } from "./contract";
 
 // Schemas (includes derived types)
-export * from "./schema.js";
+export * from "./schema";
 
 // Re-export types for convenience
 export type {
@@ -23,10 +23,10 @@ export type {
   SubscriptionStats,
   SimActionResponse,
   SimPlanChangeResult,
-} from './schema.js';
+} from './schema';
 
 // Provider adapters
-export * as Providers from "./providers/index.js";
+export * as Providers from "./providers/index";
 
 // Re-export provider raw types (request and response)
 export type {
diff --git a/packages/domain/subscriptions/providers/index.ts b/packages/domain/subscriptions/providers/index.ts
index a1dd4436..6e242545 100644
--- a/packages/domain/subscriptions/providers/index.ts
+++ b/packages/domain/subscriptions/providers/index.ts
@@ -2,8 +2,8 @@
  * Subscriptions Domain - Providers
  */
 
-import * as WhmcsMapper from "./whmcs/mapper.js";
-import * as WhmcsRaw from "./whmcs/raw.types.js";
+import * as WhmcsMapper from "./whmcs/mapper";
+import * as WhmcsRaw from "./whmcs/raw.types";
 
 export const Whmcs = {
   ...WhmcsMapper,
@@ -12,5 +12,5 @@ export const Whmcs = {
 };
 
 export { WhmcsMapper, WhmcsRaw };
-export * from "./whmcs/mapper.js";
-export * from "./whmcs/raw.types.js";
+export * from "./whmcs/mapper";
+export * from "./whmcs/raw.types";
diff --git a/packages/domain/subscriptions/providers/whmcs/index.ts b/packages/domain/subscriptions/providers/whmcs/index.ts
index 644fdb12..c95a1ab4 100644
--- a/packages/domain/subscriptions/providers/whmcs/index.ts
+++ b/packages/domain/subscriptions/providers/whmcs/index.ts
@@ -1,2 +1,2 @@
-export * from "./mapper.js";
-export * from "./raw.types.js";
+export * from "./mapper";
+export * from "./raw.types";
diff --git a/packages/domain/subscriptions/providers/whmcs/mapper.ts b/packages/domain/subscriptions/providers/whmcs/mapper.ts
index fb3ff3fc..6638161e 100644
--- a/packages/domain/subscriptions/providers/whmcs/mapper.ts
+++ b/packages/domain/subscriptions/providers/whmcs/mapper.ts
@@ -4,13 +4,13 @@
  * Transforms raw WHMCS product/service data into normalized subscription types.
  */
 
-import type { Subscription, SubscriptionStatus, SubscriptionCycle } from "../../contract.js";
-import { subscriptionSchema } from "../../schema.js";
+import type { Subscription, SubscriptionStatus, SubscriptionCycle } from "../../contract";
+import { subscriptionSchema } from "../../schema";
 import {
   type WhmcsProductRaw,
   whmcsProductRawSchema,
   whmcsCustomFieldsContainerSchema,
-} from "./raw.types.js";
+} from "./raw.types";
 
 export interface TransformSubscriptionOptions {
   defaultCurrencyCode?: string;
diff --git a/packages/domain/toolkit/formatting/index.ts b/packages/domain/toolkit/formatting/index.ts
index 54584657..55c18748 100644
--- a/packages/domain/toolkit/formatting/index.ts
+++ b/packages/domain/toolkit/formatting/index.ts
@@ -4,8 +4,8 @@
  * Formatting utilities for currency, dates, phone numbers, etc.
  */
 
-export * from "./currency.js";
-export * from "./date.js";
-export * from "./phone.js";
-export * from "./text.js";
+export * from "./currency";
+export * from "./date";
+export * from "./phone";
+export * from "./text";
 
diff --git a/packages/domain/toolkit/index.ts b/packages/domain/toolkit/index.ts
index 92210608..560e69ea 100644
--- a/packages/domain/toolkit/index.ts
+++ b/packages/domain/toolkit/index.ts
@@ -4,7 +4,7 @@
  * Utility functions and helpers used across all domain packages.
  */
 
-export * as Formatting from "./formatting/index.js";
-export * as Validation from "./validation/index.js";
-export * as Typing from "./typing/index.js";
+export * as Formatting from "./formatting/index";
+export * as Validation from "./validation/index";
+export * as Typing from "./typing/index";
 
diff --git a/packages/domain/toolkit/typing/index.ts b/packages/domain/toolkit/typing/index.ts
index 4bb111cf..20fed08a 100644
--- a/packages/domain/toolkit/typing/index.ts
+++ b/packages/domain/toolkit/typing/index.ts
@@ -4,7 +4,7 @@
  * TypeScript type utilities and runtime type checking.
  */
 
-export * from "./guards.js";
-export * from "./assertions.js";
-export * from "./helpers.js";
+export * from "./guards";
+export * from "./assertions";
+export * from "./helpers";
 
diff --git a/packages/domain/toolkit/validation/index.ts b/packages/domain/toolkit/validation/index.ts
index 8b5d8332..da2ec409 100644
--- a/packages/domain/toolkit/validation/index.ts
+++ b/packages/domain/toolkit/validation/index.ts
@@ -4,9 +4,9 @@
  * Validation utilities for common data types.
  */
 
-export * from "./email.js";
-export * from "./url.js";
-export * from "./string.js";
-export * from "./helpers.js";
+export * from "./email";
+export * from "./url";
+export * from "./string";
+export * from "./helpers";
 
 
diff --git a/packages/domain/tsconfig.json b/packages/domain/tsconfig.json
index 229185e3..93a2ffcf 100644
--- a/packages/domain/tsconfig.json
+++ b/packages/domain/tsconfig.json
@@ -1,7 +1,7 @@
 {
   "compilerOptions": {
     "target": "ES2022",
-    "module": "ESNext",
+    "module": "commonjs",
     "lib": ["ES2022"],
     "declaration": true,
     "declarationMap": true,