diff --git a/apps/bff/package.json b/apps/bff/package.json
index 440b6440..087e1bec 100644
--- a/apps/bff/package.json
+++ b/apps/bff/package.json
@@ -1,6 +1,7 @@
 {
   "name": "@customer-portal/bff",
   "version": "1.0.0",
+  "type": "module",
   "description": "Backend for Frontend API",
   "author": "",
   "private": true,
diff --git a/apps/bff/tsconfig.json b/apps/bff/tsconfig.json
index a30fcc97..44837be1 100644
--- a/apps/bff/tsconfig.json
+++ b/apps/bff/tsconfig.json
@@ -31,8 +31,9 @@
   },
   "ts-node": {
     "transpileOnly": true,
+    "esm": true,
     "compilerOptions": {
-      "module": "CommonJS"
+      "module": "Node16"
     }
   },
   "include": ["src/**/*", "scripts/**/*", "src/types/**/*"],
diff --git a/packages/domain/auth/schema.ts b/packages/domain/auth/schema.ts
index 70d910cf..1e56c91d 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";
-import { addressSchema, userSchema } from "../customer/schema";
+import { emailSchema, nameSchema, passwordSchema, phoneSchema } from "../common/schema.js";
+import { addressSchema, userSchema } from "../customer/schema.js";
 
 // ============================================================================
 // Authentication Request Schemas
diff --git a/packages/domain/billing/providers/whmcs/mapper.ts b/packages/domain/billing/providers/whmcs/mapper.ts
index 31fe1ffb..a8f52a05 100644
--- a/packages/domain/billing/providers/whmcs/mapper.ts
+++ b/packages/domain/billing/providers/whmcs/mapper.ts
@@ -4,8 +4,8 @@
  * Transforms raw WHMCS invoice data into normalized billing domain types.
  */
 
-import type { Invoice, InvoiceItem } from "../../contract";
-import { invoiceSchema } from "../../schema";
+import type { Invoice, InvoiceItem } from "../../contract.js";
+import { invoiceSchema } from "../../schema.js";
 import {
   type WhmcsInvoiceRaw,
   whmcsInvoiceRawSchema,
diff --git a/packages/domain/catalog/providers/salesforce/mapper.ts b/packages/domain/catalog/providers/salesforce/mapper.ts
index 65ee210c..5102cc0d 100644
--- a/packages/domain/catalog/providers/salesforce/mapper.ts
+++ b/packages/domain/catalog/providers/salesforce/mapper.ts
@@ -13,7 +13,7 @@ import type {
   SimCatalogProduct,
   SimActivationFeeCatalogItem,
   VpnCatalogProduct,
-} from "../../contract";
+} from "../../contract.js";
 import type {
   SalesforceProduct2WithPricebookEntries,
   SalesforcePricebookEntryRecord,
diff --git a/packages/domain/customer/providers/portal/mapper.ts b/packages/domain/customer/providers/portal/mapper.ts
index a53fe01c..d55fca00 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";
+import { userAuthSchema } from "../../schema.js";
 import type { PrismaUserRaw } from "./types.js";
-import type { UserAuth } from "../../schema";
+import type { UserAuth } from "../../schema.js";
 
 /**
  * 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 e9266b0e..b60d1ef6 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";
+import type { UserRole } from "../../schema.js";
 
 /**
  * Raw Prisma user data from portal database
diff --git a/packages/domain/customer/providers/whmcs/mapper.ts b/packages/domain/customer/providers/whmcs/mapper.ts
index 2b583fbe..85802a6e 100644
--- a/packages/domain/customer/providers/whmcs/mapper.ts
+++ b/packages/domain/customer/providers/whmcs/mapper.ts
@@ -7,8 +7,8 @@
 
 import { z } from "zod";
 
-import type { WhmcsClient, Address } from "../../schema";
-import { whmcsClientSchema, addressSchema } from "../../schema";
+import type { WhmcsClient, Address } from "../../schema.js";
+import { whmcsClientSchema, addressSchema } from "../../schema.js";
 import {
   whmcsClientSchema as whmcsRawClientSchema,
   whmcsClientResponseSchema,
diff --git a/packages/domain/customer/schema.ts b/packages/domain/customer/schema.ts
index 7ecfd574..9e2ed205 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";
+import { countryCodeSchema } from "../common/schema.js";
 
 // ============================================================================
 // Helper Schemas
diff --git a/packages/domain/dashboard/contract.ts b/packages/domain/dashboard/contract.ts
index 0d4733c8..12133407 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";
-import type { Invoice } from "../billing/contract";
+import type { IsoDateTimeString } from "../common/types.js";
+import type { Invoice } from "../billing/contract.js";
 
 export type ActivityType =
   | "invoice_created"
diff --git a/packages/domain/mappings/contract.ts b/packages/domain/mappings/contract.ts
index 9bf0b6f1..54cf8089 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";
+import type { IsoDateTimeString } from "../common/types.js";
 
 export interface UserIdMapping {
   id: string;
diff --git a/packages/domain/orders/contract.ts b/packages/domain/orders/contract.ts
index 5279a51c..8450fed8 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";
-import type { SalesforceAccountFieldMap } from "../customer";
-import type { UserIdMapping } from "../mappings/contract";
+import type { SalesforceProductFieldMap } from "../catalog/contract.js";
+import type { SalesforceAccountFieldMap } from "../customer/index.js";
+import type { UserIdMapping } from "../mappings/contract.js";
 
 // ============================================================================
 // Order Type Constants
diff --git a/packages/domain/orders/providers/salesforce/mapper.ts b/packages/domain/orders/providers/salesforce/mapper.ts
index bf56d3b3..fc3e276e 100644
--- a/packages/domain/orders/providers/salesforce/mapper.ts
+++ b/packages/domain/orders/providers/salesforce/mapper.ts
@@ -9,8 +9,8 @@ import type {
   OrderItemDetails,
   OrderItemSummary,
   OrderSummary,
-} from "../../contract";
-import { orderDetailsSchema, orderSummarySchema, orderItemDetailsSchema } from "../../schema";
+} from "../../contract.js";
+import { orderDetailsSchema, orderSummarySchema, orderItemDetailsSchema } from "../../schema.js";
 import type {
   SalesforceOrderItemRecord,
   SalesforceOrderRecord,
diff --git a/packages/domain/orders/providers/whmcs/mapper.ts b/packages/domain/orders/providers/whmcs/mapper.ts
index ab7d8d4c..6df1fd0f 100644
--- a/packages/domain/orders/providers/whmcs/mapper.ts
+++ b/packages/domain/orders/providers/whmcs/mapper.ts
@@ -4,7 +4,7 @@
  * Transforms normalized order data to WHMCS API format.
  */
 
-import type { OrderDetails, OrderItemDetails } from "../../contract";
+import type { OrderDetails, OrderItemDetails } from "../../contract.js";
 import {
   type WhmcsOrderItem,
   type WhmcsAddOrderParams,
diff --git a/packages/domain/package.json b/packages/domain/package.json
index 512f12c3..8bf04294 100644
--- a/packages/domain/package.json
+++ b/packages/domain/package.json
@@ -1,6 +1,7 @@
 {
   "name": "@customer-portal/domain",
   "version": "1.0.0",
+  "type": "module",
   "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/providers/whmcs/mapper.ts b/packages/domain/payments/providers/whmcs/mapper.ts
index 2a54f3ef..d037b26f 100644
--- a/packages/domain/payments/providers/whmcs/mapper.ts
+++ b/packages/domain/payments/providers/whmcs/mapper.ts
@@ -2,8 +2,8 @@
  * WHMCS Payments Provider - Mapper
  */
 
-import type { PaymentMethod, PaymentGateway } from "../../contract";
-import { paymentMethodSchema, paymentGatewaySchema } from "../../schema";
+import type { PaymentMethod, PaymentGateway } from "../../contract.js";
+import { paymentMethodSchema, paymentGatewaySchema } from "../../schema.js";
 import {
   type WhmcsPaymentMethodRaw,
   type WhmcsPaymentGatewayRaw,
diff --git a/packages/domain/sim/providers/freebit/mapper.ts b/packages/domain/sim/providers/freebit/mapper.ts
index 1de32b27..fecf4383 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";
-import { simDetailsSchema, simUsageSchema, simTopUpHistorySchema } from "../../schema";
+import type { SimDetails, SimUsage, SimTopUpHistory, SimType, SimStatus } from "../../contract.js";
+import { simDetailsSchema, simUsageSchema, simTopUpHistorySchema } from "../../schema.js";
 import {
   type FreebitAccountDetailsRaw,
   type FreebitTrafficInfoRaw,
diff --git a/packages/domain/sim/validation.ts b/packages/domain/sim/validation.ts
index 3c258035..173b851c 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";
+import type { Subscription } from "../subscriptions/schema.js";
 
 /**
  * Check if a subscription is a SIM service
diff --git a/packages/domain/subscriptions/providers/whmcs/mapper.ts b/packages/domain/subscriptions/providers/whmcs/mapper.ts
index eb7b54b9..fb3ff3fc 100644
--- a/packages/domain/subscriptions/providers/whmcs/mapper.ts
+++ b/packages/domain/subscriptions/providers/whmcs/mapper.ts
@@ -4,8 +4,8 @@
  * Transforms raw WHMCS product/service data into normalized subscription types.
  */
 
-import type { Subscription, SubscriptionStatus, SubscriptionCycle } from "../../contract";
-import { subscriptionSchema } from "../../schema";
+import type { Subscription, SubscriptionStatus, SubscriptionCycle } from "../../contract.js";
+import { subscriptionSchema } from "../../schema.js";
 import {
   type WhmcsProductRaw,
   whmcsProductRawSchema,