diff --git a/pnpm-lock.yaml b/pnpm-lock.yaml
index 76c5d48ea1..f8c065d672 100644
--- a/pnpm-lock.yaml
+++ b/pnpm-lock.yaml
@@ -2274,9 +2274,6 @@ importers:
       typescript:
         specifier: ^5.6.3
         version: 5.6.3
-      vitest:
-        specifier: 4.1.7
-        version: 4.1.7(@types/node@20.12.7)(vite@6.3.5(@types/node@20.12.7)(jiti@2.4.2)(terser@5.43.1)(yaml@2.7.0))
 
   services/libs/database:
     dependencies:
diff --git a/services/libs/data-access-layer/package.json b/services/libs/data-access-layer/package.json
index dbdfb90724..bcaadfe608 100644
--- a/services/libs/data-access-layer/package.json
+++ b/services/libs/data-access-layer/package.json
@@ -35,7 +35,6 @@
   "devDependencies": {
     "@crowd/test-kit": "workspace:*",
     "@types/node": "^20.8.2",
-    "typescript": "^5.6.3",
-    "vitest": "4.1.7"
+    "typescript": "^5.6.3"
   }
 }
diff --git a/services/libs/data-access-layer/src/affiliations/__tests__/affiliations.test.ts b/services/libs/data-access-layer/src/affiliations/index.test.ts
similarity index 96%
rename from services/libs/data-access-layer/src/affiliations/__tests__/affiliations.test.ts
rename to services/libs/data-access-layer/src/affiliations/index.test.ts
index d6acaef53d..97069cda84 100644
--- a/services/libs/data-access-layer/src/affiliations/__tests__/affiliations.test.ts
+++ b/services/libs/data-access-layer/src/affiliations/index.test.ts
@@ -1,12 +1,25 @@
+/**
+ * Legacy suite — keep for now, migrate when this module is next touched.
+ *
+ * This covers the API read path (`resolveAffiliationsByMemberIds` / pure
+ * `buildTimeline` + `selectPrimaryWorkExperience`), not the activity-write
+ * path in `member-organization-affiliation/`.
+ *
+ * Style is outdated vs current CDP testing:
+ * - mocked `qx` + hand-built rows instead of `@crowd/test-kit` factories
+ * - does not use schema-aligned `*DbInsert` types (ADR-0006)
+ * - does not follow factory primitives / defaults (ADR-0007)
+ * - does not follow named DB-backed scenarios (ADR-0008)
+ *
+ * Reference for the target style:
+ * `../member-organization-affiliation/index.test.ts`
+ */
 import { beforeEach, describe, expect, it, vi } from 'vitest'
 
-import type { QueryExecutor } from '../../queryExecutor'
-import {
-  buildTimeline,
-  resolveAffiliationsByMemberIds,
-  selectPrimaryWorkExperience,
-} from '../index'
-import type { IWorkExperienceResolution } from '../index'
+import type { QueryExecutor } from '../queryExecutor'
+
+import { buildTimeline, resolveAffiliationsByMemberIds, selectPrimaryWorkExperience } from './index'
+import type { IWorkExperienceResolution } from './index'
 
 // Mocks are hoisted before imports — intercept transitive dependencies that
 // require a live database or external services.
diff --git a/services/libs/data-access-layer/src/member-organization-affiliation/index.test.ts b/services/libs/data-access-layer/src/member-organization-affiliation/index.test.ts
index d6872a80ec..4fcdfee2fd 100644
--- a/services/libs/data-access-layer/src/member-organization-affiliation/index.test.ts
+++ b/services/libs/data-access-layer/src/member-organization-affiliation/index.test.ts
@@ -1251,6 +1251,14 @@ describe('refreshMemberOrganizationAffiliations', () => {
     ])
 
     await createActivityRelations(qx, [
+      ...generateActivityRelations({
+        memberId: member.id,
+        segmentId: kubernetes.id,
+        identities,
+        count: 20,
+        // Before MSA dateStart — must stay on the employer timeline.
+        timestamp: { from: '2020-06-01T00:00:00.000Z', to: '2020-09-01T00:00:00.000Z' },
+      }),
       ...generateActivityRelations({
         memberId: member.id,
         segmentId: kubernetes.id,
@@ -1270,7 +1278,8 @@ describe('refreshMemberOrganizationAffiliations', () => {
     await refreshMemberOrganizationAffiliations(qx, member.id)
 
     expect(await countByOrg(qx, member.id, kubernetes.id, sponsor.id)).toBe(40)
-    expect(await countByOrg(qx, member.id, kubernetes.id, employer.id)).toBe(30)
+    // Pre-window (20) + post-window (30) both fall outside the MSA and stay on MO.
+    expect(await countByOrg(qx, member.id, kubernetes.id, employer.id)).toBe(50)
   })
 
   test('email-domain activities route to matching org over the date timeline', async ({ qx }) => {