diff --git a/backend/src/database/migrations/V1789112777__skip-reason-to-project-catalog.sql b/backend/src/database/migrations/V1789112777__skip-reason-to-project-catalog.sql
new file mode 100644
index 0000000000..f7d80e4b34
--- /dev/null
+++ b/backend/src/database/migrations/V1789112777__skip-reason-to-project-catalog.sql
@@ -0,0 +1,2 @@
+ALTER TABLE "projectCatalog"
+  ADD COLUMN IF NOT EXISTS "skipReason" TEXT;
diff --git a/services/apps/automatic_onboarding_worker/src/activities/activities.ts b/services/apps/automatic_onboarding_worker/src/activities/activities.ts
index 1463ca00e3..43964ffb54 100644
--- a/services/apps/automatic_onboarding_worker/src/activities/activities.ts
+++ b/services/apps/automatic_onboarding_worker/src/activities/activities.ts
@@ -2,14 +2,22 @@ import {
   findProjectCatalogById,
   findProjectCatalogPendingOnboarding,
   markProjectCatalogOnboardingFailed,
+  markProjectCatalogOnboardingSkipped,
   updateProjectCatalog,
 } from '@crowd/data-access-layer'
+import {
+  InsightsProjectField,
+  findInsightsProjectBySlugIncludingDeleted,
+} from '@crowd/data-access-layer/src/collections'
 import { IDbProjectCatalog } from '@crowd/data-access-layer/src/project-catalog/types'
 import { pgpQx } from '@crowd/data-access-layer/src/queryExecutor'
 import { getServiceLogger } from '@crowd/logging'
 
 import { svc } from '../main'
-import { onboardProject } from '../onboarder/onboarder'
+import { deriveProjectSlug, onboardProject } from '../onboarder/onboarder'
+import { OnboardAndUpdateProjectOutcome } from '../types'
+
+import { buildInsightsProjectSkipReason } from './insightsProjectSkip'
 
 const log = getServiceLogger()
 
@@ -33,7 +41,17 @@ async function findAlreadyOnboarded(
   return fresh?.onboardedAt ? fresh : null
 }
 
-export async function onboardAndUpdateProject(project: IDbProjectCatalog): Promise<void> {
+async function findDeletedInsightsProjectBySlug(qx: ReturnType<typeof pgpQx>, projectSlug: string) {
+  const slug = deriveProjectSlug(projectSlug)
+  const insightsProject = await findInsightsProjectBySlugIncludingDeleted(qx, slug, [
+    InsightsProjectField.DELETED_AT,
+  ])
+  return insightsProject?.deletedAt ? insightsProject : null
+}
+
+export async function onboardAndUpdateProject(
+  project: IDbProjectCatalog,
+): Promise<OnboardAndUpdateProjectOutcome> {
   const qx = pgpQx(svc.postgres.writer.connection())
   const startTime = Date.now()
 
@@ -44,7 +62,38 @@ export async function onboardAndUpdateProject(project: IDbProjectCatalog): Promi
       { id: project.id, repoUrl: project.repoUrl, onboardedAt: fresh.onboardedAt },
       'Project already onboarded, skipping API call.',
     )
-    return
+    return 'already-onboarded'
+  }
+
+  const deletedInsightsProject = await findDeletedInsightsProjectBySlug(qx, project.projectSlug)
+  if (deletedInsightsProject) {
+    const reason = buildInsightsProjectSkipReason(
+      project.projectSlug,
+      deletedInsightsProject.deletedAt,
+    )
+    const updatedRows = await markProjectCatalogOnboardingSkipped(qx, project.id, reason)
+    if (updatedRows > 0) {
+      log.info({ id: project.id, repoUrl: project.repoUrl, reason }, 'Onboarding skipped.')
+      return 'skipped'
+    }
+
+    const current = await findProjectCatalogById(qx, project.id)
+    if (current?.onboardedAt) {
+      log.info(
+        { id: project.id, repoUrl: project.repoUrl, onboardedAt: current.onboardedAt },
+        'Project already onboarded, skipping API call.',
+      )
+      return 'already-onboarded'
+    }
+    if (current?.action === 'skip') {
+      log.info({ id: project.id, repoUrl: project.repoUrl }, 'Project already skipped.')
+      return 'skipped'
+    }
+    log.info(
+      { id: project.id, repoUrl: project.repoUrl, action: current?.action },
+      'Skip guard was a no-op; project catalog row changed concurrently, not calling onboarding API.',
+    )
+    return 'catalog-changed'
   }
 
   log.info({ id: project.id, repoUrl: project.repoUrl }, 'Starting onboarding.')
@@ -72,6 +121,8 @@ export async function onboardAndUpdateProject(project: IDbProjectCatalog): Promi
     { id: project.id, repoUrl: project.repoUrl, segmentId: result.segmentId, elapsedSeconds },
     'Onboarding complete.',
   )
+
+  return 'onboarded'
 }
 
 export async function markProjectOnboardingFailed(
diff --git a/services/apps/automatic_onboarding_worker/src/activities/insightsProjectSkip.test.ts b/services/apps/automatic_onboarding_worker/src/activities/insightsProjectSkip.test.ts
new file mode 100644
index 0000000000..80e7d69858
--- /dev/null
+++ b/services/apps/automatic_onboarding_worker/src/activities/insightsProjectSkip.test.ts
@@ -0,0 +1,16 @@
+import { describe, expect, it } from 'vitest'
+
+import { buildInsightsProjectSkipReason } from './insightsProjectSkip'
+
+describe('buildInsightsProjectSkipReason', () => {
+  it('normalizes the project slug and includes the deletion date', () => {
+    const reason = buildInsightsProjectSkipReason(
+      'nonlf_gerritcodereview-gerrit',
+      '2026-04-10T00:00:00.000Z',
+    )
+
+    expect(reason).toBe(
+      "Insights project 'nonlf-gerritcodereview-gerrit' was deleted on 2026-04-10T00:00:00.000Z; onboarding skipped for manual review",
+    )
+  })
+})
diff --git a/services/apps/automatic_onboarding_worker/src/activities/insightsProjectSkip.ts b/services/apps/automatic_onboarding_worker/src/activities/insightsProjectSkip.ts
new file mode 100644
index 0000000000..f8fddd6810
--- /dev/null
+++ b/services/apps/automatic_onboarding_worker/src/activities/insightsProjectSkip.ts
@@ -0,0 +1,8 @@
+import { deriveProjectSlug } from '../onboarder/onboarder'
+
+// A soft-deleted insightsProjects row still owns its slug (the unique index can't be made
+// partial on deletedAt: three FKs reference it), so segment creation would 500 on it.
+export function buildInsightsProjectSkipReason(projectSlug: string, deletedAt: string): string {
+  const slug = deriveProjectSlug(projectSlug)
+  return `Insights project '${slug}' was deleted on ${deletedAt}; onboarding skipped for manual review`
+}
diff --git a/services/apps/automatic_onboarding_worker/src/onboarder/onboarder.test.ts b/services/apps/automatic_onboarding_worker/src/onboarder/onboarder.test.ts
new file mode 100644
index 0000000000..3b87aaae33
--- /dev/null
+++ b/services/apps/automatic_onboarding_worker/src/onboarder/onboarder.test.ts
@@ -0,0 +1,27 @@
+import { describe, expect, it } from 'vitest'
+
+import { readErrorBody } from './onboarder'
+
+describe('readErrorBody', () => {
+  it('returns the response body text', async () => {
+    const response = new Response('{"error":"insightsProjects slug already exists"}')
+
+    expect(await readErrorBody(response)).toBe('{"error":"insightsProjects slug already exists"}')
+  })
+
+  it('truncates a body longer than 500 characters', async () => {
+    const response = new Response('a'.repeat(600))
+
+    const body = await readErrorBody(response)
+
+    expect(body).toBe(`${'a'.repeat(500)}…`)
+  })
+
+  it('returns an empty string when the body cannot be read', async () => {
+    const response = new Response(null)
+    // Consuming the body once locks the stream, so a second read fails.
+    await response.text()
+
+    expect(await readErrorBody(response)).toBe('')
+  })
+})
diff --git a/services/apps/automatic_onboarding_worker/src/onboarder/onboarder.ts b/services/apps/automatic_onboarding_worker/src/onboarder/onboarder.ts
index c82c49340a..ec822065f0 100644
--- a/services/apps/automatic_onboarding_worker/src/onboarder/onboarder.ts
+++ b/services/apps/automatic_onboarding_worker/src/onboarder/onboarder.ts
@@ -12,6 +12,16 @@ interface ISegmentQueryResponse {
 const SEGMENT_QUERY_PAGE_SIZE = 20
 const BACKEND_REQUEST_TIMEOUT_MS = 30_000
 const GITHUB_REQUEST_TIMEOUT_MS = 10_000
+const ERROR_BODY_MAX_LENGTH = 500
+
+export async function readErrorBody(response: Response): Promise<string> {
+  try {
+    const body = await response.text()
+    return body.length > ERROR_BODY_MAX_LENGTH ? `${body.slice(0, ERROR_BODY_MAX_LENGTH)}…` : body
+  } catch {
+    return ''
+  }
+}
 
 export function deriveProjectName(repoName: string): string {
   return repoName
@@ -99,7 +109,9 @@ async function queryProjectByName(
     })
 
     if (!response.ok) {
-      throw new Error(`Segment query returned HTTP ${response.status}: ${response.statusText}`)
+      throw new Error(
+        `Segment query returned HTTP ${response.status}: ${response.statusText} - ${await readErrorBody(response)}`,
+      )
     }
 
     const body = (await response.json()) as ISegmentQueryResponse
@@ -139,7 +151,9 @@ async function createProjectSegment(
   })
 
   if (!response.ok) {
-    throw new Error(`Segment creation returned HTTP ${response.status}: ${response.statusText}`)
+    throw new Error(
+      `Segment creation returned HTTP ${response.status}: ${response.statusText} - ${await readErrorBody(response)}`,
+    )
   }
 
   // POST /segment/project does not return the created segment's id in its response body; re-query by name to get it.
@@ -211,7 +225,9 @@ async function createGithubIntegration(
   })
 
   if (!response.ok) {
-    throw new Error(`GitHub integration returned HTTP ${response.status}: ${response.statusText}`)
+    throw new Error(
+      `GitHub integration returned HTTP ${response.status}: ${response.statusText} - ${await readErrorBody(response)}`,
+    )
   }
 }
 
diff --git a/services/apps/automatic_onboarding_worker/src/types.ts b/services/apps/automatic_onboarding_worker/src/types.ts
index cb0f970d90..59786e75ca 100644
--- a/services/apps/automatic_onboarding_worker/src/types.ts
+++ b/services/apps/automatic_onboarding_worker/src/types.ts
@@ -1,3 +1,9 @@
 export interface IOnboardProjectsInput {
   batchSize?: number
 }
+
+export type OnboardAndUpdateProjectOutcome =
+  | 'onboarded'
+  | 'skipped'
+  | 'already-onboarded'
+  | 'catalog-changed'
diff --git a/services/apps/automatic_onboarding_worker/src/workflows/onboardProjects.ts b/services/apps/automatic_onboarding_worker/src/workflows/onboardProjects.ts
index 48fa3587e5..890dd1c307 100644
--- a/services/apps/automatic_onboarding_worker/src/workflows/onboardProjects.ts
+++ b/services/apps/automatic_onboarding_worker/src/workflows/onboardProjects.ts
@@ -36,6 +36,8 @@ export async function onboardProjects(input: IOnboardProjectsInput = {}): Promis
   log.info(`Onboarding ${projects.length} project(s) (batch size: ${batchSize}).`)
 
   let succeeded = 0
+  let skipped = 0
+  let racedOut = 0
   let failed = 0
 
   for (let i = 0; i < projects.length; i++) {
@@ -43,8 +45,14 @@ export async function onboardProjects(input: IOnboardProjectsInput = {}): Promis
     log.info(`[${i + 1}/${projects.length}] Onboarding: ${project.repoUrl}`)
 
     try {
-      await onboardActivities.onboardAndUpdateProject(project)
-      succeeded++
+      const outcome = await onboardActivities.onboardAndUpdateProject(project)
+      if (outcome === 'skipped') {
+        skipped++
+      } else if (outcome === 'catalog-changed') {
+        racedOut++
+      } else {
+        succeeded++
+      }
     } catch (err) {
       // Activity-level retries are already exhausted at this point — mark as a
       // terminal error so the daily schedule stops retrying this project forever.
@@ -64,6 +72,6 @@ export async function onboardProjects(input: IOnboardProjectsInput = {}): Promis
   }
 
   log.info(
-    `Batch onboarding complete. total=${projects.length} succeeded=${succeeded} failed=${failed}`,
+    `Batch onboarding complete. total=${projects.length} succeeded=${succeeded} skipped=${skipped} racedOut=${racedOut} failed=${failed}`,
   )
 }
diff --git a/services/libs/data-access-layer/src/collections/index.test.ts b/services/libs/data-access-layer/src/collections/index.test.ts
new file mode 100644
index 0000000000..e526a28e1a
--- /dev/null
+++ b/services/libs/data-access-layer/src/collections/index.test.ts
@@ -0,0 +1,55 @@
+import { test as base, describe, expect } from 'vitest'
+
+import { withQx } from '@crowd/test-kit/db'
+
+import {
+  InsightsProjectField,
+  createInsightsProject,
+  deleteInsightsProject,
+  findInsightsProjectBySlugIncludingDeleted,
+} from './index'
+
+const test = withQx(base)
+
+describe('findInsightsProjectBySlugIncludingDeleted', () => {
+  test('finds a soft-deleted row by slug, with deletedAt set', async ({ qx }) => {
+    const created = await createInsightsProject(qx, {
+      name: 'Gerrit',
+      slug: 'gerritcodereview-gerrit',
+      isLF: false,
+    })
+    await deleteInsightsProject(qx, created.id)
+
+    const found = await findInsightsProjectBySlugIncludingDeleted(qx, 'gerritcodereview-gerrit', [
+      InsightsProjectField.ID,
+      InsightsProjectField.DELETED_AT,
+    ])
+
+    expect(found?.id).toBe(created.id)
+    expect(found?.deletedAt).not.toBeNull()
+  })
+
+  test('finds a live row by slug, with deletedAt null', async ({ qx }) => {
+    const created = await createInsightsProject(qx, {
+      name: 'Kubernetes',
+      slug: 'kubernetes-kubernetes',
+      isLF: true,
+    })
+
+    const found = await findInsightsProjectBySlugIncludingDeleted(qx, 'kubernetes-kubernetes', [
+      InsightsProjectField.ID,
+      InsightsProjectField.DELETED_AT,
+    ])
+
+    expect(found?.id).toBe(created.id)
+    expect(found?.deletedAt).toBeNull()
+  })
+
+  test('returns null when no row has the slug', async ({ qx }) => {
+    const found = await findInsightsProjectBySlugIncludingDeleted(qx, 'does-not-exist', [
+      InsightsProjectField.ID,
+    ])
+
+    expect(found).toBeNull()
+  })
+})
diff --git a/services/libs/data-access-layer/src/collections/index.ts b/services/libs/data-access-layer/src/collections/index.ts
index be5bc75aa9..d62968dbf9 100644
--- a/services/libs/data-access-layer/src/collections/index.ts
+++ b/services/libs/data-access-layer/src/collections/index.ts
@@ -196,6 +196,20 @@ export async function queryInsightsProjects<T extends InsightsProjectField>(
   return queryTable(qx, 'insightsProjects', Object.values(InsightsProjectField), opts)
 }
 
+export async function findInsightsProjectBySlugIncludingDeleted<T extends InsightsProjectField>(
+  qx: QueryExecutor,
+  slug: string,
+  fields: T[],
+): Promise<QueryResult<T> | null> {
+  const rows = await queryTable(qx, 'insightsProjects', Object.values(InsightsProjectField), {
+    fields,
+    filter: { slug: { eq: slug } },
+    limit: 1,
+  })
+
+  return rows.length > 0 ? rows[0] : null
+}
+
 export async function createInsightsProject(
   qx: QueryExecutor,
   insightProject: Partial<IInsightsProject>,
diff --git a/services/libs/data-access-layer/src/project-catalog/projectCatalog.test.ts b/services/libs/data-access-layer/src/project-catalog/projectCatalog.test.ts
new file mode 100644
index 0000000000..f0bfcfec1a
--- /dev/null
+++ b/services/libs/data-access-layer/src/project-catalog/projectCatalog.test.ts
@@ -0,0 +1,73 @@
+import { test as base, describe, expect } from 'vitest'
+
+import { withQx } from '@crowd/test-kit/db'
+
+import {
+  findProjectCatalogById,
+  insertProjectCatalog,
+  markProjectCatalogOnboardingSkipped,
+  updateProjectCatalog,
+} from './projectCatalog'
+
+const test = withQx(base)
+
+function catalogRow(overrides: Partial<Parameters<typeof insertProjectCatalog>[1]> = {}) {
+  return {
+    projectSlug: 'gerritcodereview-gerrit',
+    repoName: 'gerrit',
+    repoUrl: 'https://github.com/gerritcodereview/gerrit',
+    action: 'onboard' as const,
+    ...overrides,
+  }
+}
+
+describe('markProjectCatalogOnboardingSkipped', () => {
+  test('transitions a pending row to skip with the reason, and clears a prior onboarding error', async ({
+    qx,
+  }) => {
+    const inserted = await insertProjectCatalog(qx, catalogRow())
+    await updateProjectCatalog(qx, inserted.id, {
+      onboardingError: 'Segment creation returned HTTP 500: Internal Server Error',
+    })
+
+    const updatedRows = await markProjectCatalogOnboardingSkipped(
+      qx,
+      inserted.id,
+      "Insights project 'gerritcodereview-gerrit' was deleted on 2026-04-10; onboarding skipped for manual review",
+    )
+
+    const row = await findProjectCatalogById(qx, inserted.id)
+    expect(updatedRows).toBe(1)
+    expect(row?.action).toBe('skip')
+    expect(row?.skipReason).toBe(
+      "Insights project 'gerritcodereview-gerrit' was deleted on 2026-04-10; onboarding skipped for manual review",
+    )
+    expect(row?.onboardingError).toBeNull()
+  })
+
+  test('does not touch a row whose action is no longer onboard', async ({ qx }) => {
+    const inserted = await insertProjectCatalog(qx, catalogRow({ action: 'error' }))
+
+    const updatedRows = await markProjectCatalogOnboardingSkipped(qx, inserted.id, 'some reason')
+
+    const row = await findProjectCatalogById(qx, inserted.id)
+    expect(updatedRows).toBe(0)
+    expect(row?.action).toBe('error')
+    expect(row?.skipReason).toBeNull()
+  })
+
+  test('does not touch a row already onboarded', async ({ qx }) => {
+    const inserted = await insertProjectCatalog(qx, catalogRow())
+    await updateProjectCatalog(qx, inserted.id, {
+      action: 'onboarded',
+      onboardedAt: new Date().toISOString(),
+    })
+
+    const updatedRows = await markProjectCatalogOnboardingSkipped(qx, inserted.id, 'some reason')
+
+    const row = await findProjectCatalogById(qx, inserted.id)
+    expect(updatedRows).toBe(0)
+    expect(row?.action).toBe('onboarded')
+    expect(row?.skipReason).toBeNull()
+  })
+})
diff --git a/services/libs/data-access-layer/src/project-catalog/projectCatalog.ts b/services/libs/data-access-layer/src/project-catalog/projectCatalog.ts
index 63c72b42a9..f4768f8262 100644
--- a/services/libs/data-access-layer/src/project-catalog/projectCatalog.ts
+++ b/services/libs/data-access-layer/src/project-catalog/projectCatalog.ts
@@ -23,6 +23,7 @@ const PROJECT_CATALOG_COLUMNS = [
   'evaluatedAt',
   'onboardedAt',
   'onboardingError',
+  'skipReason',
   'syncedAt',
   'createdAt',
   'updatedAt',
@@ -518,6 +519,10 @@ export async function updateProjectCatalog(
     setClauses.push('"onboardingError" = $(onboardingError)')
     params.onboardingError = data.onboardingError
   }
+  if (data.skipReason !== undefined) {
+    setClauses.push('"skipReason" = $(skipReason)')
+    params.skipReason = data.skipReason
+  }
 
   if (setClauses.length === 0) {
     return findProjectCatalogById(qx, id)
@@ -551,6 +556,23 @@ export async function markProjectCatalogOnboardingFailed(
   )
 }
 
+// Guarded like markProjectCatalogOnboardingFailed: a concurrent manual action wins.
+// onboardingError is cleared in case this row was previously failed and requeued.
+export async function markProjectCatalogOnboardingSkipped(
+  qx: QueryExecutor,
+  id: string,
+  reason: string,
+): Promise<number> {
+  return qx.result(
+    `
+    UPDATE "projectCatalog"
+    SET "action" = 'skip', "skipReason" = $(reason), "onboardingError" = NULL, "updatedAt" = NOW()
+    WHERE id = $(id) AND "action" = 'onboard' AND "onboardedAt" IS NULL
+    `,
+    { id, reason },
+  )
+}
+
 // Guarded like markProjectCatalogOnboardingFailed above: a manual request
 // (POST /project-catalog) may have moved the row out of 'evaluate' while this
 // evaluation was in flight — in that case the manual action wins and this
diff --git a/services/libs/data-access-layer/src/project-catalog/types.ts b/services/libs/data-access-layer/src/project-catalog/types.ts
index f3822f3bb0..abfb1af250 100644
--- a/services/libs/data-access-layer/src/project-catalog/types.ts
+++ b/services/libs/data-access-layer/src/project-catalog/types.ts
@@ -25,6 +25,7 @@ export interface IDbProjectCatalog {
   evaluatedAt: string | null
   onboardedAt: string | null
   onboardingError: string | null
+  skipReason: string | null
   syncedAt: string | null
   createdAt: string | null
   updatedAt: string | null
@@ -41,6 +42,7 @@ type ProjectCatalogWritable = Pick<
   | 'evaluationResult'
   | 'evaluationReason'
   | 'onboardingError'
+  | 'skipReason'
 >
 
 export type IDbProjectCatalogCreate = Omit<
@@ -51,6 +53,7 @@ export type IDbProjectCatalogCreate = Omit<
   | 'evaluationResult'
   | 'evaluationReason'
   | 'onboardingError'
+  | 'skipReason'
 > & {
   source?: string | null
   action?: ProjectCatalogAction
@@ -58,6 +61,7 @@ export type IDbProjectCatalogCreate = Omit<
   evaluationResult?: string | null
   evaluationReason?: string | null
   onboardingError?: string | null
+  skipReason?: string | null
 }
 
 export type IDbProjectCatalogUpdate = Partial<ProjectCatalogWritable> & {