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Examples/Marketplace

Course marketplace (example)

Instructors upload video courses, students buy them, and instructors get monthly payouts. Built with Next.js, a Node API, Postgres, Stripe Connect, S3 with Mux for video, and Meilisearch for search. Replace any part with how your own system works.

Scale: 40k students, 1,200 instructors, 5 purchases/min

12345678910111213CLIENTNext.js web appSERVICENode APIDATABASEPostgresDATABASEMeilisearchEXTERNALStripe ConnectOBJECT STORES3 video storageEXTERNALMuxEDGECDNQUEUEJob queueWORKERCourse worker

Select a component to see what it is responsible for and which state it owns.

  1. 1Next.js web app → Node API: Browse and buy
  2. 2Node API → Meilisearch: Search courses
  3. 3Node API → Stripe Connect: Create checkout
  4. 4Stripe Connect → Node API: Payment webhooks
  5. 5Node API → Postgres: Write orders and enrolments
  6. 6Next.js web app → S3 video storage: Upload via presigned URL
  7. 7Node API → Job queue: Enqueue index, transcode and payout
  8. 8Course worker → Job queue: Claim jobs
  9. 9Course worker → Mux: Start transcode
  10. 10Mux → Node API: Asset ready webhook
  11. 11Course worker → Meilisearch: Reindex course
  12. 12Course worker → Stripe Connect: Monthly transfers
  13. 13Next.js web app → CDN: Stream lessons
  • Request / response
  • Asynchronous
  • Bulk data

Select a part to trace its flows.

  • Request / response
  • Asynchronous
  • Bulk data

Parts 10

Flows 13

  1. 1Next.js web app → Node APIBrowse and buyRequest / response
  2. 2Node API → MeilisearchSearch coursesRequest / response
  3. 3Node API → Stripe ConnectCreate checkoutRequest / response
  4. 4Stripe Connect → Node APIPayment webhooksAsynchronous
  5. 5Node API → PostgresWrite orders and enrolmentsRequest / response
  6. 6Next.js web app → S3 video storageUpload via presigned URLBulk data
  7. 7Node API → Job queueEnqueue index, transcode and payoutAsynchronous
  8. 8Course worker → Job queueClaim jobsRequest / response
  9. 9Course worker → MuxStart transcodeRequest / response
  10. 10Mux → Node APIAsset ready webhookAsynchronous
  11. 11Course worker → MeilisearchReindex courseRequest / response
  12. 12Course worker → Stripe ConnectMonthly transfersRequest / response
  13. 13Next.js web app → CDNStream lessonsRequest / response

Invariants 3

  • A student is enrolled only after payment succeeds

    Enrolment inserted in the transaction that marks the order paid, run only from the verified webhook; unique (order_id) makes redelivery a no-op.

    Kept by

  • Each instructor is paid once per period

    payouts unique (instructor_id, period); the Stripe transfer uses idempotency key = payout id.

    Kept by

  • Search results converge to the database

    Course changes write an outbox row; the worker reindexes from it; a nightly full reindex repairs drift.

    Kept by