Feature Pod: Building a Webhook Delivery System

Scenario

A SaaS platform needs a webhook delivery system: users configure webhook URLs through a React dashboard, the Go API accepts and queues events, a delivery worker sends HTTP requests with retry logic, and the whole thing needs E2E tests. The API contract is well-defined: POST /webhooks, GET /webhooks, DELETE /webhooks/:id, and a delivery status endpoint.

Why This Topology

The feature spans three clear layers – backend API, frontend dashboard, and test suite – each of which can be built independently against a shared contract. Feature Pod lets each layer owner work in parallel after agreeing on the API shape, which is exactly how webhook systems are structured: the contract (event payload, delivery status codes) is the natural integration boundary.

Team Shape

Role Count Responsibility
Lead 1 Define contract, coordinate integration, final verification
Backend 1 Go API endpoints, delivery worker, retry logic
Frontend 1 React webhook config UI, delivery status dashboard
QA 1 E2E tests, edge cases, integration verification

Spawn Prompt

Create an agent team to build a webhook delivery system.
Spawn:
- Backend: Go API (CRUD endpoints + delivery worker with exponential backoff).
- Frontend: React dashboard (webhook config form + delivery status table).
- QA: E2E tests covering creation, delivery, retry, and failure scenarios.
First task: agree on the contract (API shape, event payload, status codes).
Then parallelize by layer. Reconverge for integration testing.

Trade-offs

  • The contract phase is the highest-leverage moment. Spend extra time specifying error cases and edge behaviors upfront – it saves rework during integration. Contracts can’t anticipate every edge case, but covering the obvious ones (e.g., what happens on deletion of in-flight items) prevents mid-build surprises.
  • QA should write edge-case tests early. Those tests function as a contract verification suite that catches specification gaps before integration. Don’t wait for the backend to be done.
  • Mock APIs enable true parallelism. If your contract is explicit enough to mock, it’s explicit enough to build against. The frontend can work completely independently using mock responses.
  • Integration is where gaps surface. No matter how good the contract, some edge cases only emerge when layers connect. Keep integration as a distinct phase rather than treating it as a formality.