Our API receives GitHub webhooks and creates a subscription for each event. GitHub retries when we respond slowly, so we now have duplicate subscription records and double emails. I need signature verification checked, an idempotency key stored, the work moved to a background job so we answer quickly, and a one-off script to find and merge the existing duplicates.

Customers are being charged or notified twice and finance has to correct it by hand.

Key Deliverables:

• Codebase Review & Initial Implementation: Reviewing existing code, setting up development environment, and beginning core work.

• Feature Implementation & Testing: Completing primary deliverables with automated and manual testing.

• QA Verification & Production Deployment: Final cross-browser/device testing, staging verification, and production handoff.

Requirements:

• Demonstrated experience with Node.js, REST API, PostgreSQL, Webhooks, Idempotency

• Quick turnaround needed — must be available to start within 24 hours.

• Must test on both mobile and desktop before requesting milestone release.

If you have experience with this type of project, we'd love to hear from you. Please include relevant work samples with your bid.