Building a Payments Portfolio That Gets You Hired
Build these 5 projects: 1) Basic Paystack checkout with webhook handler and idempotency. 2) Subscription billing system with dunning logic. 3) Marketplace with subaccount split payments. 4) Payout system with transfer approval workflow. 5) A webhook HMAC validator with test suite. Document each with: architecture decisions, security choices, test coverage %, and a live demo link.
The Five Portfolio Projects
| Project | What It Demonstrates | Complexity |
|---|---|---|
| Simple checkout + webhook handler | Basic API integration, HMAC validation, idempotency, order fulfillment | Beginner |
| Subscription billing with dunning | Paystack Plans, invoice.payment_failed handling, retry logic, subscription lifecycle | Intermediate |
| Marketplace with split payments | Subaccounts, bearer configuration, multi-vendor payout | Intermediate |
| Payout system with approval workflow | Transfer API, dual-approval, batch transfers, transfer.failed retry | Advanced |
| M-Pesa + Paystack dual checkout | Multiple payment methods, STK push, webhook routing by method | Advanced |
What to Document in Each Project
For each portfolio project, your README should answer:
- What the system does — one paragraph, business use case, not just technical description.
- Architecture diagram — even a simple boxes-and-arrows showing: client, server, Paystack, database, webhook processor.
- Security choices — "Webhook signatures validated with HMAC-SHA512. Secret key in environment variable. No card data stored."
- Test coverage — "85% line coverage. Unit tests: webhook signature validation, idempotency check. Integration tests: full charge.success flow against Paystack test mode."
- Edge cases handled — "Duplicate webhook events are idempotent. Network timeout on verify results in a retry with exponential backoff."
- Live demo link — deploy to Vercel/Railway/Render with Paystack test mode keys.
Start Building
See portfolio project walkthroughs for step-by-step guides.
Key Takeaways
- ✓Employers want to see webhook handling and idempotency — not just a working checkout.
- ✓Include your test coverage percentage and what you tested for in each portfolio project.
- ✓Document security decisions: how you store keys, how you validate webhooks, what you log.
- ✓A live demo + GitHub repo with a README beats a screenshot-only portfolio.
- ✓Five focused payment projects beat twenty general projects for fintech hiring.
Frequently Asked Questions
- Should portfolio payment projects use test mode or live mode?
- Always use test mode for portfolio projects. Use Paystack test keys and test card 4084084084084081. Never hardcode test keys in your repo — use environment variables even for test keys. A recruiter or client reviewing your code who sees sk_test_... in a .env file is fine; seeing it hardcoded in source is a red flag.
- How long should I spend on each portfolio project?
- A well-built simple checkout with webhook handler: 2-3 days. A subscription system: 1 week. A marketplace with split payments: 1-2 weeks. Do not rush to add features — spend the extra time writing tests and documentation. A minimal, well-tested, well-documented project is more impressive than a large, poorly-documented one.
- Do I need to include a frontend in each project?
- For client-facing portfolio projects, yes — a minimal HTML/React frontend that shows the checkout flow improves the demo. For an API-only project (like a payout system), a Postman collection or curl examples in the README are sufficient. Interviewers at product companies want to see the full flow; API-focused companies care more about the backend and tests.
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