Summary
Backend developer on Node, PostgreSQL, and Redis for Islamabad SaaS teams. Five years building REST APIs, payment webhooks, and migration scripts. p95 latency under 180ms across 12 production apps after index and cache work.
Projects
Invoice Reminder Service
Cron + email nudges for retailers; 3,000 invoices/month, 12% faster collections (client reported).
github.com/rafayhashmi/invoice-nudge
Webhook Replay Worker
Dead-letter queue for failed payment callbacks; open-sourced after internal use.
github.com/rafayhashmi/webhook-replay
Experience
Backend Developer
Feb 2021 to Present
CodeUnit Islamabad
- REST APIs for 12 client apps; p95 latency under 180ms after index tuning and Redis caching.
- 900GB Postgres migration with 38 minutes downtime; checksum validation on 240 tables.
- Payment webhook retry queue cut failed settlements 41%; on-call runbooks for JazzCash and Stripe flows.
- Auth service rewrite (JWT + refresh rotation); session-related support tickets down 55%.
Junior Developer
2019 to 2021
Freelance / Upwork
- CRUD apps for inventory and booking; 6 delivered projects, 4.9 average client rating.
- Docker Compose deployments on Hetzner VPS; basic CI with GitHub Actions.