Omar Haddad
Backend Developer — APIs, Databases, Scale
Toronto, ON · omarhaddad.dev · github.com/omarhaddad · linkedin.com/in/omarhaddad
Summary
Backend developer with 6 years designing services that stay fast under load. Shipped a gRPC service holding p99 at 35ms across 5K RPS, eliminated weekly database lock storms, and led a monolith-to-services migration with sub-30s cutover downtime. Strong in Go, Postgres, Redis, and event-driven design.
Skills
- LanguagesGo · Java · Python · Node.js
- DataPostgres · MySQL · Redis · MongoDB
- APIs & messaginggRPC · REST · GraphQL · Kafka · RabbitMQ
- ArchitectureMicroservices · event-driven · system design · observability
Experience
Backend Developer — Halcyon Payments
2021 — Present
Toronto, ON
- Designed and shipped a Go-based gRPC service exposing 14 endpoints to 8 internal teams; held p99 latency at 35ms across 5K RPS sustained.
- Re-modeled the orders schema to eliminate a hot row causing weekly Postgres lock storms, removing 12+ hours/quarter of paged on-call.
- Carved 4 services out of a monolith using the strangler pattern + a Kafka outbox; held cutover-window downtime under 30s for the auth domain.
- Added idempotency keys and dead-letter handling to the payments pipeline, cutting duplicate-charge incidents to zero.
Software Developer — Maple Systems
2018 — 2021
Ottawa, ON
- Built REST APIs for a logistics platform handling 1M+ daily requests.
- Introduced connection pooling and query caching, cutting average response time 30%.
Education
B.S. Computer Science — University of Waterloo
2014 — 2018