Zohaib S.

I build, fix and maintain backend systems that carry real production load. 5+ years on Node.js and TypeScript services: third-party API integrations, data pipelines running 500K–1M events a day, and the reporting layers businesses make decisions on. My work has mostly been on systems that already existed and already had users. I'm comfortable inheriting a codebase, working out why it behaves the way it does, and changing it without breaking what works. That's largely been one long engagement owning the data infrastructure behind a performance marketing platform: 10 ad platform and 3 feed provider integrations, a ClickHouse reporting layer, and the services moving data between them. If you have a backend that needs to be faster, more reliable, or that nobody on your team fully understands anymore, send me what you're working with. REPRESENTATIVE WORK - Integrated ClickHouse as a reporting store for 100K+ row reports, cutting load time by 80%. - Traced a CPU spike to LevelDB compaction pressure from millions of individual writes, and reworked the ingestion path to batched commits on a 1s interval. - Rebuilt an API's authorization layer around a Redis-backed user tier and status model, replacing static config-file access control, with a permissions API alongside it. WHAT I CAN HELP WITH - Node.js and TypeScript backends (NestJS, Express) - Third-party API integrations, including undocumented and rate-limited ones - OAuth and platform auth integrations: YouTube, Meta, TikTok - Multi-tenant architecture: organization scoping, data isolation, retrofitting tenancy onto single-tenant systems - Database performance: PostgreSQL, ClickHouse, Redis, query and schema optimization - Data pipelines, ETL and reporting infrastructure - Reliable background processing: idempotent retries, crash recovery, exactly-once publishing (BullMQ, Redis) - Production debugging: memory leaks, CPU spikes, latency regressions - Deployment on GCP: Compute Engine, Cloud Storage, Artifact Registry, Docker, CI/CD TECHNOLOGIES Node.js, TypeScript, JavaScript, NestJS, Express, REST APIs, GraphQL, WebSockets, JWT, OAuth 2.0, PostgreSQL, Prisma, ClickHouse, Redis, MongoDB, MySQL, LevelDB, BullMQ, Docker, microservices, GCP (Compute Engine, Cloud Storage, Artifact Registry, Cloud Build, Cloud Logging), AWS, CI/CD, GitHub Actions, Vitest, Jest, Git, Meta Graph API (Marketing, Instagram), YouTube Data API, TikTok API, ETL, data pipelines, performance optimization, API integration