Kulazhenko P.

I build and fix Node.js backends that stay fast under real load - APIs, payment flows, third-party integrations, and background jobs. Recent results: cut an orders API from ~30s to ~1s, and reduced a service's memory footprint 100x while scaling its output from 24 to at least 15,000 rows. Over 6+ years I've shipped backend systems for e-commerce, SaaS, EdTech, and trading platforms, usually as an autonomous engineer trusted with architecture decisions. I work with NestJS, Express, Fastify, PostgreSQL, Redis, RabbitMQ/NATS/BullMQ, and AWS, and I keep test coverage high (80%+ on my last long-term project) so things don't break after I hand off. What I can help you with: building or extending REST/gRPC APIs, integrating payment gateways, Zoom, exchange APIs and other third-party services, untangling slow queries and memory issues, setting up event-driven flows and job queues, and improving reliability of existing Node.js codebases.