Alexandre Parfonov

Full-stack Software Engineer @Devbrother

Vancouver, BC, CA

Stack: React.js, Node.js, Fastify.js, MongoDB, Redis, AWS (EC2, S3)- Building Node.js/Fastify.js RESTful APIs with middleware for authentication, rate limiting, and error handling, reducing response time by 30% to 150ms- Designing MongoDB time-series collections with TTL indexes and sharding strategy for consumption data, handling 10K writes/second with 40% better query performance- Implementing Redis streams with consumer groups for real-time data processing and event-driven alerts, decreasing alert latency from 10s to 4s- Developing billing calculation engine with cron jobs executing complex tariff algorithms and generating invoices for 3K+ customers with 99.8% accuracy;