Hi, I'm Sayan.
I'm a software engineer based in Kolkata, India, currently leading engineering for a mobility platform operating in 400+ cities. I work across the whole stack — APIs, frontends, and the infrastructure underneath — but I'm happiest in the unglamorous middle of a system: the queues, the pricing engines, the rate limiters, the parts that have to be right every single time.
Before that, I co-founded an EdTech platform from scratch — React frontend, Node.js backend, database, and deployment — which taught me that shipping fast and building something that lasts aren't actually in tension — you just have to be honest about which one matters more, when.
Career
Senior Backend Engineer & Tech Lead
Drivado — Chauffeur & Mobility Platform- Led backend architecture and a 15+ engineer cross-functional team for a global chauffeur and mobility platform operating across 400+ cities.
- Built an LLM-powered location normalization service using OpenAI, Mapbox, and LangSmith, reducing manual location searches from 50% of bookings to 1–2%.
- Improved booking performance by 3× (speed of booking conversion from search) and user engagement by 2× through backend optimization, 70% faster search, Redis caching, and automated billing, invoicing, and payment flows.
- Migrated booking workflows from Redis Pub/Sub to Kafka to reliably process 300K+ daily events, retain event history, and enable consumption across multiple services.
- Designed a zone-based pricing engine using polygon matching and layered rules for markups, discounts, and night/event charges, delivering pricing under 700ms.
- Owned production infrastructure with Docker, Kubernetes, NGINX, and GitHub Actions, reducing infrastructure costs by 53% while supporting 500+ RPS.
- Hardened payment APIs with Cloudflare WAF to support PCI DSS compliance.
Founding Engineer
Rising Leafs — EdTech Platform (WEBEL-BCC&I)- Co-founded and built a role-based learning platform using Node.js, Express, React, and MongoDB, onboarding 500+ users.
- Redesigned backend APIs and frontend workflows, increasing platform engagement by 30%.
How I work
Ship measured, not guessed
Every optimization I make is backed by a number — latency, cost, or load — not a hunch about what feels slow.
Systems that scale before they have to
I design for the load you'll have in a year, not just the load you have today — without over-building for a future that never comes.
Clear communication over clever code
Leading 15+ engineers taught me that a system only scales as well as the team's shared understanding of it.
Open to full-time roles and freelance work.
Have something in mind, or just want to say hello? I'd like to hear from you.