Senior Software Engineer – Backend — Vegapay
B2B credit card and lending infrastructure for banks and fintechs. Joined as the 11th employee; company now 135+.
- Designed and built the core Credit Card Management System (CMS) and the Credit Line on UPI platform before the team scaled; it now handles 1M+ transactions/day and INR 1,344 Cr+ lifetime volume.
- Owned the Unity × BharatPe RuPay credit card backend end-to-end: issuance, ISO 8583 authorization (including international transactions), limits, EMI engine, and double-entry ledger.
- Technical point of contact for Unity Bank and BharatPe through the card go-live; also integrated Credit Line on UPI programs for SSFB × Paytm and YBL × BharatPe.
- Run 12 production microservices at 99.99% availability and a 99.99% transaction success rate, with P99 authorization latency under 150ms.
- Banks were escalating duplicate and silently dropped transactions: made APIs and Kafka consumers idempotent (DB unique constraints) and added retries, DLQ, and alerts, cutting escalations 70%.
- To stop losing events during Kafka outages, designed a transactional outbox: events are saved in the same DB transaction as the business change, then published and replayed after recovery.
- Cut P99 latency 65% and P50 40% on the Block Code (card risk control), transaction, and bill services using Redis cache-aside, fewer redundant calls, and async Kafka steps.
- Mentor 4–5 engineers; guided and reviewed their delinquency and collections module (INR 29 Cr+ collected); helped raise unit test coverage to 80%+.