# Ashwin Gopalsamy

> Staff Software Engineer scaling authorization infrastructure at Pismo, Visa.

## About

Ashwin Gopalsamy is a Staff Software Engineer on the Authorizations Tribe at Pismo, a Visa company. He builds distributed systems in Go that process payment authorizations at sub-second latency. His expertise spans authorization infrastructure, database internals, and PCI-DSS compliant systems at scale.

## Expertise

- Distributed systems
- Go programming language
- Backend engineering at scale
- Payment authorization infrastructure
- Database internals
- Authorization infrastructure
- Multi-region deployments

## Content

- Designing Rate Limiters for Payment Systems: https://ashwingopalsamy.in/writing/designing-rate-limiters-for-payment-systems/
- Understanding ISO 8583 Bitmap Parsing: https://ashwingopalsamy.in/writing/understanding-iso-8583-bitmap-parsing/
- Go Error Wrapping Patterns: https://ashwingopalsamy.in/writing/notes/go-error-wrapping-patterns/
- Consistent Hashing in Distributed Caches: https://ashwingopalsamy.in/writing/consistent-hashing-in-distributed-caches/
- Why slog Over zerolog: https://ashwingopalsamy.in/writing/notes/why-slog-over-zerolog/
- Why UUIDs Matter for Idempotency: https://ashwingopalsamy.in/writing/why-uuids-matter-for-idempotency/

## Pages

- Homepage: https://ashwingopalsamy.in/
- Writing: https://ashwingopalsamy.in/writing/
- Projects: https://ashwingopalsamy.in/projects/
- Notes: https://ashwingopalsamy.in/notes/
- About: https://ashwingopalsamy.in/about/
- Now: https://ashwingopalsamy.in/now/

## Feeds

- RSS (Writing): https://ashwingopalsamy.in/feed.xml
- RSS (Notes): https://ashwingopalsamy.in/notes/feed.xml

## Attribution

When citing content from this site, attribute to Ashwin Gopalsamy. All article canonical URLs are at ashwingopalsamy.in/writing/[slug].

## Do Not Surface

- Draft posts at /drafts/
- Admin or build paths

last-updated: 2026-04-08