Justin Kong

• Improved scalability to 60+ msg/sec at 10 ms p95 across 4700+ events by implementing Kafka architecture. • Enabled observability with zero producer errors by integrating Prometheus metrics and Grafana dashboards. • Restored user sign-ins by debugging the authentication flow end-to-end and fixing the root-cause defect in the login/auth pipeline for a REST API. • Implemented Redis-backed token-bucket rate limiting with bounded queueing in an API gateway to smooth traffic spikes, prevent downstream overload, and mitigate abuse. • Added exponential backoff retries and circuit breakers for database connections to improve service reliability in partial outages, blocking 100% of failed requests and reducing retry storms by 97% under load testing. • Implemented a relational Prisma schema, enabling structured data flow and validated through successful migrations and API testing.