Xiaohui Chen

I’m a Senior Software Engineer with 10 years of experience building high-throughput subscription and billing platforms in Go and full-stack TypeScript. I design Go gRPC microservices, Stripe-backed billing state machines, and event-sourced systems that gate and bill access for platforms serving millions of subscribers.

At DoorDash, I revamped a Go billing backend with Stripe Payment Intents, a grace-period state machine, PostgreSQL event logging, and a concurrent retry scheduler—cutting involuntary subscriber churn by ~20% and reducing p99 latency from 180ms to 60ms. I also re-architected a Go gRPC eligibility microservice with denormalized PostgreSQL models, PgBouncer pooling, and Kafka-driven Redis cache invalidation to bring p99 eligibility latency down to 60ms.

I ship end-to-end product functionality: I delivered the DashPass for Teams portal in Next.js SSR and built the consumer home feed in React/TypeScript, backed by a NestJS provisioning API with Stripe B2B subscription schedules and idempotent webhook handling. I operationalized lifecycle event streaming with Kafka and Flink consumers writing to Redshift and Redis, standardizing OpenTelemetry, Prometheus, and Grafana SLO dashboards across subscription workflows.

Earlier at Amazon, I hardened Prime membership conversion services in Node.js with DynamoDB conditional writes for idempotency and scaled Sponsored Products retrieval with Java Spring Boot and Elasticsearch, sustaining sub-100ms p99 during peak traffic. I also advanced applied ML by integrating a transformer-based ad-copy quality classifier on SageMaker via a Python sidecar, reducing manual review volume by ~30%.