yanghau

Architected the backend and infrastructure for a real-time interactive video streaming product, optimizing for low latency and scalability. Built the core backend: real-time synchronization (WebSocket, gRPC), API layers, and crypto payments (Solana). Operated production on DigitalOcean using Docker Compose, Nginx, systemd, and CI/CD to standardize deployments and environments. Owned monitoring and on-call response with Prometheus and Grafana to maintain reliability and shorten incident resolution time.

Built quantitative trading bots and attack-mitigation systems to improve resilience of DeFi operations. Built a DeFi insurance platform that adjusted premiums using real-time on-chain risk signals across multiple assets.

Designed and built a notification scheduling system on GCP handling 1.3M+ daily requests for chatbot-driven marketing and in-chat commerce. Migrated from a monolith to microservices with Kubernetes and gRPC to improve modularity and fault isolation. Migrated from a relational database to a graph database (Dgraph), designing a production schema for flexible labeling and relationship queries. Integrated OpenTracing to improve observability and accelerate bottleneck diagnosis across distributed services.

Developed a secure messaging protocol using ECDSA and cryptographic primitives tailored for IoT constraints. Designed a proxy service that offloaded expensive crypto and blockchain operations for low-power IoT devices. Improved server throughput and latency by introducing RabbitMQ queuing and Redis caching. Built a Quorum-based Solidity system to make PostgreSQL-backed records auditable and tamper-resistant.