Trung Thi Phuong

Contributed as both a Software Engineer and Quality Engineer, developing billing engine and dashboard management services while implementing automated testing API for an LLM reseller SaaS platform serving 100+ enterprise clients.

• Owned the billing engine end-to-end: tiered pricing logic, idempotency guarantees, and retry-safe payment callback processing to prevent duplicate transaction updates.
• Optimized a Kafka-driven pricing and billing pipeline by introducing object pooling and reducing allocations by 84%, improving throughput 4x while lowering p95 latency from 450ms to 180ms
• Shipped an LLM agent CLI bridge in one day, enabling AI agents to call platform APIs directly without a UI — improving developer and agent-first onboarding.
• Collaborated with Engineers and QA teams to refine requirements, define acceptance criteria, and identify test scenarios before implementation, reducing downstream defects by approximately 80% and minimizing rework during testing phases.

Research solution architected and shipped a self-hosted E2EE real-time chat system for 1M users by Golang, PostgreSQL, NATS, Websocket

• Ensure zero third-party dependencies (no using FCM service), enforcing Forward Secrecy, Break-in Recovery, Pre-key Pool management, stateless message routing, and resistance to Pre-key Exhaustion attacks.
• Proposed and implemented a structured Research methodology (problem-first benchmarking that reduced team research and system design time by 90%, cut trial-and-error cost significantly, and improved overall system quality by 30% compared to the previous ad-hoc approach.
• Implement and Optimize strategy Distributed Logs offer confidentiality, integrity, availability for system
• Using Websocket to build a Chat Realtime system supports 100 users per group chat .
• Using Rate Limit and Last Resort" Pre-key to avoid Mitigating Pre-key Exhaustion Attack
• Optimized latency routing message through backend service p95/p99 by k6s 350ms → 200ms (−43%) with 1,000 req concurrency in 4ms on 4CPU/8GB .
• Collaborated cross-functionally with frontend, hardware, PM, and stake holder to design systems to meet government-grade security requirements Viettel Cyber Security audit (ISO/IEC standards).

• Integrated Keycloak OIDC/OAuth2 into 10 services, eliminating per-app authentication and reducing login friction for 100+ admin users
• Using NestJS and React management config TTS + Text-to-Video AI pipeline end-to-end support render and upload Youtube 1000 video/days
• Combine and Design and Implement RBAC support for all resource
• Shipped bulk-change UI eliminating N-step onboarding loop;
• Design optimization → 30% faster permission queries.

AI-first SDLC platform (Git, Agile, Jira, OKRs, AI Skills).
Trained 20+ engineers on outcome-first engineering practices.