Backend / Fullstack Developer · Ho Chi Minh City
I build web systems from requirement analysis, APIs and service integrations to deployment, measurement and production troubleshooting. My focus is Laravel, Redis, payment webhooks and RAG architecture.
6.1× is from a controlled 25-VU benchmark, not a production SLA.
Professional experience
Apr 2024 — Present
MyAloha Technology JSC · Ho Chi Minh City
Build and operate competition and online-exam systems with Laravel and Vue/Nuxt. Key ownership includes Redis runtime and ranking, data exports, Casso webhook extensions, ZNS/invoice/Lark integrations, VPS deployment automation and technical direction for a RAG chatbot.
Oct 2023 — Dec 2023
Hybrid Technologies Vietnam · Ho Chi Minh City
Worked in a three-person Agile team on an end-to-end Laravel application: requirements, database design, development, testing and deployment. Standardized the environment with Docker and GitLab workflows.
Selected work
Moved exam sessions to Redis Hashes, autosaved by field, prevented duplicate creation with distributed locks and queued persistence to S3 outside the hot path.
At 25 VUs, throughput improved by about 6.1×; getQuestions p95 dropped 69% and save p95 dropped 70% versus the S3-first flow.
Encoded score and submission time, used Lua for atomic ZSET and metadata writes, HyperLogLog for participant estimates, and a MySQL rebuild job.
O(log n) rank lookups reduced reliance on expensive MySQL sorting for the hot ranking flow.
Extended an existing flow with secure-token validation, transaction-code parsing, amount checks and events for notifications, invoices and synchronization.
Extended and operated the post-payment flow in a live system; I do not claim the original core endpoint.
Directed a pipeline covering normalization, rule-based safety, rewriting, metadata schema, hybrid retrieval, LLM and SSE with tenant isolation and controlled fallbacks.
Owned technical planning and architecture review; the team implemented the agreed direction.
Technical capabilities
PHP, Laravel, REST APIs, webhooks, queues/jobs, events/listeners, and supporting work with Python Flask/FastAPI.
MySQL, Redis Hash/ZSET/Lua/HLL, caching, transactions, indexing and Elasticsearch integration.
LLM integration, embeddings, hybrid retrieval, prompt/safety, SSE and multi-tenant chatbot design.
Vue.js, Nuxt.js, Inertia.js, Tailwind CSS and JavaScript/TypeScript.
Linux, Bash, Nginx, PHP-FPM, Docker, Horizon/Supervisor, k6, Grafana, GitLab CI/CD and SSH automation.
Casso, Zalo ZNS/OA, Zalo Mini App, Viettel S-Invoice, Lark and Google Apps Script/Drive/Docs.
Education
Engineer in Information Technology · Jul 2023
Certificate
06/2023
Contact
Backend/Fullstack Developer focused on Laravel, Redis and reliable production systems. Open to backend and fullstack opportunities.
ng.hongkhanh84@gmail.com