Selected work
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Bulk invoice import, rebuilt around COPY
I replaced a per-row ORM import with a reusable PostgreSQL COPY layer, cutting a large invoice import from about 3 hours to about 15 minutes.
3 h → 15 min~7,000 invoices, 50–100 lines each -
Inventory costing with safe stock and ledger writes
I rebuilt a weighted-average costing engine to run set-based in the background, and set the locking rules that keep stock and accounting rows consistent.
Off the request pathMatches accountants' reference results -
Background jobs on SQS and ECS that never run twice
I built a job platform on AWS SQS and ECS with atomic claims, leases, heartbeats, retries and idempotency keys, so long ERP jobs never run twice or vanish.
No double runsHeavy ERP work moved off the request path -
Multi-user QC batch updates without lost edits
Row locks plus version checks so several inspectors can edit one batch at once, safer login tokens, and a faster bulk update API.
~55% fewer queries~60% faster, local benchmark of ~320 rows -
Moving a live ERP API from App Runner to ECS
I built the deploy pipeline and AWS setup that moved a production Django API and its workers to ECS, with blue/green releases that roll back on their own.
Auto rollbackBlue/green releases, old platform retired -
Agent playbook: git gates that keep AI roles honest
An open-source rule and skill pack for AI coding agents. Git-level gates stop a tester, implementer or reviewer agent from changing files outside its role.
2,325 tests, 3 OSes165 commits, 17 tagged releases
More work
- Faster ledger, stock and sales reporting APIsTTMI · Retail ERP · 2025–2026
- A help portal whose build refuses wrong or leaky contentTTMI · Internal ERP help portal · 2026
- Money-safe finance data entry and spreadsheet exportsTTMI · Retail ERP · 2025–2026
- Session and access control across internal web appsTTMI · Internal web apps · 2025–2026
- A coverage check in CI that cannot be dilutedTTMI · Retail ERP platform · 2025–2026
- Scoped production exports for local debuggingTTMI · Retail ERP platform · 2025–2026
- FotoVerse: a collaborative photo-album appSide project · Photo sharing app · 2026
- HRM and KPI evaluation backend with role-scoped accessCloudJet · HRM and KPI platform · 2024–2025
About
I'm a software engineer in Ho Chi Minh City. I studied software engineering at UIT (VNU-HCMC), graduated with honors in 2026, and I'm now in its information systems master's program.
Most of my work sits where money and stock meet a database: making sure the number in a report matches what really happened in the store. I use AI coding agents every day, with my own open-source playbook of rules and skills, and I check what they produce with tests and review.
Outside work I build small tools for friends and keep my English sharp (TOEIC 965).