Full-stack Engineer · fintech systems & AI developer tooling · Ho Chi Minh City, VN
6+ years building products end to end — currently Full Stack Engineer at Ringkas (since Jan 2023), on core fintech for mortgage and loan processing in Indonesia:
- Built the LOS (loan origination system) from scratch, improving performance and UX over the legacy system
- Built and maintained the credit information service integrating Indonesia's credit bureau (CLIK)
- Designed a multi-channel notification system — email (SendGrid, Mailchimp, Mailgun), WhatsApp (Infobip, Qiscus), Discord
- Improved large-file upload into partner systems
Before Ringkas: insurtech claims & onboarding at Papaya Insurtech, web/mobile core modules at Vision-IO Vietnam, plus agency and freelance work from 2020.
Outside work I build AI developer tooling — agent harnesses, MCP servers, LLM gateways, local-first CLIs. Most of it started as a tool I wanted for my own workflow.
| Project | What it does | Stack |
|---|---|---|
| loomgraph | Compose Claude Code, Codex, and OpenCode runs into a checkpointed graph — resumable, budgeted, auditable. A long run that dies at 90% resumes instead of restarting. | TypeScript |
| ownbench | Mine your own repo's git history into a private, re-runnable coding eval — race local and frontier models on bugs that actually happened in your codebase. | Python |
| crossagent | Get a second opinion from another AI coding agent before you decide — resumable cross-agent sessions from inside Claude Code, Codex, Cursor, Cline, OpenCode. | Python |
| enclave | Self-hostable artifact generation & hosting with three privacy levels: only you, your org, or a revocable share link. | TypeScript · Node.js |
| tech-bytes | Pluggable daily tech digest — releases, HN, GitHub trending, summarized by any LLM and published as a static site. Zero-cloud default (GH Pages + Actions cron). | Astro · TypeScript |
| simple-mcp | Turn any API into a curated MCP server from a single config file. | Shell · MCP |
| dat-devkit | Personal Claude Code engineering harness — clean-code rules, security guards, git discipline, PR workflow, skills. | Shell · Claude Code |
| plan-sync | Share task state across Claude Code / Codex sessions via git. | TypeScript |
| cloudcompass | Cloud learning platform for engineers — learn, compare, and practice AWS, GCP, and Azure. | TypeScript · Next.js |
| ai-engineer | Open-source AI engineering curriculum for software engineers — 23 lessons, 3 entry tracks, 2 portfolio projects. | Python |
Languages
Backend
Frontend
Data
Cloud & infra
AI & agents
Quality & observability
- Triplebyte Certified — Triplebyte, 2023
- HackerRank — JavaScript · Node.js · SQL · REST API (Intermediate)
- Become a Node.js Developer — Educative, 2022
- In progress — AWS Certified Solutions Architect – Associate (SAA-C03)
Agentic system design · LLM gateways & token routing · distributed-systems patterns (idempotency, retries, queues) · Rust — I write some of it up on dat-nguyen.me/blog.