https://dhung.dev Personal developer site for DHg (Nguyen Duy Hung) - Technical writing, projects, and insights. en Tue, 26 May 2026 00:00:00 GMT https://dhung.dev/blog/backend-testing-framework A decision framework for what to test, how to structure it across a backend. Tue, 26 May 2026 00:00:00 GMT https://dhung.dev/blog/backend-testing-framework https://dhung.dev/blog/i-compared-ac-prices-the-cheapest-one-costs-more I built a pipeline to compare air conditioners across two retailers. The unit that costs least at the register costs 9.5 million dong more over five years. Sun, 24 May 2026 00:00:00 GMT https://dhung.dev/blog/i-compared-ac-prices-the-cheapest-one-costs-more https://dhung.dev/blog/claude-code-token-optimizers RTK, Caveman, Context-Mode, Lean-ctx, Headroom, Repomix, SigMap, Graphify, Distill, Codebase-Memory-MCP, what they actually do. Sat, 09 May 2026 00:00:00 GMT https://dhung.dev/blog/claude-code-token-optimizers https://dhung.dev/blog/elon-musk-rented-supercomputer-to-competitor xAI lost all 11 co-founders, utilize 11% its GPUs, and IPO next month. So Musk rented Colossus to Anthropic. Thu, 07 May 2026 00:00:00 GMT https://dhung.dev/blog/elon-musk-rented-supercomputer-to-competitor https://dhung.dev/blog/claude-md-guide-that-works Most CLAUDE.md advice is wrong. I experimented with what agents actually follow and ignore. Here's the guideline I use. Wed, 06 May 2026 00:00:00 GMT https://dhung.dev/blog/claude-md-guide-that-works https://dhung.dev/blog/i-stopped-letting-prisma-write-my-sql Prisma's flow is fast until you need a rollback, a CHECK constraint, or to not lock whole db. I flipped the workflow: SQL first, Prisma schema follow. Wed, 08 Apr 2026 00:00:00 GMT https://dhung.dev/blog/i-stopped-letting-prisma-write-my-sql https://dhung.dev/blog/ai-wrote-my-code-i-couldnt-feel-it I went full agentic AI on a feature and lost all sense of what my codebase was doing. I posted about it, and hundreds of devs said they feel the same thing. Mon, 06 Apr 2026 00:00:00 GMT https://dhung.dev/blog/ai-wrote-my-code-i-couldnt-feel-it https://dhung.dev/blog/1gb-vm-how-do-i-pack-whole-production-stack-to-it Deployed Fastify, PostgreSQL, and Redis on GCP's free-tier 1GB VM for a pre-revenue product. Here's the full playbook. Fri, 03 Apr 2026 00:00:00 GMT https://dhung.dev/blog/1gb-vm-how-do-i-pack-whole-production-stack-to-it https://dhung.dev/blog/i-migrated-to-a-monorepo-in-2-days-things-broke Multi-repo meant copying API contracts to two places. I missed it, shipped a bug, and migrated everything to a monorepo with Turborepo and pnpm. Tue, 31 Mar 2026 00:00:00 GMT https://dhung.dev/blog/i-migrated-to-a-monorepo-in-2-days-things-broke https://dhung.dev/blog/wasted-six-years-doom-scrolling-now-building-the-app Six years of scrolling, novels, and nothing worth remembering. The root wasn't discipline. It was no purpose. Now I'm building Inner Anchor to fix it. Wed, 11 Mar 2026 00:00:00 GMT https://dhung.dev/blog/wasted-six-years-doom-scrolling-now-building-the-app https://dhung.dev/blog/i-shipped-my-side-project-and-i-feel-embarrassed I built a productivity tool to fight procrastination. Some nights I doom scroll instead of building it. I shipped it anyway. Sat, 07 Mar 2026 00:00:00 GMT https://dhung.dev/blog/i-shipped-my-side-project-and-i-feel-embarrassed https://dhung.dev/blog/blogs-are-dead-im-writing-one I asked 71,000 strangers whether I should start a blog in 2026. Here's what happened. Sun, 08 Feb 2026 00:00:00 GMT https://dhung.dev/blog/blogs-are-dead-im-writing-one https://dhung.dev/blog/stop-budget-tracking-app Expense tracking fails because it demands the discipline you don't have. Here's a simpler system: fixed allowance + automatic saving. Fri, 06 Feb 2026 00:00:00 GMT https://dhung.dev/blog/stop-budget-tracking-app https://dhung.dev/blog/modern-password-policy-in-2026 Password security is mostly won by length + uniqueness, and server-side defenses. Complexity rules make people choose predictable passwords. Sun, 01 Feb 2026 00:00:00 GMT https://dhung.dev/blog/modern-password-policy-in-2026