sapsaldog's blog
Fragments of thought and traces of craft.
Full-stack DevOps generalist with 16+ years of experience. Founding Engineer at WeTrials, formerly Senior SWE at Mastercard. CS & Mechanical Engineering at Korea University. Published tech book translator and open-source contributor.
From Builder to Decision Maker
2026-04-20
Working with AI didn't just explode productivity — it exploded the volume of decisions, and that came back as a new kind of fatigue. An attempt to map the developer's new coordinate by borrowing the doctor·judge·lawyer quadrant, and to sketch the response: harness and scheduler.
Supabase doesn't support Naver as a provider. Custom OIDC failed due to Naver's non-standard API response. Here's how I solved it with an Edge Function proxy.
Promptfoo #2: TDD for Prompts
2026-03-15
Write failing tests first with Promptfoo eval, then fix your prompts to make them pass. TDD-style prompt engineering with a real Vision model debugging story.
Promptfoo, the LLM testing framework acquired by OpenAI. Prompt regression testing, model comparison, Red Teaming, and hands-on experience applying it to a real translation app.
Running OpenAI Symphony with Claude Code
2026-03-07
Forking OpenAI's coding agent orchestrator Symphony to add a Claude Code backend
Using a Git post-checkout hook to automatically copy .env files when creating worktrees
Setting Up CJK Fonts in Ghostty on macOS
2026-02-02
How to fix ugly fallback fonts for Korean (CJK) text in Ghostty by installing Noto Sans Mono CJK KR
Starting a Blog
2026-01-20
Why bother starting a blog in the age of AI