Engineering leader, AI builder. Writing about agents, evals, and the strange new shape of software.https://varunkumar.dev/en-ushttps://varunkumar.dev/writing/learning-was-never-about-information/https://varunkumar.dev/writing/learning-was-never-about-information/How AI is turning learning from a fixed curriculum into a personal journeyTue, 11 Aug 2026 09:00:00 GMThttps://varunkumar.dev/writing/owning-the-comments-section/https://varunkumar.dev/writing/owning-the-comments-section/I picked Giscus as a deliberate tradeoff when I built this blog. A few weeks later, reader friction changed the equation, so I replaced it with my own comments system.Fri, 24 Jul 2026 13:00:00 GMThttps://varunkumar.dev/writing/the-cost-of-a-hi/https://varunkumar.dev/writing/the-cost-of-a-hi/A full token breakdown for a first-turn Hi: the starting price of a model and a tool-search myth I believed for too long.Sun, 19 Jul 2026 02:00:00 GMThttps://varunkumar.dev/writing/building-a-blog-in-the-age-of-ai/https://varunkumar.dev/writing/building-a-blog-in-the-age-of-ai/After a decade away from blogging, this is how I finally removed the barriers to writing.Wed, 15 Jul 2026 15:30:00 GMThttps://varunkumar.dev/writing/giving-claude-a-distributed-memory/https://varunkumar.dev/writing/giving-claude-a-distributed-memory/Claude Code's memory is tied to a single machine. I built a Git-backed distributed memory so it remembers what it learns across all my machines.Wed, 08 Jul 2026 10:17:56 GMThttps://varunkumar.dev/writing/your-browser-is-an-ai-runtime-now/https://varunkumar.dev/writing/your-browser-is-an-ai-runtime-now/Chrome ships Gemini Nano directly into the browser, with no API keys or token cost. I am very excited about this and built three AI features on this site with it.Sun, 28 Jun 2026 17:17:56 GMThttps://varunkumar.dev/writing/the-story-of-a-stale-context/https://varunkumar.dev/writing/the-story-of-a-stale-context/A TOCTOU bug with a three-day window: how a frozen AI context silently overwrote a colleague's work, and the guardrails that prevent it.Mon, 04 May 2026 00:00:00 GMT