On this Dead Code episode, Jared talks with Varun Gandhi, a Databricks engineer who works on Git performance for the company's monorepo. The topic is Varun's reply to Dan Luu's post "There's No Reason for Software to Be Slow Anymore," which argues that LLMs have made performance work cheap. Varun agrees the cost of learning and applying advanced techniques has dropped. His objection is that LLMs have also made it cheaper to ship buggy code, and a lower price doesn't change what teams prioritize. He adds that people now accept slower tools because agents run that work in the background. He also points out that writing the code is often the smaller cost compared with deployment, review, and preventing regressions. One example is Bun's fork of the Zig compiler, which was about four times faster but was rejected upstream partly because its type checking could give non-deterministic results. On DHH's prediction that by year's end every developer will treat the code as a black box, Varun doubts Rust rewrites are the answer for everyone, since the Go and Elixir versions came close once their obvious problems were fixed. His takeaway is that slow software has fewer excuses now, but because shipping suboptimal code is easier than ever, he expects to see more of it for a while.
Links:
There continue to be reasons for software to be slow (Varun Gandhi)
There's no reason for software to be slow anymore (Dan Luu)
Reviewing code is a skill (Varun Gandhi)
DHH's Rails World 2026 opening keynote
Bun's Zig fork got 4x faster compilation times (Ziggit discussion)
Varun's blog, typesanitizer.com
Dead Code Podcast Links:
Jared’s Links: