On two greenfield web apps using straightforward stuff (Preact, Go, PostgreSQL) Claude Code has been very helpful. Especially with Claude Code and Opus >= 4.5, adding an incremental feature mostly just works. One of these is sort of a weird IDE, and Opus even does OK with obscureish things like CodeMirror grammars. I literally just write a little paragraph describing what I want, have it write the code and tests, give it a quick review, and 80% of the time it’s like, great, no notes.

To be clear, this is not vibecoding. I have a strong sense of the architecture I want, and explicitly keep Claude on the desired path much like I would a junior programmer. I also insist on sensible unit and E2E test coverage with every incremental commit.

I will say that after several months of this the signalling between UI components is getting a bit spaghettilike, but that would’ve happened anyway, and I bet Claude will be good at restructuring it when I get around to that.

I also work in a giant Rails monolith with 15 years of accumulated cruft. In that area, I don’t write a whole lot, but CC Opus 4.6 is fantastic for reading the code. Like, ask “what are all the ways you can authenticate an API endpoint?” and it churns away for 5 minutes and writes a nice summary of all four that it found, what uses them, where they’re implemented, etc.