GoKawiilIn early 2025, I wrote Is Claude a Compiler? At the time, my answer was: I don’t know.
I’m now pretty sure the answer is “no, that’s a category error, it’s better than a compiler.” But this requires a bit of unpacking.
Computer programs are notoriously intricate and finicky. A program operates at an extreme level of precision. There is no “wave hands” CPU instruction. High-level goals, meanwhile, are deeply underspecified.
In a highly stylized view of the world, software gets built in layers, each one adding specification and hiding “unnecessary” detail. Vision becomes strategy, product plans become coding plans, code becomes binaries. Each step is handled by a different role: executive, VP, PM, architect, engineer, compiler.
Critically, every step involves making lots of decisions. That’s what it means to increase the level of specification. (This is why one of my two key metrics for hiring engineers is judgment. The other is comity.)
The bottom layer, from source code to binary, is what a compiler does. Compilers make lots of decisions! Inlining, register allocation, whether to emit warnings or reject a program outright. And these decisions matter: They drive performance, system stability, predictability, and failure modes. A compiler engineer’s job is to arrange for the compiler to make consistently good decisions.
A good, trusted compiler frees a software engineer from having to make these decisions. Most engineers have little idea how compilers work; they don’t need to in order to be effective.
In 2025, we operated in a world where we used LLMs to generate smallish chunks of code. In this mental model, a coding agent might slot in as a new layer between a software engineer and a traditional compiler. It “compiles” natural language to code, making decisions so the engineer doesn’t have to. Its value is proportional to its reliability and the scale of the decisions it can make.
The thing is, this highly stylized view of the world is false. Abstractions leak and layers rub. And even if they didn’t, we’d poke holes in them anyway.
Working across layers is extremely valuable; mechanical sympathy matters.
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