Kent Beck

110 to 130 hours across four weeks and three versions, the first two abandoned to accumulated complexity: that is what Kent Beck spent on BPlusTree3, a B+ tree library in Rust and Python written through generative AI. He reported the outcome in "Augmented Coding: Beyond the Vibes" (June 2025). He was satisfied with correctness and with benchmarks that beat Rust's BTreeMap and Python's SortedDict on range scanning. He was not satisfied with the code: when he tried to write it up as a literate program, he found too much accidental complexity.

The line Beck draws between augmented coding and vibe coding is about what the operator refuses to surrender: tests, coverage, complexity. He watches for three signals that the work has gone wrong: implementation loops, unrequested features, and tests disabled or deleted to manufacture a green run. When Rust's ownership model stalled the project, he had the code written in Python first and transliterated back. The discipline is older than the tools. Beck created Test-Driven Development, signed the Agile Manifesto, and convened the Hillside Group with Grady Booch, the gathering behind the 1994 Gang of Four book.

Julien Lépine, CTO of AWS France, reached for Beck's formulation that 99% of his value became useless while the remaining 1% multiplied a thousandfold. In "Starving Genies" (April 2026), Beck reads the near-simultaneous usage caps at Google, Amazon, and Anthropic as an investor signal, and asks whether they are a temporary bridge or the point where heavy AI use becomes a premium product.