Add "AI is backfilling your tests, and it's a regression" post#16
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# Problem AI agents default to writing tests after the implementation is already done, backfilling assertions against code that exists rather than designing against code that doesn't yet. This quietly breaks the red-green-refactor cycle and turns a green test suite into a formality instead of a verdict. # Solution New engineering post arguing that TDD's real value was never the tests themselves but the design step that writing a test first forces you through. The post traces how AI erodes that discipline by default, then describes how the Oracle (the team's contextual code review knowledge base) identified the pattern and now instructs agents to write failing tests before writing any implementation. The constraint that makes TDD valuable for humans turns out to make it valuable for agents for exactly the same reason: committing to an interface before committing to an implementation shapes better architecture. Adds the markdown source, the generated HTML, index listing entries on both the home page and the engineering index, a new sitemap entry, and updated lastmod timestamps. # Notes Sitemap lastmod for the root and engineering index pages bumped to 2026-06-24 as part of the build output.
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Problem
AI agents default to writing tests after the implementation is already done, backfilling assertions against code that exists rather than designing against code that doesn't yet. This quietly breaks the red-green-refactor cycle and turns a green test suite into a formality instead of a verdict.
Solution
New engineering post arguing that TDD's real value was never the tests themselves but the design step that writing a test first forces you through. The post traces how AI erodes that discipline by default, then describes how the Oracle (the team's contextual code review knowledge base) identified the pattern and now instructs agents to write failing tests before writing any implementation. The constraint that makes TDD valuable for humans turns out to make it valuable for agents for exactly the same reason: committing to an interface before committing to an implementation shapes better architecture.
Adds the markdown source, the generated HTML, index listing entries on both the home page and the engineering index, a new sitemap entry, and updated lastmod timestamps.
Notes
Sitemap lastmod for the root and engineering index pages bumped to 2026-06-24 as part of the build output.