Evals Are Tests Wearing a Lab Coat

June 29, 2026 · 11 min read

An eval is a test: a named scenario, an assertion, a verdict. The eval-tooling wave rebuilt the BDD coordination tax as golden datasets owned by a separate role. The eval suite should be the test suite, in domain language, with builders.

TDDAI AgentsTest DesignSoftware Delivery

Examples Pin Intent. Properties Pin the Invariants.

June 22, 2026 · 16 min read

Example-based tests anchor scenarios in the team's vocabulary. Property-based tests anchor invariants across the input space. The agent needs both axes, and most suites only carry one.

TDDAI AgentsProperty-Based TestingTest Design

Characterization Tests Are How Agents Enter Legacy Code

June 15, 2026 · 11 min read

Most code an agent is asked to change is legacy: large, under-tested, its behavior known only by what production does. An agent changing untested code is changing code with no specification. Characterization tests pin what the code does before anyone decides what it should do, and they are the on-ramp that makes the untested parts of a codebase safe to hand to an agent.

TDDAI AgentsLegacy CodeTest Design

World-Building Is the Test Discipline Agents Need

June 8, 2026 · 11 min read

A scenario factory is not setup convenience. It is a world-modeling language, and the layered grammar of object mothers, builders, and factories is the composition primitive agents recombine. Teams that hand-assemble setup hand agents nothing to build worlds from.

TDDTest DesignAI AgentsSoftware Craft
The PR Is Eating Itself · Part 2 / 2

What 'Senior' Means When Typing Is Free

June 1, 2026 · 16 min read

The traits the industry credentialed as senior, typing fluency and framework recall and syntax intuition, were proxies. The actual senior skill was always naming the right problem and shaping the seams that make it solvable. Agents made the proxies free; the actual skill is now visible.

AI AgentsSoftware CraftEngineering CareerTeam Topologies

Coverage Was a Proxy. The Proxy Just Failed.

May 25, 2026 · 16 min read

Coverage measured execution, not verification. Agent-generated tests pass coverage gates while writing assertions that pass even when behavior breaks. Mutation score is the metric coverage was always pretending to be.

TDDAI AgentsTest DesignMutation Testing
The PR Is Eating Itself · Part 1 / 2

Where the Review Point Moved

May 18, 2026 · 14 min read

Code review was always a weak proxy for design review. When agents write the implementation, the review surface migrates upstream to test names, builder APIs, and contract assertions. The diff is downstream of all three.

Code ReviewAI AgentsTDDSoftware Delivery

Just-in-Time Tests Are What You Get When You Gave Up

May 11, 2026 · 14 min read

Disposable tests catch this PR's regression and contribute zero to the next one. The persistent suite is a vocabulary, a contract layer, and a 10-year asset. JIT testing is a hospice plan for teams whose suites stopped compounding.

TDDAI AgentsTest DesignSoftware Craft

Agents Should Do TDD: For the Same Reason You Should Have

April 26, 2026 · 15 min read

TDD's value was never that a human ran the loop. The value was the loop itself: a constrained search procedure that converges on code that is correct, named for intent, and shaped to change. Strip the human out and the discipline still works for the same reasons.

TDDAI AgentsSoftware CraftTest Design
TDD in the Agentic Era · Part 3 / 3

The Bar for TDD Just Moved

April 14, 2026 · 9 min read

Agentic coding changes what 'good tests' means. The new floor is scenario-rich, builder-driven, domain-typed tests authored by product-thinking developers, because that's the artifact agents actually compose against.

TDDAI AgentsSoftware CraftTest Design
TDD in the Agentic Era · Part 2 / 3

BDD Was a Coordination Tax. AI Just Repriced It

April 7, 2026 · 11 min read

Gherkin was never really a test format. It was a coordination protocol between specialized roles. In the AI era, where roles compress and translation is cheap, the protocol becomes friction instead of leverage.

BDDAITeam TopologiesSoftware Delivery
TDD in the Agentic Era · Part 1 / 3

TDD Already Does BDD, Without the Gherkin

March 24, 2026 · 8 min read

BDD wasn't a discovery. It was a rebrand of what disciplined TDD was already doing. Test data builders, factory hierarchies, and mock-driven collaboration tests are the scenarios, and they evolve alongside the code instead of rotting beside it.

TDDBDDTest DesignSoftware Craft

Katas Are Rehearsal, Not Performance

February 28, 2026 · 3 min read

You don't practice TDD on production code. You practice on katas and bring the muscle memory to production. The gap between knowing TDD and doing TDD is reps.

TDDKatasPracticeSoftware Craft

Your Test Suite Is Your API for Agents

February 15, 2026 · 3 min read

Documentation lies. Wikis rot. READMEs drift. Your test suite is the only specification that stays current, and it's the interface AI agents actually use.

TDDAI AgentsSoftware ArchitectureAutomation

AI Agents Need Test Suites, Not Code Reviewers

February 1, 2026 · 3 min read

Autonomous AI agents can plan, implement, and deliver code. But without automated verification, you're just producing unreviewed changes faster. TDD provides the feedback loop agents actually need.

TDDAI AgentsAutomationDevOps

TDD Is Scaffolding for AI, Not a Speed Bump

January 1, 2026 · 3 min read

AI generates code fast. But speed without verification is just higher-velocity guessing. TDD provides the specification layer that makes AI-generated code trustworthy.

TDDAIAutomationSoftware Delivery