“Cold guardrail” resonates. I’ve been running guardrails only at slice boundaries as well. Deciding when interruption is justified has been surprisingly non-trivial.

Yes — that framing resonates a lot.

That shift from “does this work?” to “what breaks if this assumption is wrong?” is very close to what I’ve been circling around.

For me, the stall seems to happen when green tests stop reducing doubt and start just confirming structure. Integration-level tests sometimes help me reintroduce that pressure.

Really appreciate you articulating it so clearly.

Thanks — that’s a fair question, and probably on me for not being clear.

I’m not trying to replace design work with tests. What I’m experimenting with is using certain tests (especially integration-level ones) as a way to surface and challenge assumptions that feel stable on paper.

In other words, the tests aren’t the design, but they’re sometimes the fastest way I’ve found to discover where my “separate design step” was incomplete or misleading.

Happy to clarify more if helpful.