Notes

Thinking out loud about product, engineering, and the space in between.

~/notes · session 20263 entries

$catnotes/when-ai-makes-sense-in-product.md

2026-03-12·5 min

The 80/20 rule applied to AI: use deterministic rules for predictable problems, reserve ML for genuine judgment calls. Most features don't need a model.

#ai #architecture

$catnotes/managing-payments-at-scale.md

2026-03-01·6 min

Managing payments at scale

Payments require a different PM mindset. Safety before possibility. One week reading the API and tracing money flows prevents months of production fires.

#payments #architecture

$catnotes/build-vs-buy-framework.md

2026-01-18·4 min

Build vs Buy framework

Build vs buy is four strategic questions in sequence, not a technical one: constraint, differentiator, total cost, reversibility.

#architecture #metrics

If you want to see the reasoning applied to real products, the case studies have the details.

See the workEmail me