Notesfromthework

A pragmatic decision guide for early-stage B2B SaaS teams choosing between shared-schema, schema-per-tenant, and database-per-tenant data models. Includes a default that survives the first hundred customers, the five markers that should push you to isolate, and how to design today so the migration is cheap when it comes.

A practitioner template for integration specs that force decisions before code is written — idempotency, retry semantics, payload contracts, error taxonomy, and the observability hooks that make partner blame games short.

A walkthrough of an INP rescue on a production B2B dashboard. The profiling we used, the four interactions that were dragging the 75th percentile into the red, and the React 18 and architectural fixes — useDeferredValue, transitions, event delegation, virtualisation, hydration boundaries — that moved the app from failing to passing.

Production-tested data-fetching patterns for React Server Components in Next.js 15: request memoization, parallel awaits, streaming with Suspense, the new `use cache` directive, and where Server Actions actually beat Route Handlers.

An opinionated build vs buy decision framework for CTOs at 50-300 person B2B companies. Score strategic importance, differentiation, five-year total cost, and team capacity, with a worked example for a 120-person operations system.

Slowness is usually one of three problems, and teams misdiagnose the expensive one. A diagnostic framework for web applications that have quietly decayed.

AI writes a large share of new code in 2026, but developer trust has dropped to 29%. The real shift is not speed, it is verification. What the data says.

Build-vs-buy is the wrong question for most growing teams. Here is the decision framework we use, and when custom is honestly the right call.