Rubric for keeping Claude Code sessions cheap without losing quality — model tiering, cache hygiene, Read discipline, MCP pruning, subagent isolation. Use when cost feels wrong, before setting a budget, or when onboarding a teammate.
Safe schema-migration patterns for systems under live traffic — expand/contract, backfill, double-write, shadow-read, online DDL. Use when authoring, reviewing, or sequencing a migration that can't take a maintenance window.
What good observability looks like — structured logs, trace spans, metrics, correlation ids, and the instrumentation rules that turn logs into answers. Use when adding a feature, reviewing a service, or debugging a prod issue.
WCAG 2.2 AA quick reference — semantics, keyboard, names, states, contrast, motion, errors. Use when building or reviewing UI components.
REST and GraphQL API design conventions — resource modeling, pagination, error envelopes, versioning, idempotency. Use when adding, changing, or reviewing endpoints.
Apply the Write/Select/Compress/Isolate framework to manage the context window. Use when the task is long, the transcript is bloated, the model is drifting, or before /holocron:handoff.
Hypothesis-driven debugging — reproduce, hypothesize, probe, locate, fix, guard. Use when something is broken and you don't yet know why.
Performance quick reference — Core Web Vitals, bundle size, rendering, DB queries, caching. Use during implementation or review when perf matters.