“EN-09-Full-Stack-Project-Implementation”

Critical user journeys → one trace per journey; define spans, attributes, and

Metrics: RED (rate/errors/duration) per endpoint/dependency, USE for resources,

Logs: structured (JSON) schema with ts/level/trace_id/span_id/user_hash/

Alerts: SLO-based burn-rate alerts (multi-window), symptoms over causes,

Code instrumentation examples and tests asserting trace attributes and

Type Safety / Strict-Mode Enforcer

Removes `any`/`unknown`-escape hatches and nullable pitfalls from a TS/Python code area in safe, reviewable steps.

Inventory unsafety: any/as casts, non-null assertions, @ts-ignore, untyped

Rank by risk (external boundary types first). For each: model the real shape

For JSON/API responses, generate types from the OpenAPI/JSON schema instead of

Submit in small commits: enable stricter rule per directory, fix violations,

Pair-Programmer for an Unfamiliar Codebase

Onboarding/exploration prompt: builds an accurate mental model of unknown code, tracing one request end to end before changing anything.

Architecture in one page: entry points (server bootstrap, routes, CLI), request

Draw an ASCII diagram of components and data flow; mark module boundaries and

Conventions: how errors, config, auth, logging, tests, migrations, and feature

Glossary of domain terms as used in the code, and where the authoritative

"Where would I change X?" map for 5 common changes (add endpoint, add field,

Confusing/dead-looking areas and questions to ask the team — label your

Test-Coverage Gap Analyzer

Identifies untested critical paths (not line coverage) and writes the highest-value missing tests first.

Map behaviors (not lines) to tests: which business rules, branches, and

Rank gaps by risk: money/auth/data-loss/permissions > complex branching >