LowFile-scopeKotlin Plug & play

Use map lookups instead of iteration

Prefer direct Map access over linear scans when looking up by key.

Why this matters

Reduces complexity from O(n) to O(1) average and simplifies code.

Side-by-side examples engineers can pattern-match during review.

Avoid

var v: Int? = null
for ((k, value) in map) if (k == id) v = value

Prefer

val v = map[id]

Bad

list.find { it.first == k }?.second

Good

map[k]

From the same buckets as this rule.

Critical
Avoid Blocking Calls to Async Methods
Blocking async methods with `.Result` or `.Wait()` can cause deadlocks and prevent efficient asynchronous execution. Use `await` instead for proper async behavior.
concurrency-safetyperformance-efficiency
Critical
Fingerprint assets and cache immutably
All static JS/CSS/font/image files MUST use content-hashed filenames (e.g., app.9c1a7b.js) and be served with "Cache-Control: public, max-age=31536000, immutable". HTML and other non-fingerprinted documents MUST be served with "Cache-Control: no-cache" (or equivalent) to enable conditional revalidation.
web-static-assetscaching-strategy+2
Critical
No live network or DB in unit tests—use fakes/mocks
Unit tests must stub or fake external HTTP/DB calls; allow real I/O only in integration/e2e tests tagged accordingly.
testing-qualityperformance-efficiency+1