performance

Code splitting routes reduces initial bundle size and improves load times. React's lazy function dynamically imports components when routes are accessed. Wrapped in Suspense, lazy components show fallback UI while loading. I group related routes into

A per-request statement_timeout is a great “seatbelt” for endpoints that can run bad queries when parameters are unexpected. You can set it for a block; Postgres enforces the wall clock limit.

CSS transitions animate property changes with transition: property duration timing-function delay. I use transition-property to specify which properties animate. The timing-function controls acceleration with values like ease, ease-in, ease-out, cubic

rack-mini-profiler reveals performance bottlenecks in Rails apps. It displays database queries, rendering time, memory allocation on every page. I use Flamegraphs to visualize where time is spent. Memory profiling identifies allocation hotspots. Query

The only() method loads specified fields only, while defer() excludes specified fields. This reduces data transfer and memory usage. I use only() when I need just a few fields from large models. For read-only displays, this prevents loading unnecessar

Connection pooling reuses database connections instead of creating new ones per request. I use django-db-pool or configure persistent connections with CONN_MAX_AGE. This reduces connection overhead significantly. For high-traffic sites, I set appropri

Django Debug Toolbar reveals query counts, cache hits, and template rendering time. I add it only in development settings. The toolbar shows all SQL queries which helps identify N+1 problems. I use the profiler panel to find slow code. The cache panel

Turbo Frames can trigger lots of small requests, so caching matters. For expensive frame endpoints (like an activity panel), I use stale? with an ETag that includes a cache key and the latest update timestamp. If the content hasn’t changed, Rails retu

Prisma makes it easy to write readable queries, but you can still create N+1 patterns by fetching parents and then fetching children in a loop. I prefer using include or select to get related data in one query when the cardinality is reasonable. I als

Criterion is the standard benchmarking library for Rust. It runs benchmarks multiple times, detects outliers, and reports statistical confidence intervals. The API is simple: wrap your code in a closure, and criterion measures execution time. It gener

SQL joins combine data from multiple tables. INNER JOIN returns matching rows only. LEFT/RIGHT JOIN includes all rows from one table, nulls for non-matches. FULL OUTER JOIN combines both. I use CROSS JOIN for Cartesian products sparingly—performance k

Rendering thousands of list items kills performance. Virtual scrolling renders only visible items plus a buffer, dramatically reducing DOM nodes. The react-window library provides FixedSizeList and VariableSizeList components that handle viewport calc