Performance terms
Every millisecond matters — here is how to win them back
Slow software costs money, loses users, and erodes trust. Performance engineering covers profiling, caching strategies, database query optimisation, network latency, memory management, and the architectural patterns that keep systems fast under real-world load. Most performance problems are invisible until they are not — these terms help you find and fix them before your users do.
Memory Pressure Detection PHP 7.0+
Proactively identifying when a PHP process approaches its memory limit so corrective action can be taken before a fatal error.
2d ago
performance intermediate
Core Web Vitals
Google's three field-measured performance metrics — LCP (loading), INP (interactivity), CLS (visual stability) — used as direct search ranking signals since 2021.
1mo ago
performance intermediate
Cumulative Layout Shift (CLS)
A Core Web Vital that measures unexpected visual movement of page elements during load — caused by images without dimensions, late-injected content, and font swaps. Target: under 0.1.
1mo ago
performance intermediate
Image Optimisation
Reducing image file size and delivery overhead through format choice (AVIF, WebP), compression, responsive sizing (srcset), lazy loading, and explicit dimensions — the single highest-impact performance lever for most websites.
1mo ago
performance intermediate
Largest Contentful Paint (LCP)
A Core Web Vital that measures when the largest above-fold content element (typically the hero image or main heading) becomes visible — target under 2.5 seconds. The most impactful page speed metric.
1mo ago
performance intermediate
Resource Hints (preconnect, prefetch, preload)
HTML link attributes that instruct the browser to take early action on resources — opening connections, fetching future pages, or loading critical assets before they are discovered in HTML parsing.
1mo ago
performance intermediate
Caching Strategies PHP 7.0+
Patterns for when and how to store and invalidate cached data — cache-aside, write-through, write-behind, and read-through each make different trade-offs between consistency, complexity, and performance.
2mo ago
performance intermediate
Brotli vs gzip Compression PHP 5.0+
Brotli (br) compresses 15-25% better than gzip for text content — use Brotli for supported browsers (all modern ones), gzip as fallback, both configured at the server level not PHP.
2mo ago
performance intermediate
Cache Warming Strategies PHP 5.0+
Pre-populating a cache before traffic arrives — preventing the cold-start thundering herd where every request misses a cold cache simultaneously after a deploy.
2mo ago
performance intermediate
Image Optimisation PHP 7.0+
Serving images in modern formats (WebP, AVIF), at the correct size, with appropriate compression — typically the single biggest performance win for image-heavy pages.
2mo ago
performance intermediate
Resource Prefetching HTML5
dns-prefetch, preconnect, preload, and prefetch hints — fetching critical resources early to reduce perceived load time.
2mo ago
performance intermediate
APCu — In-Process User Cache PHP 5.4+ APCu stores PHP values in shared memory within the PHP-FPM pool — the fastest possible cache with no network hop overhead.
2mo ago
performance intermediate
Async Processing / Job Queues PHP 5.0+ Deferring time-consuming work (emails, image processing, third-party API calls) to background workers via a queue, improving response times.
2mo ago
performance intermediate
Caching Strategies (APCu, Redis, Memcached) PHP 5.0+ Storing computed results or fetched data so future requests can be served without repeating expensive operations.
2mo ago
performance intermediate
CDN Edge Caching PHP 5.0+ Content Delivery Networks cache responses at edge nodes close to users — reducing latency and origin load, controlled via Cache-Control headers.
2mo ago
performance intermediate
Connection Pooling PHP 5.0+ Reusing a pool of pre-established database connections rather than opening and closing a new connection on every request.
2mo ago
performance intermediate
Covering Index An index that contains all columns referenced by a query, allowing the database to answer it entirely from the index without touching the table.
2mo ago
performance intermediate
Database Indexing PHP 5.0+ Indexes are data structures that allow the database to find rows matching a WHERE clause without scanning the entire table.
2mo ago
performance intermediate
Debouncing & Throttling ES5 Debounce delays execution until input stops; throttle caps execution to once per interval — both control the frequency of expensive operations.
2mo ago
performance intermediate
Eager Loading PHP 5.0+
Loading related data upfront in a single query rather than deferring until access, preventing N+1 query problems.
2mo ago
performance intermediate