Intermediate terms
Cloud Multi-Tenancy
PHP 8.0+
Serving multiple customers (tenants) from shared infrastructure while keeping their data and behaviour isolated.
1d ago
cloud intermediate
Cloud Backup & Disaster Recovery
1
Automated backups with tested restores, defined RPO/RTO targets, and cross-region replication for catastrophic failure recovery.
2w ago
cloud intermediate
Cloud Region Selection
1
The decision of which cloud region(s) to deploy workloads into, balancing user latency, data residency law, cost, and service availability.
3w ago
cloud intermediate
Canonical URL (rel=canonical)
1
A <link rel='canonical'> tag that tells search engines which URL is the authoritative version of a page — preventing duplicate content from splitting ranking signals across multiple URLs.
2mo ago
frontend 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.
2mo 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.
2mo ago
performance intermediate
CSS Cascade Layers (@layer)
1
CSS @layer lets you explicitly define the order in which style groups are applied in the cascade — styles in a later layer always win over earlier ones regardless of specificity, eliminating specificity wars in large codebases.
2mo ago
frontend 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.
3mo ago
performance intermediate
Canary Deployment & Observability
Canary deployments route a small percentage of traffic to a new version — compare its golden signals against the stable version before full rollout to catch regressions automatically.
3mo ago
observability intermediate
Canvas API — 2D Drawing
HTML5
The HTML Canvas API provides a 2D drawing surface via JavaScript — used for charts, image manipulation, games, data visualisations, and any pixel-level rendering that DOM elements cannot efficiently handle.
3mo ago
javascript intermediate
Cardinality in Metrics
Cardinality is the number of unique label value combinations — high cardinality (user_id, URL, session_id as labels) creates millions of time series and crashes Prometheus.
3mo ago
observability intermediate
Cardinality in Observability
PHP 7.0+
The number of unique combinations of label values in a metric — high cardinality (millions of unique label combinations) causes memory exhaustion in time-series databases and is the most common observability scaling problem.
3mo ago
observability intermediate
Catastrophic Backtracking
PHP 5.3+
2
A regex engine failure mode where certain patterns combined with specific inputs cause exponential backtracking, making the match take seconds or minutes — a common denial-of-service vector called ReDoS.
3mo ago
regex intermediate
Code Readability Metrics
Readability can be measured — cyclomatic complexity, cognitive complexity (SonarQube), lines per function, parameter count, and nesting depth are all quantifiable proxies for readability.
3mo ago
quality intermediate
Collation & Locale-Aware Sorting
PHP 7.0+
1
Locale-specific rules for ordering strings alphabetically — determining that ä sorts near a in German but after z in traditional Swedish, and that sorting must not rely on byte values for Unicode text.
3mo ago
i18n intermediate
const Type Parameters (TS 5.0)
5.0
TypeScript 5.0 const type parameters infer literal types instead of widened types — const T extends string[] infers ['a','b'] not string[].
3mo ago
typescript intermediate
Consumer Groups
Consumer groups allow multiple consumers to process messages from a topic in parallel — each partition assigned to one consumer, enabling horizontal scaling without duplicate processing.
3mo ago
messaging intermediate
Copy-on-Write (CoW) in PHP Arrays
PHP 7.0+
PHP arrays are not copied when assigned or passed to functions — they share the same internal buffer until one copy is modified. Only then does PHP perform a real copy. This makes reading large arrays cheap but silent mutations expensive.
3mo ago
php intermediate
CORS — Cross-Origin Resource Sharing
PHP 7.0+
A browser security mechanism that blocks JavaScript from making HTTP requests to a different origin — PHP APIs must send specific headers to allow cross-origin requests from permitted frontend origins.
3mo ago
security intermediate
create_function() — The Dynamic Code Smell
PHP 4.0+
8
create_function() created anonymous functions from strings — deprecated PHP 7.2, removed PHP 8. It used eval() internally, risked code injection, and was always replaceable with proper closures.
3mo ago
php intermediate