Terms starting with "R"
Redis Patterns (Pub/Sub, Sorted Sets, Lua)
PHP 5.0+
Beyond key-value caching, Redis enables queues, leaderboards, rate limiting, pub/sub messaging, and distributed locks via its rich data structures.
3mo ago
performance intermediate
ReDoS (Regex Denial of Service)
A crafted input causes a regex with catastrophic backtracking to consume excessive CPU, making the application unresponsive.
CWE-1333 OWASP A5:2021
3mo ago
security intermediate
7.5
Refactoring
PHP 5.0+
Improving code structure without changing its external behaviour — cleaning up debt while keeping tests green.
3mo ago
general beginner
Reflection API
PHP 5.0+
PHP's built-in introspection system for examining classes, methods, properties, and parameters at runtime.
3mo ago
php advanced
Refused Bequest
A subclass that inherits methods it doesn't need or want, signalling a misused inheritance relationship.
3mo ago
quality intermediate
Regex in Loop
PHP 5.0+
Compiling and executing the same regular expression on every iteration of a loop — hoist the pattern outside.
3mo ago
performance intermediate
Regex Performance
Regex performance pitfalls — catastrophic backtracking (ReDoS), unnecessary captures, and poorly anchored patterns that scan more input than needed.
3mo ago
regex advanced
Regex Syntax
PHP 5.3+
Regular expression syntax — anchors, quantifiers, character classes, groups, and alternation — the building blocks for pattern matching in PHP and all languages.
3mo ago
regex intermediate
register_globals (Legacy Audit)
PHP 5.0+
A removed PHP setting that automatically created global variables from GET/POST/COOKIE input, enabling trivial variable injection attacks.
CWE-473 OWASP A3:2021
3mo ago
php beginner
9.8
Regression Testing
Re-running existing tests after code changes to verify that previously working functionality has not been broken — the primary safety net for continuous delivery.
3mo ago
testing beginner
Remote File Inclusion (RFI)
PHP 5.0+
An attacker tricks include() or require() into loading a PHP file from an attacker-controlled remote URL, achieving code execution.
CWE-98 OWASP A3:2021
3mo ago
security intermediate
9.8
Render-Blocking Resources
CSS and synchronous JavaScript in <head> that prevent the browser from rendering any content until they are downloaded and parsed — the primary cause of slow First Contentful Paint.
3mo ago
frontend intermediate
Replay Attack
PHP 5.0+
An attacker captures a valid request or authentication token and resubmits it later to gain unauthorised access or repeat an action.
CWE-294 OWASP A2:2021
3mo ago
security intermediate
7.5
Responsible Vulnerability Disclosure
The practice of privately reporting security vulnerabilities to vendors before publishing, allowing time for a fix.
3mo ago
general intermediate
REST (Representational State Transfer)
1
An architectural style for distributed hypermedia systems using HTTP verbs, stateless interactions, and resource-oriented URLs.
3mo ago
architecture beginner
REST Architectural Constraints
PHP 5.0+
The six constraints Fielding defined for REST — statelessness, uniform interface, client-server separation, cacheability, layered system, and optional code on demand.
3mo ago
api_design intermediate
Retrieval-Augmented Generation (RAG)
1
A pattern that combines document retrieval with LLM generation — relevant documents are fetched and injected into the prompt context, grounding responses in current, specific data.
3mo ago
ai_ml advanced
Retry Pattern with Exponential Backoff
PHP 5.0+ Automatically retrying failed operations with increasing delays — preventing thundering herd and handling transient failures gracefully.
3mo ago
architecture intermediate
Reverse Proxy vs Load Balancer
A reverse proxy forwards client requests to backend servers, adding SSL termination, caching, and compression. A load balancer distributes traffic across multiple backends for scalability.
3mo ago
networking intermediate
Right-to-Left Language Support
HTML5
2
Design and implementation considerations for RTL languages (Arabic, Hebrew, Persian, Urdu) — text direction, mirrored layouts, and bidirectional text handling.
3mo ago
i18n intermediate