Intermediate terms
Recursion Patterns
PHP 5.0+
3
Functions that call themselves with smaller inputs — powerful for tree traversal, divide-and-conquer, and mathematical sequences, but requiring careful base cases and stack depth management.
6mo ago
Algorithms intermediate
Redis Patterns (Pub/Sub, Sorted Sets, Lua)
PHP 5.0+
1
Beyond key-value caching, Redis enables queues, leaderboards, rate limiting, pub/sub messaging, and distributed locks via its rich data structures.
6mo 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
6mo ago
Security intermediate
7.5
Refused Bequest
A subclass that inherits methods it doesn't need or want, signalling a misused inheritance relationship.
6mo ago
Code Quality intermediate
Regex in Loop
PHP 5.0+
1
Compiling and executing the same regular expression on every iteration of a loop — hoist the pattern outside.
6mo ago
Performance intermediate
Regex Syntax
PHP 5.3+
8
Regular expression syntax — anchors, quantifiers, character classes, groups, and alternation — the building blocks for pattern matching in PHP and all languages.
6mo ago
Regex intermediate
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
6mo 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.
6mo ago
Frontend intermediate
Replay Attack
PHP 5.0+
1
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
6mo ago
Security intermediate
7.5
Responsible Vulnerability Disclosure
6
The practice of privately reporting security vulnerabilities to vendors before publishing, allowing time for a fix.
6mo ago
General intermediate
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.
6mo ago
API Design intermediate
Retry Pattern with Exponential Backoff
PHP 5.0+
2
Automatically retrying failed operations with increasing delays — preventing thundering herd and handling transient failures gracefully.
6mo 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.
6mo 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.
6mo ago
i18n intermediate
Rolling Deployment
Gradually replacing old application instances with new ones, a few at a time, so the service remains available throughout the upgrade.
6mo ago
DevOps intermediate
Rate Limiting
PHP 5.0+
3
Restricting the number of requests a client can make in a given time window to prevent abuse, DoS, and credential stuffing.
CWE-770 OWASP A5:2021
7mo ago
Performance intermediate
Repository Pattern
PHP 5.0+
4
Abstracts the data persistence layer behind an interface, decoupling domain logic from database implementation details.
7mo ago
General intermediate
RangeError — Stack Overflow & Invalid Values
ES5
RangeError is thrown when a value is outside its allowed range — most commonly from infinite recursion (stack overflow) or invalid array/string sizes.
JavaScript intermediate