Intermediate terms
itertools Patterns
Python 3.8+
Standard-library building blocks for lazy, memory-efficient iteration over finite, infinite, or combinatorial sequences without materializing intermediate lists.
1mo ago
Python intermediate
Iterating Objects with foreach (Iterator & IteratorAggregate)
PHP 5.5+
3
foreach can traverse any object implementing Iterator or IteratorAggregate, not just arrays — control iteration without exposing internal state.
3mo ago
PHP intermediate
Internal Developer Platform (IDP)
A curated, self-service layer on top of cloud and CI/CD infrastructure that product teams use to ship services without filing tickets — paved roads that make the right thing the easy thing.
5mo ago
DevOps 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.
6mo ago
Performance intermediate
INSERT ... ON DUPLICATE KEY UPDATE
PHP 5.1+
1
An atomic MySQL upsert — inserts a new row or updates the existing one if a unique key constraint would be violated.
6mo ago
Database intermediate
ICU Message Format
PHP 7.0+
1
A standard syntax for translatable strings that handles pluralisation, gender, number formatting, and date formatting in a single expression — supported by PHP's intl extension via MessageFormatter.
6mo ago
i18n intermediate
Import Maps
ES2020
2
Import maps let browsers resolve bare module specifiers (import 'lodash') without a bundler — mapping module names to URLs in a JSON script tag.
6mo ago
JavaScript intermediate
IntersectionObserver API
HTML5
1
IntersectionObserver fires when an element enters or leaves the viewport — the modern way to implement lazy loading, infinite scroll, and scroll-triggered animations.
6mo ago
JavaScript intermediate
Inverted Index
8
A data structure that maps each unique word to the list of documents containing it — the foundation of all full-text search engines, enabling fast lookup of documents matching a query term.
6mo ago
Search intermediate
IoC Container
PHP 7.0+
1
An Inversion of Control container automatically resolves and injects class dependencies — you declare what a class needs, the container figures out how to create it, eliminating manual dependency wiring.
6mo ago
Code Quality intermediate
Implicit Globals & strict mode
ES5
Assigning to an undeclared variable in non-strict mode silently creates a global — use 'use strict' or ES modules to prevent accidental global pollution.
6mo ago
JavaScript intermediate
Integer Overflow & PHP_INT_MAX
PHP 4.0+
PHP integers silently overflow to float when exceeding PHP_INT_MAX (9.2×10¹⁸ on 64-bit) — use BCMath or GMP for arbitrary precision arithmetic.
6mo ago
PHP 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.
6mo ago
Performance intermediate
InnerSource
1
Open-source collaboration practices inside an organisation — any team can contribute to any internal repository, reducing silos.
6mo ago
General intermediate
Insecure Randomness
PHP 7.0+
1
Using non-cryptographic random functions (rand(), mt_rand(), array_rand()) for security tokens — these are predictable and enable token forgery, session prediction, and CSRF bypass.
6mo ago
Security intermediate
Intl API
ES2015
1
The built-in JavaScript internationalisation API — format numbers, dates, currencies, relative times, and lists correctly for any locale without external libraries.
6mo ago
JavaScript intermediate
Idempotency
4
An operation is idempotent if performing it multiple times produces the same result as performing it once — essential for safe retries.
6mo ago
General intermediate
Immutable Infrastructure
PHP 5.0+
2
Servers are never modified after deployment — to update, you build a new image and replace the old server entirely, eliminating configuration drift.
6mo ago
DevOps intermediate
Inappropriate Intimacy
Two classes that access each other's private fields and internals too freely, creating tight bidirectional coupling.
6mo ago
Code Quality intermediate
Incident Response
PHP 5.0+
6
A structured process for detecting, containing, investigating, and recovering from security incidents or system failures.
6mo ago
DevOps intermediate