Terms starting with "L"
Load Balancer Types — L4 vs L7
Layer-4 load balancers forward raw TCP/UDP packets based on IP and port; layer-7 load balancers terminate HTTP and route based on paths, headers and cookies — different trade-offs for different traffic.
3w ago
cloud 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
Linux File Permissions
Read, write, and execute permissions assigned to owner, group, and others — the foundation of Linux access control for web application files.
CWE-732 OWASP A5:2021
1mo ago
linux beginner
7.5
LLM Temperature & Sampling Strategies Parameters that control the randomness and diversity of LLM output — temperature scales token probabilities, while top-p and top-k limit the candidate pool before sampling.
1mo ago
ai_ml intermediate
Late Static Binding — PHP 5.3 Feature PHP 5.3+
static:: (Late Static Binding, PHP 5.3) refers to the called class at runtime — unlike self:: which always refers to the class where the method is defined.
2mo ago
php intermediate
Leader Election in Distributed Systems
A coordination protocol where distributed nodes agree on a single 'leader' that takes responsibility for a specific task — preventing multiple nodes from performing the same action simultaneously (duplicate work, split-brain).
2mo ago
architecture advanced
LLM Hallucination
When a large language model generates confident-sounding text that is factually incorrect, fabricated, or unsupported by any source — a fundamental property of how language models work.
2mo ago
ai_ml intermediate
LLM Streaming Responses PHP 8.0+
Receiving LLM output token-by-token as it is generated rather than waiting for the full response — dramatically improving perceived latency for users and enabling real-time displays of AI-generated content.
2mo ago
ai_ml intermediate
Lock-Free Programming
Lock-free algorithms guarantee system-wide progress without mutexes — using atomic CPU instructions (CAS) so at least one thread always makes forward progress even if others are delayed.
2mo ago
concurrency advanced
Log Aggregation (ELK/Loki)
Log aggregation collects logs from all services into a central searchable store — ELK (Elasticsearch+Logstash+Kibana) for full-text search, Loki (Prometheus-style) for cost-efficient label-based search.
2mo ago
observability intermediate
Log Levels & When to Use Each
Log levels (DEBUG, INFO, WARNING, ERROR, CRITICAL) communicate severity — use the right level so alerts fire on real issues and noise doesn't mask real problems.
2mo ago
observability beginner
Lookahead & Lookbehind PHP 5.3+
Zero-width assertions that match a position based on what precedes or follows it, without consuming characters — allowing conditions on surrounding context without including that context in the match.
2mo ago
regex intermediate
Latency vs Bandwidth
Latency is delay per request (physics + processing); bandwidth is throughput — high bandwidth does not fix high latency for small interactive responses.
2mo ago
networking intermediate
Lazy Loading Images
Deferring off-screen image downloads with loading="lazy" — improves initial page load and LCP by only fetching images as they approach the viewport.
2mo ago
frontend beginner
Lazy Objects (PHP 8.4) PHP 8.4+
PHP 8.4 native lazy object proxies defer initialisation until first access — enabling zero-cost dependency injection of services that may never be used in a request.
2mo ago
php advanced
Legacy Date Functions PHP 5.0+
Using date(), mktime(), strtotime(), and date_create() instead of DateTimeImmutable — the legacy functions are mutable, timezone-unsafe, and cannot be easily mocked.
2mo ago
php intermediate
Lexing & Parsing PHP 7.0+
Two stages of language processing — the lexer converts source text to tokens, the parser converts tokens to an Abstract Syntax Tree representing the program's structure.
2mo ago
compiler advanced
Lines Too Long
Lines exceeding 120 characters force horizontal scrolling and break side-by-side diff views — PSR-12 recommends a soft limit of 120 and hard limit of no limit, but team conventions often enforce 120.
2mo ago
style beginner
Linux Log Files
Log locations, rotation, and analysis tools on Linux — /var/log/ structure, journald, logrotate, and essential log analysis commands.
2mo ago
linux intermediate
Linux Memory Management
How Linux allocates RAM — virtual memory, the page cache, swap, and the OOM killer — and what PHP developers need to know when PHP processes run out of memory.
2mo ago
linux intermediate