Laravel-teljesítmény és cache

Laravel Performance & Cache

Measure first, then eliminate N+1 and over-fetching

• Gather concrete evidence before optimizing: inspect executed queries (DB::listen, assertQueryCount, Debugbar/Telescope logs or EXPLAIN) to identify the actual bottleneck.
• Eager load every relationship accessed in loops, Blade views or API Resources (with(['author:id,name', 'comments.user'])). When constraining columns on an eager load, always include the primary key (id) and foreign key (user_id) or Eloquent cannot link the models.
• Respect Model::preventLazyLoading() if enabled in the project.
• Select only needed columns (select(['id', 'title', 'created_at'])), and avoid loading TEXT/BLOB columns on list endpoints.
• Paginate list endpoints (paginate(), simplePaginate() or cursorPaginate() for deep pages). Never return unbounded Model::all() or ->get() results on growing tables.
• Use exists() / doesntExist() instead of count() > 0, and withCount() / withSum() / withAvg() instead of loading full relation collections just to count or sum them.

Caching and key hygiene

• Use Cache::remember($key, $ttl, fn () => ...) or Cache::flexible($key, [$fresh, $stale], fn () => ...) (Laravel 11.23+) for expensive, read-heavy queries, and Cache::memo() (Laravel 12+) when repeating reads within a single request.
• Scope every cache key with a clear prefix and all parameters that affect the output: tenant/organization ID, user/role context, locale, filters and page ("tenant:{$tenantId}:user:{$userId}:stats"). Never share a cache key across tenants or permission levels.
• Pair every cached value with an explicit TTL and invalidation strategy (Cache::forget(...) on model writes/events or cache tags on Redis/Memcached).
• Never use caching to mask broken authorization, inconsistent state or an easily fixed N+1 query, and never flush production caches without explicit authorization.