WordPress / Intermediate

Cache expensive queries

Use transients for custom queries that do not need to hit the database every request.

Why this matters

The production reason.

Repeated custom queries can hit the database on every page view, even when the result changes only a few times per day.

Transients let you cache the computed result and refresh it on a schedule or when content changes.

Use this for popular posts, related products, taxonomy-heavy lists, and dashboard summaries.

Copy-ready example

$cache_key = 'theme_popular_posts';
$posts = get_transient( $cache_key );

if ( false === $posts ) {
  $posts = new WP_Query([
    'posts_per_page' => 6,
    'meta_key' => 'views',
    'orderby' => 'meta_value_num',
  ]);

  set_transient( $cache_key, $posts, HOUR_IN_SECONDS );
}

Platform notes.

How this applies outside a perfect demo, including frameworks, CMS platforms, stores, and builder workflows.

WordPress: Clear transients when the related content is updated.

WooCommerce: Cache product lookups, but avoid caching user-specific cart data.

Managed hosting: Pair transients with object cache when Redis is available.

Explore other stacks

Jump into a different technology.

Move from this WordPress note into related HTML, CSS, Next.js, JavaScript, React, WordPress, and performance lessons.

Next.js

Use generateStaticParams for dynamic routes

Pre-render dynamic pages at build time instead of on every request to cut TTFB.

React

Keep state close to the interaction

Local state avoids unnecessary parent renders and keeps component intent obvious.

JavaScript

Abort stale fetch requests

Cancel outdated browser requests so fast UI changes do not render old data.

CSS

Use clamp for fluid spacing

Fluid spacing keeps layouts responsive without a forest of breakpoint overrides.

Performance

Compress images before deploy

Oversized images are still the easiest way to lose LCP before users see anything.

HTML

Use real buttons for actions

If it changes state, use button. If it navigates, use a link.