WordPress

WP_DEBUG and logging, Query Monitor, debugging hooks and AJAX, and reading fatal error reports.

Add sortable columns to post lists and simple dashboard widgets.

Architecture for high-traffic WordPress: caching layers, database scaling, media offloading and search.

Find tickets, set up the core development environment, write patches and get them reviewed.

Sanitise input, validate it, and escape output with the right function for each context.

Environments, database search and replace, media, configuration per environment and rollbacks.

What nonces are and are not, adding them to forms, AJAX and REST requests, and verifying them.

Create a plugin with a header, hook into WordPress and activate it.

Run custom queries with $wpdb->prepare, table prefixes, and when to avoid raw SQL.

Organise files, prefix everything, guard direct access and keep the main file small.

Store settings with the Options API, cache expensive results with transients, and watch autoloaded data.

Run setup on activation, clean up on deactivation, and remove data on uninstall when users ask for it.

Manage sites, content, plugins and the database from the command line, and write custom commands.

Add admin menus and submenus with the right capabilities, and render admin pages.

Make code translatable with __ and friends, text domains, JavaScript translations and translation files.

Register settings, sections and fields with sanitisation, so options save securely.

The object cache API, persistent backends such as Redis, cache groups and invalidation.

Register shortcodes with attributes, return output safely, and when a block is better.

How full-page caches and CDNs serve WordPress, what breaks caching, and purging on updates.

Create and upgrade tables with dbDelta, version the schema, and when meta is the wrong store.