Building a WordPress plugin that passes the WordPress.org review requires strict adherence to coding standards, security best practices, and performance optimization.
Security essentials: 1) Nonces on every form (wp_nonce_field/wp_verify_nonce). 2) Capability checks (current_user_can) on every admin action. 3) Sanitize ALL input: sanitize_text_field(), absint(), esc_url_raw(). 4) Escape ALL output: esc_html(), esc_attr(), esc_url(), wp_kses(). 5) Never use eval(), never trust $_GET/$_POST without sanitization.
Performance: Enqueue scripts/styles only where needed (check the current page before loading). Use transients for caching API responses. Minimize database queries — batch operations instead of per-item queries. Use wp_remote_post() instead of cURL for HTTP requests (respects WordPress proxy settings).
Coding standards: TABS for indentation (not spaces!). Yoda conditions: if ( ‘value’ === $var ). Snake_case for functions, PascalCase for classes. File naming: class-name-here.php. Prefix everything with your plugin slug to avoid conflicts.
The WordPress Settings API handles option storage, validation, and nonce verification in one place. Use register_setting() with a sanitize_callback for validation. Group related options in a single array option to reduce database queries.