wp-performance-review

WordPress Performance Review Skill

Overview

Systematic performance code review for WordPress themes, plugins, and custom code. Core principle: Scan critical issues first (OOM, unbounded queries, cache bypass), then warnings, then optimizations. Report with line numbers and severity levels.

When to Use

Use when:

• Reviewing PR/code for WordPress theme or plugin
• User reports slow page loads, timeouts, or 500 errors
• Auditing before high-traffic event (launch, sale, viral moment)
• Optimizing WP_Query or database operations
• Investigating memory exhaustion or DB locks

Don't use for:

• Security-only audits (use wp-security-review when available)
• Gutenberg block development patterns (use wp-gutenberg-blocks when available)
• General PHP code review not specific to WordPress

Code Review Workflow

1. Identify file type and apply relevant checks below
2. Scan for critical patterns first (OOM, unbounded queries, cache bypass)
3. Check warnings (inefficient but not catastrophic)
4. Note optimizations (nice-to-have improvements)
5. Report with line numbers using output format below

File-Type Specific Checks

Plugin/Theme PHP Files (functions.php, plugin.php, *.php)

Scan for:

• query_posts() → CRITICAL: Never use - breaks main query
• posts_per_page.*-1 or numberposts.*-1 → CRITICAL: Unbounded query
• session_start() → CRITICAL: Bypasses page cache
• add_action.*init.* or add_action.*wp_loaded → Check if expensive code runs every request
• update_option or add_option in non-admin context → WARNING: DB writes on page load
• wp_remote_get or wp_remote_post without caching → WARNING: Blocking HTTP

WP_Query / Database Code

Scan for:

• Missing posts_per_page argument → WARNING: Defaults to blog setting
• 'meta_query' with 'value' comparisons → WARNING: Unindexed column scan
• post__not_in with large arrays → WARNING: Slow exclusion
• LIKE '%term%' (leading wildcard) → WARNING: Full table scan
• Missing no_found_rows => true when not paginating → INFO: Unnecessary count