How would you approach a performance review of a slow Salesforce page or process?

A systematic performance investigation covers multiple layers:

1. Page load performance: Use Salesforce Lightning Inspector (Chrome extension) to identify slow LWC/Aura components. Check for excessive wire calls, large data payloads, and missing caching.

2. SOQL and DML: Enable Apex debug logs at the PROFILING level. Identify SOQL queries with high execution time. Run slow queries in the Developer Console Query Plan tool to check for non-selective queries. Add custom indexes if needed.

3. Automation profiling: Check for excessive trigger chains, Process Builder processes, or Flows firing on the same record save. Consolidate automation into single triggers/flows.

4. Page layout complexity: Too many related lists, inline edit, real-time formula recalculations, and complex layouts degrade UI performance. Simplify layouts and use lazy-loading patterns.

5. Data volume: Related lists loading thousands of records cause UI timeouts. Use List Views with filters, restrict related list record counts, or replace inline lists with custom LWC with pagination.

6. Network: Use browser DevTools Network tab to identify large payload sizes and slow API responses. Enable HTTP/2 and CDN-hosted static resources.