How do I know if my store needs performance work?

Three quick checks: (1) Run your homepage through PageSpeed Insights, if the mobile score is below 70, you’re leaving conversion money on the table. (2) Check Search Console > Core Web Vitals, any URL flagged as “Poor” is a Google ranking liability. (3) Time-to-first-byte, if your TTFB is over 800ms on a warm cache, your stack is misconfigured. The free 30-min audit covers all three plus a slow-query log review, you get a written report whether or not you go ahead with the fix.