WordPress Core Web Vitals & JavaScript Error Fix — Code-Level Repair Needed

We need an experienced WordPress performance developer to fix known JavaScript console errors and Core Web Vitals issues on our WordPress site: babyem.co.uk This is not a general audit or plugin-based speed optimisation task. We already know the main issues from Microsoft Clarity and performance reports. We need someone to complete the actual repair work. This must be a code-level fix. We do not want someone to simply install or configure WP Rocket, LiteSpeed Cache, Autoptimize or another caching/optimisation plugin. Plugins can temporarily improve PageSpeed numbers, but the underlying issues remain. We need the problems fixed in the theme/plugin/code where they are actually happening. Known issues from Microsoft Clarity last week: JavaScript errors — 98 total errors, affecting 10.54% of sessions: * `"$ is not a function"` — 58.16% * `"ResizeObserver loop completed with undelivered notifications"` — 29.59% * Duplicate variable declaration on appendChild for `sheet_csv_url` — 4.08% * `"i.data.indexOf is not a function"` — two variants, 3.06% + 1.02% * `"Can't find variable: _autofillcallbackhandler"` — 2.04% * Generic script error — 1.02% Performance / Core Web Vitals: * Overall score: 51/100 across 126 pageviews * 23.8% good * 30.2% needs improvement * 46.0% poor * LCP: 19s, poor * INP: 450ms, needs improvement * CLS: 1, poor The work needed: * Fix the JavaScript console errors at source * Fix the heavy/conflicting JavaScript causing the console errors * Clean up and minify the JS/CSS causing render-blocking delays * Correct script loading order where needed * Defer, remove or conditionally load non-critical scripts where safe * Properly compress, resize and re-upload images causing slow LCP scores * Improve LCP, INP and CLS across the affected priority pages * Work safely on staging before pushing anything live * Provide before/after evidence using PageSpeed Insights, Lighthouse, Chrome DevTools, WebPageTest or similar * Provide a short summary of what was changed Access: * WordPress access is available * Everything for the site lives in WordPress * Microsoft Clarity access can be granted if needed to review recordings, heatmaps or error data * Please confirm which email address we should add if you need Clarity access Deliverable: We need the known issues fixed, with an estimated timeline and clear scope for completing the repair. Please apply only if you can do code-level WordPress performance repair, not just plugin setup. Please start your application with “Code-level WordPress repair” so we know you have read the brief properly.