Poor Lighthouse performance on Prompts page (prod) — score 30/100

[Aryansharma28]

Summary

A Lighthouse audit against production on the Prompts page returned a Performance score of 30/100. Most Core Web Vitals are in the red. Filing so we can triage what's dragging the page down.

Environment

• Target: production (app.langwatch.ai)
• Page: Prompts — https://app.langwatch.ai/redteaming-TfdqK0/prompts
• Tool: Lighthouse (mobile profile), run 2026-07-03
• Note: Values are estimated and vary run-to-run; treat as directional, not exact.

Lighthouse results

Metric	Value	Status
Performance score	30	🔴
First Contentful Paint (FCP)	2.8 s	🔴
Largest Contentful Paint (LCP)	4.3 s	🔴
Total Blocking Time (TBT)	1,280 ms	🔴
Speed Index	4.4 s	🔴
Cumulative Layout Shift (CLS)	0.042	🟢

Observations

• TBT of 1,280 ms is the loudest signal — that's a lot of main-thread blocking, which usually means heavy JS execution/hydration on load.
• LCP 4.3 s and Speed Index 4.4 s are consistent with the page being JS-bound rather than layout-bound.
• CLS 0.042 is good — layout stability is not the problem, so this is about how much JS we ship/execute, not visual jank.

Suggested next steps

• Reproduce with a fresh Lighthouse run (incognito, extensions off) to rule out client-side noise.
• Pull the Lighthouse "Opportunities/Diagnostics" (unused JS, long tasks, bundle breakdown) for this route.
• Check the Prompts route bundle size / hydration cost — candidate for code-splitting or deferring non-critical JS.
• Confirm whether this is Prompts-specific or a shared app-shell cost affecting other routes too.

cc @0xdeafcafe @sergioestebance