01
Core Web Vitals diagnosis
Tracing LCP, INP and CLS problems to their cause with DevTools traces, real-user monitoring and the Chrome UX Report.
Senior / Staff
Hire frontend performance and Core Web Vitals engineers
Performance engineers who find what makes pages slow — oversized bundles, long tasks, late images, layout shifts — fix it, and show the result in field data.
Role profile
What we look for in a Senior Frontend Performance Engineer
Seniority and experience are agreed in the proposal, and you interview every engineer before they start. These are the skills that interview should test.
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Bundle reduction
Analyzing bundles, removing duplicate libraries, code-splitting heavy dependencies and deferring non-critical scripts.
03
Caching and streaming
CDN caching rules and streamed server rendering, so the first meaningful bytes arrive early.
Typical work
What a Senior Frontend Performance Engineer typically works on
Examples of the scope this role is hired for. Your statement of work sets the actual deliverables and how they are accepted.
- 01Mobile LCP and INP work on your highest-traffic templates, measured in field data
- 02Less client JavaScript by moving work into Server Components
- 03Breaking up long tasks to improve Interaction to Next Paint
- 04Edge caching and personalization without a slower time to first byte
Stack and tools
What this role works with day to day. Tell us your stack and we’ll say plainly which parts we can staff.
- Next.js
- Core Web Vitals
- Chrome DevTools
- Lighthouse CI
- Cloudflare
- React 19
Technology guides
Related service
Web & frontend developmentField Core Web Vitals measured before and after, and a replatform shipped route by route — while your team keeps releasing weekly.
How hiring works
Four steps, agreed in writing before anyone starts
01
Tell us the role
The stack, the seniority you need, the hours you want covered, and any certifications the work requires. We reply within one business day.
02
We propose engineers
A written proposal sets out who we'd put forward, their seniority and experience, the scope, and the terms. If we can't staff the role well, we say so.
03
You interview every engineer
Nobody starts on your codebase until you've interviewed them and agreed. Use the skills on the role page as your interview checklist.
04
Working arrangements go in the SOW
Working-hours overlap is agreed for each engagement and written into the statement of work — the shared window, who shifts hours, and how handoffs work outside it.
QuantmHill provides development teams from India for Indian startups and SMEs. Role profiles describe project capabilities; availability is confirmed for your engagement. Our team works on India Standard Time. Project working hours, availability and handoff responsibilities are agreed before kickoff.
Need specific certifications? Tell us at the start and we'll confirm whether we can staff to that requirement before you sign. There are no recruiting fees.
FAQ
Questions about hiring a Senior Frontend Performance Engineer
Answered the way we would on a call. If yours isn’t here, send it — we reply within one business day.
We record performance traces to find long tasks — anything over 50 ms on the main thread — then split the work, defer it, or move it off the main thread with startTransition, scheduler yields or a web worker.
Faster pages lose fewer visitors, but how much that is worth depends on your traffic and funnel. We measure field Core Web Vitals before and after the work and compare conversion in your own analytics, rather than quoting industry averages.
Related roles
Similar and adjacent roles
Add a Senior Frontend Performance Engineer to your team
Tell us the stack, the seniority you need and the hours you want covered. We reply within one business day, and you interview every engineer before they start.