Fix React Performance Issues — Without Re-launching Your Site
React fixed without rewriting the world
Fix React Performance Issues — done properly, by senior engineers
A slow React app almost never needs a rewrite — it needs a profiler and an engineer who can read it. The usual culprits are unstable references that defeat memoisation, context that re-renders half the tree on every change, long lists rendered without virtualisation, and effects doing expensive work on every commit. We profile your app under realistic load, find the specific components and hooks driving the cost, and fix them surgically — tightening render scopes, stabilising dependencies, virtualising heavy lists, and moving expensive work off the main thread. Every change is covered by a regression test for the path we fixed and lands as a pull request you review, so the app gets faster without the risk and cost of starting over.
What you're seeing
Your React app feels heavy: slow filters, janky modals, sluggish lists, and a profiler that paints everything orange.
Our approach
We profile under realistic load, virtualise long lists, move expensive work off the main thread, and tighten render scopes. The app starts feeling instant.
Symptoms teams come to us with
- The UI lags on typing, scrolling or opening modals
- React DevTools profiler is solid red on every interaction
- Long sessions slow the tab down or eventually crash it
- A small data change re-renders half the component tree
What we check first
- 01Unstable references breaking memoisation and re-rendering children
- 02Effects with wrong dependencies firing in loops
- 03Heavy lists and charts rendered without virtualisation
- 04Leaked listeners, timers and subscriptions holding memory
What you get
Concrete deliverables, no fluff
Every engagement ends with measurable, documented outcomes — no black-box agency reports.
Audit of the failing component tree
Refactor with memoisation + stable deps
Regression tests for the fixed paths
Hand-off doc explaining what changed and why
What changes after we ship
60fps interactions
Typing, scrolling and modals stop lagging once we cut the wasted renders the profiler reveals.
Virtualised heavy lists
Lists and tables with hundreds of rows render and scroll smoothly instead of re-painting everything.
Memory growth flatlined
We hunt the leaked listeners, timers and subscriptions so long sessions stop degrading the tab.
Regression tests on the fixed paths
The hot paths we fix are covered by tests so the performance win does not silently rot.
From brief to shipped fix
A transparent, low-risk process — a senior engineer reads your brief personally, and nothing starts until you approve a written plan and price.
Diagnose
A senior engineer reviews your brief, reproduces the issue, and pinpoints the real root cause — not the symptom — before any code is touched.
Scoped plan & quote
You get a written plan to fix React Performance Issues, a firm timeline, and a fixed quote. Nothing starts until you approve it — no surprise invoices.
Ship the fix
We implement on a branch and open a pull request you review, working to your code-review standards on your repo — never a black box.
Verify & hand off
We verify on staging and production, share before/after evidence where it applies, and leave you a short hand-off note so the fix sticks.
Situations we handle
A profiler painted solid red
Every interaction re-renders too much. We trace the cascade and stabilise it.
Janky lists and dashboards
Data-heavy screens drop frames. We virtualise and memoise the expensive parts.
A tab that slows over time
Long sessions creep toward a crawl. We diff heap snapshots and patch the leaks.
Why teams hand this task to Krapton
Senior engineers only
Your brief is read and handled by a senior engineer — no junior hand-off, no sales-rep filter in between.
Root cause, not a patch
We reproduce and fix the underlying cause, then add a guard so the same class of issue does not quietly return.
Your repo, your standards
Every change lands as a pull request you review, on your repository, following your existing review process.
NDA on day one
Confidentiality and IP are covered before we look at a single line of code. All work stays in your accounts.
Fixed quote up front
You approve a written plan and price before work starts. If scope changes, we re-quote in writing — no surprise invoices.
Proof, where it applies
Performance, SEO and reliability work ships with before/after evidence so the result is measurable, not anecdotal.
Three ways to engage
No retainer required. Pick the model that matches the work — pricing for this task starts from $2,000, with a fixed quote before anything starts.
Per task
Most popularOne clearly-scoped fix at a fixed price. Best when you know exactly what is broken and want it handled end to end.
- Fixed quote up front
- One PR, reviewed by you
- No retainer required
Hourly
Pay only for the hours worked. Best for diagnostics, audits, or exploratory work where the scope is still emerging.
- Weekly timesheets
- Pay for what you use
- No minimum commitment
Per sprint
A focused 1–2 week sprint when the work is bigger than one fix but smaller than a full project.
- 1–2 week blocks
- Clear sprint goal
- Scale up or stop anytime
Tooling we use
Industry-standard stack, no proprietary lock-in
Fix React Performance Issues — your questions, answered
How much does it cost to fix React Performance Issues?
Pricing starts from $2,000 and depends on the scope we find during the diagnostic. You get a fixed, written quote before any work begins — most engagements like this run 1–3 weeks.
How long does it take to fix React Performance Issues?
Typically 1–3 weeks for a focused engagement. After a short diagnostic we commit to a firm timeline so you know exactly what to expect.
Will you work directly on our existing codebase?
Yes. We work on your GitHub, GitLab or Bitbucket, ship every change as a pull request you review, and follow your code-review standards — not ours.
What exactly will I have at the end?
Concrete, documented outcomes — Audit of the failing component tree, Refactor with memoisation + stable deps, Regression tests for the fixed paths, and more. No black-box agency report.
How quickly can you start, and do you sign an NDA?
For a focused task like this we can usually start within 24–48 hours of the brief. We sign an NDA on day one, before we look at any code — yours or ours.
Will you fix this without rewriting our whole app?
Yes. We target the failing component trees and hot paths, refactor behind tests, and leave the rest of your codebase untouched. A full rewrite is almost never the right tool for a focused performance or behaviour bug.
Will you need to rewrite our app to fix the performance?
Almost never. Performance problems are nearly always localised to a few components and hooks. We profile, fix those surgically behind tests, and leave the rest of your codebase untouched — a rewrite is the most expensive and riskiest way to solve a focused perf bug.
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Let's get this off your plate
Send a 60-second brief on Fix React Performance Issues and a senior engineer replies within 24 hours with a plan and a fixed quote. NDA on day one, no retainer required.