What I Do

I find and fix the root causes of slowness in React and Next.js apps, including:

• Failing Core Web Vitals (LCP, INP, CLS);
• Large bundles & hydration bottlenecks;
• Runtime freezes and rendering stalls;
• API slowness and blocking waterfalls;
• Long build times and CI/CD delays;
• Cloud inefficiencies and wasted infra spend.

I create the strategy, guide your team through the fix, or implement it directly – whatever gets you to "fast" the fastest.

What You Get

A faster, smoother, more scalable product – with measurable results:

• Faster loads → higher user engagement and conversions;
• Better responsiveness → fewer complaints and smoother UX;
• Smaller bundles → faster loads, better user experience, and lower hosting costs;
• Faster builds → higher developer velocity;
• Clear performance ownership → fewer regressions over time.

Every engagement uses fixed pricing and fixed outcomes. No hourly billing. No open-ended consulting cycles.

Case Studies

• Building a High-Scale Real-Time Portfolio Engine for a Multi-Chain DeFi Platform

  A real-time streaming architecture that stayed smooth with thousands of positions across chains, protocols, and wallets.

• Next.js App Speedup by Fixing Server Fetching & Blocking Waterfalls

  Removed nested layout waterfalls, consolidated RSC data loading, and improved TTFB by 40% and LCP by 35%.

• Rendering & React Performance Deep Dive for a High-Scale DeFi Portfolio UI

  Virtualized heavy lists, eliminated rendering stalls, replaced slow CSS-in-JS, and achieved stable 60 FPS under load.

How It Works

1. You describe what's slow and share access
2. I run an initial review
3. If the root cause is obvious, we move straight to fixing
4. If not, I recommend a full audit with fixed pricing – so you always know the cost before committing
5. We agree on scope, outcomes, and fixed pricing
6. We fix the issues and transfer the knowledge back to your team

Who I Work With

I work with teams where performance issues have real business impact – slower conversions, higher costs, or blocked launches.

You get the most value if:

• You want a clear performance strategy;
• Your team is ready to implement;
• You prefer lasting fixes over quick hacks.

About Me

I'm Stepan – a Software Engineer specializing in Web Performance, React and Next.js.

I've worked with early-stage startups, high-growth SaaS teams, and billion-dollar companies serving millions of users. I've solved everything from failing Web Vitals to runtime freezes to infrastructure costs growing faster than revenue.

I know where performance issues come from – and how to fix them quickly, cleanly, and without rewrites.