Custom Web Applications, built for Core Web Vitals

Fast, accessible, secure web platforms — engineered so that speed becomes a revenue line, not an afterthought.

Updated

A slow web app is not a cosmetic problem. It is a tax you pay on every visit — in lost conversions, in lower search rankings, in users who leave before they ever see what you built. The good news is that this tax is measurable, and once it’s measurable, it’s an engineering target like any other.

This is how we think about building web applications: performance is a first-class requirement, written into the budget on day one, not bolted on after launch.

Speed is a revenue metric

The clearest evidence comes from Deloitte and Google’s Milliseconds Make Millions study, which instrumented 37 brands across 30 million-plus user sessions. A 0.1-second improvement in mobile load time moved the numbers that matter:

MetricLift from a 0.1s speed-up
Retail conversions+8.4%
Retail average order value+9.2%
Travel conversions+10.1%

A tenth of a second. The flip side is just as stark: Google found that 53% of mobile visits are abandoned if a page takes longer than three seconds to load. The curve below is the shape every team eventually meets — the probability of a bounce climbs steeply as load time grows.

Relative bounce probability
Directional, after Google/SOASTA mobile retail data — the relative increase in bounce probability as load time grows. The steepest damage happens in the first few seconds. Scrub across it.

This is why we treat the first few seconds as the whole game.

Core Web Vitals are the scoreboard — and a ranking signal

Google’s Core Web Vitals turn “feels fast” into three numbers, measured on real users at the 75th percentile. Hitting “good” means:

  • LCP (Largest Contentful Paint) ≤ 2.5s — the main content paints quickly.
  • INP (Interaction to Next Paint) < 200ms — the page responds promptly to taps and clicks.
  • CLS (Cumulative Layout Shift) < 0.1 — nothing jumps around as it loads.

These aren’t vanity metrics. Google confirms Core Web Vitals are part of its page-experience ranking signals — so the same work that makes a site feel fast also makes it easier to find. Teams that took them seriously saw it in the business numbers:

TeamChangeResult
Vodafone31% better LCP+8% sales, +15% lead-to-visit rate
Pinterest40% less perceived wait+15% sign-ups, +15% SEO traffic
CdiscountImproved all three CWV+6% revenue
NDTVHalved LCP~50% lower bounce rate

How we build to hit them by default

The reason most apps fail Core Web Vitals is structural: they ship a blank page, then a large JavaScript bundle that has to download, parse, and execute before anything is interactive. The median page today ships over 550 KB of JavaScript on mobile (HTTP Archive, 2024) — far above the budget a sub-three-second load actually allows.

We invert that. Content is pre-rendered and served from the edge, close to the user. CSS for the first screen is inlined so nothing shifts. JavaScript is shipped only where interactivity actually lives — an “islands” model — instead of hydrating the entire page. Pre-rendered HTML and critical CSS paint immediately; only the interactive islands ship JavaScript, and every metric is measured at the 75th percentile of real users.

And because performance rots silently as features pile on, we make it a build gate. A performance budget lives in our build pipeline — hard caps on JavaScript size, total page weight, LCP and INP — and if a release regresses past those limits, it fails the check before it ever reaches your users.

That’s the whole philosophy: make speed a number, put the number in front of the team, and refuse to regress it. The result is a web application that’s fast on the median phone — which is where your customers actually are.

References

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