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Senior web & app development · 20 capabilities
oakstone.digital
Platform & support / capability

Speed & performance optimisation
measured where revenue is.

Core Web Vitals, bundle size and server response times taken seriously enough to move revenue.

This is for you if
  • Search Console flags Core Web Vitals as needing improvement
  • Mobile conversion is far below desktop
  • The site got slower with every marketing tag added
A sharper way forward

The work should
change the numbers.

Tools we reach for
Lighthouse CIWebPageTestCloudflareVercelSharpPartytown

Performance work goes wrong when it chases a Lighthouse score. A synthetic 98 means very little if your actual users are on mid-range Android phones over congested networks, which is what field data usually reveals.

We start with real-user measurement, find the two or three causes responsible for most of the damage, and fix those at the source. Usually it is images, third-party scripts, render-blocking CSS, and a server response time nobody has looked at in two years.

Then we install budgets in CI, because performance is not a project. Without a gate, every optimisation is undone within six months by well-intentioned additions.

What's included

What the engagement
actually contains.

01

Field and lab measurement

Real-user Core Web Vitals segmented by device, country and template, alongside controlled lab runs.

02

Critical path optimisation

Render-blocking resources removed, critical CSS inlined, fonts loaded without layout shift.

03

Image and media pipeline

Modern formats, correct sizing, aspect-ratio reservations and lazy loading applied properly.

04

Third-party script control

Tags audited for actual value, then deferred, proxied or removed — usually the single biggest win.

05

Server and caching strategy

TTFB improved through caching layers, CDN rules and query tuning rather than more hardware.

06

Performance budgets in CI

Automated Lighthouse and bundle-size gates that fail a pull request before a regression ships.

What you get
  • Baseline field and lab performance report
  • Prioritised fix list with expected impact
  • Implemented optimisations with before/after evidence
  • Image and asset pipeline configuration
  • CI performance budgets
  • Ongoing Core Web Vitals dashboard
Signals it is time
  • Search Console flags Core Web Vitals as needing improvement
  • Mobile conversion is far below desktop
  • The site got slower with every marketing tag added
  • Speed was fixed last year and has drifted back
Common mistakes we fix

What usually went wrong
before we were called.

  • 01Optimising for a lab score while field data tells a different story
  • 02Adding a tag manager and never auditing what it loads
  • 03Lazy-loading the hero image and hurting the very metric you are chasing
  • 04Fixing performance once with no budget in CI to hold it
How we measure it
  • Field LCP, INP and CLS by device
  • Mobile conversion rate
  • Total page weight and request count
  • Budget failures caught in CI
Typical timeline

2–4 weeks for the first measurable pass

Practicalities

What week one
actually looks like.

First week

Field data segmented by device, country and template alongside lab runs, so the fix list is aimed at where the damage actually is rather than at a synthetic score.

What we need from you
  • Analytics and Search Console access
  • Repository and deployment access
  • A decision-maker for third-party script removal
  • CDN and hosting credentials
Not included
  • Redesigning pages, unless scoped
  • Rewriting the application architecture
  • CDN or hosting upgrade costs
  • Ongoing monitoring, unless retained

Scope boundaries stated up front rather than discovered in a change request.

How the work runs

Four stages, visible throughout.

01

Assess

A baseline across performance, security, accessibility and dependency risk, with findings ranked by consequence.

02

Stabilise

The urgent items closed first: exposed surfaces, failing checks, missing backups, unpatched dependencies.

03

Automate

Budgets, scans and alerts moved into CI and monitoring, so regressions are caught by machines rather than customers.

04

Review

A quarterly session on what changed, what is drifting and what deserves next quarter’s attention.

Questions buyers actually ask

Speed & performance optimisation, answered.

On mobile commerce and lead generation, reliably yes — and the mechanism is simple: fewer people abandon before the page is usable. We baseline conversion by device before starting so the outcome is measured rather than asserted.

Partly. Some tags can be deferred, proxied or moved to a worker with no loss of function. Others genuinely cost what they cost, and the honest conversation is whether that tag earns its weight. We give you the numbers per tag so it is your decision.

As long as the budgets stay in CI. Without a gate, expect regression within two quarters. With one, a failing pull request tells the person who added the regression, at the moment they added it.

A better brief starts here

Make speed & performance optimisation useful.

Bring us the hard thing. We will bring a point of view, a senior team and a clear next step.

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