Core retainer
A/B Test Development
Fixed tests per month, built in your testing tool. Cross-browser QA, launch support, and clean handover docs included.
from £2,000/mo
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A/B tests, built properly.
Experiment development for CRO teams and e-commerce brands — engineered, QA'd and launched without flicker, breakage or guesswork.
Free · 20 minutes · no pitch deck.
Experimentation engineering for sites serving millions of visitors a month — client-side and server-side.
What I do
Three ways to work together
Entry offer
Experimentation Audit
Technical review of your current test setup, QA of live experiments, tracking validation, and a written report with prioritised fixes.
£950 fixed
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Advisory
Experimentation Engineering Consulting
For teams moving from client-side to flag-based experimentation, or setting up a programme properly for the first time.
from £750/day
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Why it matters
Why tests built by an engineer are different
- No flicker. No breakage.
- Tests that don't flicker or break across browsers and devices, QA'd on real Safari, Chrome and Firefox — not just a single Chromium build.
- Built inside your stack.
- DOM-based or flag-based, built to fit how your codebase actually works — not bolted on top with fragile GTM hacks.
- QA'd like production code.
- Because it is. SRM checks, targeting validation, tracking verification — before launch, not after results come back wrong.
Recent writing
From the blog
5 min read technicalQA
QA-ing A/B tests inside shadow DOM: why your selectors lie to you
Shadow roots silently break querySelector-based test code and most QA tooling. Here's what's actually happening and how to write tests that work inside web components.
Read → 5 min read technicalarchitecture
DOM-injected vs flag-based experimentation: what changes when you go server-side
A practical comparison of client-side DOM manipulation and server-side flag-based testing — the trade-offs, the migration path, and what actually changes for the developer.
Read → 4 min read technicalflicker
Why your A/B test flickers — and how to actually fix it
Anti-flicker techniques demystified: why naive snippet placement causes visible page jank, what actually works, and why most implementations get it wrong.
Read →Let's talk about your testing programme.
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