PHP · Python · Multiple frameworks · Ecommerce speciality
Slow, invisible to search, or stuck half built? I step in and fix it.
COULLWORKS is the practice of DC, a UK based systems architect and solutions expert across PHP, Python and multiple frameworks, with a speciality in ecommerce. I build full platforms, SaaS, integrations and AI systems, and audit what you already have, scoped and fixed price before anything starts.
- 18 years
- 16 sectors
- PHP · Python · JS · TS
- UK based
What I do
Deep expertise, end to end
One person across the whole job. The same head on the audit, the build, the integration and the call about what to do next.
Software and ecommerce builds
Stalled build or no start line? I take it on, end to end.
Ecommerce on Shopify, Magento / Adobe Commerce, WooCommerce, PrestaShop, BigCommerce, headless and custom, plus SaaS platforms, modules and the core infrastructure underneath. PHP and Laravel, Python and Django, TypeScript and Next.js.
Fixed price, from a £500 health check on one topic up to a £3,000 complete audit. Speed, findability, product pages, checkout, AI visibility and the code underneath, each finding tied to the page it was seen on. You get what is wrong, why it matters, and the order to deal with it.
AI and automation
AI on the busywork, not a bet on the wrong tool.
How to make a Shopify store citable by ChatGPTAI systems and workflows that take the menial, everyday tasks off your team, so their time goes back to the work that moves the business.
Fractional / interim CTO
Senior direction, no full-time salary.
Fractional vs interim CTO vs lead developerPart-time senior technical leadership: direction, architecture, roadmaps and rescuing projects that have drifted. Bring me in as your interim CTO or systems architect, without a full-time hire. Scoped month to month, with a clean handover if it ever stops working for you.
Mentorship and AI upskilling
Your team, confident with AI, not a hiring spree.
Junior engineer mentorships, hands-on teaching, and AI upskilling sessions that get your people confident and productive with modern tools and AI.
Platforms and frameworks
The tools change with the job. These are the ones I reach for most.
What I fix
The problems I get called in for
Real jobs, in plain words. If one of these sounds like your project, it is worth a call.
A project that has drifted for years
A build has run for two years with no end in sight. I step in, set a clear goal and get it shipped.
Adding a new payment gateway
You need a new payment provider live in your platform. I build the integration, and can introduce you to the right gateway partners.
Email marketing integration
Connect your Laravel, Django or ecommerce system to Klaviyo, Mailchimp or your ESP, so campaigns run on real, live data.
PIM, ERP and system integrations
Your platform needs to talk to a PIM, ERP or other system. I build the integration so data flows cleanly both ways.
Fraud hiding in your orders
I analyse your order history to find fraud patterns and loopholes, then close the gaps they slip through.
Slow site, failing Core Web Vitals
Your site loads slowly and fails Google's Core Web Vitals. I make it fast, so you keep your rankings and your sales.
Conversion and UX that underperform
Traffic comes but does not convert. I audit conversion and UX, then fix what is quietly costing you orders.
Invisible to search and AI
I run SEO, AI and GEO audits so your site gets found by Google and by the AI tools people now buy through.
Shopify, ChatGPT and Perplexity →Releases that keep breaking the site
Every update takes something down. I add real testing and safe deploys, so changes stop breaking things.
Menial tasks eating the day
The repetitive admin pulling your team off real work, handed to AI workflows that just get it done.
No senior tech lead
You need CTO-level direction but cannot justify a full-time hire. I lead your tech part-time and set the roadmap.
Which CTO hire you actually need →An idea with nowhere to start
You have a platform or SaaS idea and no way in. I design and build the whole thing, from first line to launch.
Audits
Ecommerce audit pricing
Fixed prices, quoted before anything starts. No day rates and no open-ended scope. Every audit begins with a health check on one topic, then goes as deep as the access you give it allows. Shopify, Magento, WooCommerce, headless and custom builds.
Health check
One topic · no access needed
Nine pages on one subject, in plain English, written for somebody who does not work in technology. You pick the topic and the whole report goes to it, because one thing looked at properly tells you more than six of them skimmed.
- Speed
- Findability
- Product pages
- Basket and checkout
- AI visibility
- Trust and legal
Visual audit
Black box — no logins needed
What a customer, a search engine or an AI assistant sees, and nothing more. Every page template crawled on a laptop and a phone, speed measured per template, and your competitors measured the same way on the same day. No logins or code access needed.
Backend audit
Grey box — read-only access to your accounts and code
Read access to your accounts and your code. Google Ads, analytics, Tag Manager and Merchant Center checked against what the site actually does, which is where a finding stops being an opinion and gets a number against it.
Backend audit
White box — full access, nothing hidden
Everything in the grey box audit, plus the infrastructure underneath: hosting, caching, server response and how the database behaves under your slowest pages.
Complete audit
White box + performance — the deepest guarantee
The visual and white box audits together, plus a dedicated performance workstream: Lighthouse per template, request waterfalls, image delivery, caching and the queries behind your slowest pages. Bought separately the first two come to £2,450.
Workflow audit
Not yet available
How the business runs behind the site: the path an order takes, how product data reaches the page, and whether your lead times are accurate. Not quoted until it can be described exactly.
Black box, grey box and white box are the standard terms for how much access a tester is given: black box sees only what the public sees, white box sees everything including the servers. All figures exclude VAT. An audit tells you what is wrong, why it matters and what order to deal with it in. Carrying out the work is quoted separately once you have the report. For a platform move, see what an ecommerce replatform actually costs in the UK in 2026.
Tools I build in the open
keel
An open-source dev environment builder for any stack. One command scaffolds a full, working local setup: framework, services, tests and deploy config, all wired together and ready to run.
I build my tools in public, because the work should speak for itself. keel is free, MIT licensed and on GitHub.
$ keel new my-shop scaffolding stack... [ok] framework, services, tests [ok] deploy config written ready in 40s $ docker compose up
Questions
Straight answers
The questions people actually ask before they book. Prices match the audit menu on this page.
How much does an ecommerce audit cost?
- Fixed prices from a £500 health check on one topic up to a £3,000 complete audit. VAT is extra. The menu on this page is the live price list.
Do you work as a freelance PHP or Python developer?
- Yes. Freelance and contract, in PHP, Python and the frameworks those jobs actually use: Laravel, Django, Next.js, plus Shopify, Magento and WooCommerce when the store is the job.
What is the difference between a fractional CTO and an interim CTO?
- A fractional CTO is part-time leadership on a retainer. An interim CTO is a full-time stand-in, usually for months not years. A lead developer is a hands-on hire. The three get mixed up, and the cost gap is large. The 2026 UK numbers are in the article Fractional CTO, interim CTO, or lead developer. Read the article.
Do you work with Shopify and Magento?
- Yes. Shopify, Magento / Adobe Commerce, WooCommerce, PrestaShop, BigCommerce, headless and custom. Builds, audits, integrations and the rescue jobs when a project has drifted.
Get in touch
Let's talk about your project
Tell me what you are building and where it is stuck. If I can help, I will say so. If I cannot, I will point you to someone who can. Every call is free.
Prefer to message first? Find me on LinkedIn, follow the COULLWORKS page or see the open source on GitHub.
COULLWORKS is spelled with a double L. It comes from my surname, Coull. The GitHub organisation of the same name is where I publish the open source side of the same practice.