Craft CMS
What we do:
ExpressionEngine and Craft CMS, exclusively, since 2007. Version upgrades, long-term retainer support, taking over from agencies, third-party integrations including Stripe, Salesforce and HubSpot, and legacy PHP maintenance. Every project is handled personally by Karl. You deal directly with Karl, from first call to final delivery.
Platform
Craft CMS Maintenance, Upgrade & Support
Specialist support, maintenance, and upgrades for business-critical Craft CMS websites. Extensive hands-on platform experience, all work handled personally by Karl.
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Platform
ExpressionEngine Maintenance, Upgrade & Support
Specialist support, maintenance, and upgrades for business-critical ExpressionEngine websites. Close to two decades of hands-on platform experience, all work handled personally by Karl.
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Platform
Custom PHP & Laravel Development
Bespoke PHP application development and Laravel project work, from new builds and third-party integrations to extending and modernising existing custom-built applications.
Find out moreTrusted by established businesses and growing brands across the UK
Expression 37 works with a small number of clients at any one time. These are some of them.



What we have worked on:
Every client came with a real problem and a website they could not afford to have fail. Here are a selection of the engagements and what was involved in each.
Craft CMS
Custom PHP
City Permits
ExpressionEngine
Graham Sanderson Interiors
What we write about:
Practical writing on ExpressionEngine, Craft CMS, and the kind of problems that build quietly until they can no longer be ignored. Written for business owners, not developers.
Your Site Might Be Running Cloudflare and Getting Nothing From It
Plenty of ExpressionEngine and Craft sites have Cloudflare in front of them and get almost no benefit from it, because it was never configured for how the site actually works. This covers what Cloudflare should be doing for a business-critical site and what a proper setup involves.
Fixed Price or Retainer: Which One Protects a Business-Critical Site
Comparing quotes for ongoing website support usually means comparing two different pricing models: a fixed price for a defined piece of work, or a retainer that covers ongoing support each month. Business owners often pick based on which number looks smaller on the page, without weighing what each model actually protects against.
What an Outdated ExpressionEngine or Craft CMS Install Actually Exposes You To
An unpatched CMS install carries known, publicly documented vulnerabilities that no longer get fixed. What that risk actually looks like, and how to check where you stand.
About Karl
Karl founded Expression 37 in 2007 and has worked exclusively with ExpressionEngine and Craft CMS ever since. He does not take on work in other platforms and does not hand work to other developers. Expression 37 is deliberately small, because the kind of support that matters to clients with business-critical sites is specific to their site, not something that scales in the conventional sense. If you work with Expression 37, you work with Karl.
Find out how we workClient feedback:
It's always a nervous decision making the right choice of web provider when you have a large-scale project to be developed such as the York GPVTS website. Thankfully we made the right choice going with Karl at Expression 37. Karl has been excellent throughout the whole process of the project, working very closely with me and other members of the York GPVTS staff to ensure the site was built to our exact requirements. The end result has been truly impressive and we have had fantastic feedback from both internal staff and the specialist trainee doctors that use the site on a regular basis. Since the site has launched we have requested numerous development updates and modifications that are typically required of a project at this level. Karl has never failed to deliver these requests, often adding new ideas and suggestions to help improve the scope of our initial ideas. If you are looking for a solid, reliable, and friendly web developer, then Karl is your man!
Stuart Calder - GP Training Programme Director
NHS York GPVTS