Custom Add-on Development & Maintenance

Many ExpressionEngine and Craft CMS sites that have been running for a number of years contain bespoke add-ons and custom integrations that are central to how the site works. These are often the pieces of functionality that no off-the-shelf solution could provide, and they frequently need maintaining, updating and extending as the business evolves.

Karl Bowers has been building and maintaining custom ExpressionEngine and Craft CMS add-ons since 2007. He regularly inherits bespoke codebases built by previous developers and takes responsibility for keeping them running and improving them over time.

What this service includes:

• Maintenance of existing custom add-ons, keeping them compatible with current versions of ExpressionEngine or Craft CMS.
• Extension of existing functionality, adding new features to custom add-ons that have been in place for years.
• New custom add-on development where off-the-shelf solutions do not meet the requirements of the site or the business.
• Third-party integrations, connecting ExpressionEngine or Craft CMS to external systems such as CRMs, ERPs, payment platforms and APIs.
• Code review and refactoring of inherited custom add-ons to improve reliability, security and performance.
• Documentation of custom add-on functionality so the system is properly understood and maintainable long-term.

Common questions:

Can you maintain a custom add-on built by a previous developer?

Yes. This is one of the most common types of work Karl takes on. Most custom add-ons can be understood and maintained regardless of who wrote them, though some require more initial investigation than others. Karl will give an honest assessment after reviewing the code.

Our custom add-on is not compatible with the latest version of ExpressionEngine, can you fix that?

Yes. Rewriting custom add-ons for compatibility with newer versions of ExpressionEngine or Craft CMS is a routine part of the upgrade work Karl carries out for clients.

How do you price custom add-on development work?

Most custom development work is quoted on a fixed-price basis once the requirements are clear. For ongoing maintenance or work with a less clearly-defined scope, Karl can work on an hourly or retainer basis. He will discuss the best approach based on the nature of the work.

How long does it take to build a new custom add-on?

It depends entirely on the complexity of what is required. A simple add-on with straightforward functionality can be delivered in a few days. Complex integrations or feature-rich add-ons take longer. Karl will give a realistic timeline as part of the initial scoping process.

Can you integrate ExpressionEngine or Craft CMS with an external system we use?

Yes. Karl has built integrations between ExpressionEngine and Craft CMS and a wide range of external systems, including CRMs, ERPs, stock management platforms, fulfilment systems and custom APIs. If the external system has an API, an integration is generally possible.

What if the original developer of the add-on is not available to answer questions?

Karl is used to working without access to the original developer. Where there is no documentation, he works through the code directly to understand how it functions. This takes more time initially but results in a thorough understanding of the system.

Can you add new features to a Craft CMS plugin we already have?

Yes. Extending existing Craft CMS plugins is straightforward in most cases. Karl will review the existing plugin, understand how it is structured, and discuss the most practical way to add the new functionality.

Do you provide documentation and source code when the work is complete?

Yes. All custom work includes documentation of what has been built and how it works. Source code is provided and clients retain full ownership of anything developed for them. Karl encourages proper documentation as a matter of principle, not just good practice.