The title of this post is not really accurate, but I can’t think of another way to say it. This post is related to my earlier one on what a Drupal Developer does day-to-day. Here, I will talk about some of the skills required of a Drupal developer. I am not aiming for completeness in this post (that’s a goal for another time) but I will try to list all skills required to build a regular Drupal site, deploy it, and keep it running. Some of these skills are foundational whereas others may be only needed for specific requirements. Moreover, not all skills are required at a high expertise level. For some roles, even awareness is enough.

This post would be useless without a target persona. Different organizations have different needs and what works at one organization may not work at another at all. Similarly, different roles within an organization have different needs. For example, at Axelerant, we do not have a dedicated site-builder role but this is something that is expected of a Drupal Developer. Such an arrangement may not work at all for your organization nor can I say this arrangement will work forever for Axelereant. In fact, it is even weird to use the word “forever” here.

The target persona for this post is a Drupal Developer building sites and functionality for a complex Drupal website with rich content, workflows, editorial customizations, varying layouts, and more features typically found in a modern content-rich website. Since this is Drupal we are talking about, the above definition is actually quite broad. It includes a web presence for organizations from publishing, healthcare, higher-education, finance, government, and more. With that settled, let’s look at the skills.

Site-building

A Drupal developer would need to have the following skills related to site-building. Even if a developer does not build sites, there is a good chance they would be interfacing with these aspects from code. Hence, most of these are foundational.

• Content modelling: Understand what makes a good content structure for a site. You should be able to determine if the content structure you are building is the relevant one for the requirements.
• Content moderation: Most sites need this. I have seen this being used even on simple sites when there is more than one type of user. Understanding how the moderation workflow works and how it ties with the entity-field structure along with its revisions is important.
• Multiple languages: It is important to understand how Drupal implements multilingual functionality at both interface and content (translation) level. Depending on the requirements, certain aspects of how translated content is stored in fields could be very relevant. At a basic level, you should also be aware of how Drupal determines the language when it renders a page or response.
• Configuration Management: While this may seem more to do with developers, it is important to understand this from a site building perspective. You need to understand how the content types you create are stored in configuration and how is it different from how, for example, site information is stored. This means you need to understand configuration entities and simple configuration. You also need to understand how configuration can be changed depending on the environment and how it could be overridden.
• Common solutions like views and webforms: Before you set about developing for some functionality, you have to make sure if there is a solution out there already. You also need to know how to pick modules for your problems.

Development

I don’t think this section needs any explanation as the entire post is about this. So let’s jump in.

• PHP: This might seem like a no-brainer. Drupal is written in PHP so it is a good idea to be very comfortable with PHP. Understand object-oriented programming, how Drupal uses different constructs such as traits. Also, understand patterns such as dependency injection and observer pattern (hooks and event subscribers are based on this). Then, keep up with what’s new in PHP, if possible, and use it.
• Composer: Arguably, this is a part of site-building as well but there is a good reason to keep it here. Apart from using composer to download modules, understand how it helps in writing the autoloader. Also, understand how composer works to select a module or a package and what are the reasons it might fail. Most of this comes with experience.
• Caching: This is probably the most important part to understand about Drupal. Caching is deeply ingrained at multiple levels in Drupal and it is important to understand how it works. Almost all your code will need to interact with it even if you aren’t planning to cache your responses.
• Other Drupal API’s: There are some common API’s you should be familiar with; for example, Form API and Entity API come to mind. But also be aware of other API such as Batch, Queue, plugins, Field, TypedData, etc. You should know where to look when you need it for a problem.
• Automated testing: The Drupal core has a very vast collection of test cases and that means you may only have to write functional test cases for your site. You should understand the different tools that you can use to write them.

Deployment

You have to understand where your site is going to live to build it well. We don’t live in that age where you would write code and throw it over a wall to the ops team for them to deploy it. You may not be deploying it but you have to understand the concepts.

• Servers: Understand how servers work. You don’t need to know enough to configure one securely (unless that’s your job) but you should know enough to understand the terms. For example, you should know what are the common web servers and how they may be configured to run PHP. Also, understand what kind of configuration Drupal needs to run.
• High Availability: Given Drupal’s market, there is a good chance that the site you are building will need to run in a highly available environment. Understand what it means and what that implies for your Drupal site. Most of these issues may be resolved for you if you are using one of the PaaS providers but if you are building your own server(s), you should understand how to configure Drupal to run on multiple servers. Even if you are using PaaS, you should still understand how running on multiple servers could affect how you write code, e.g., how you work with temporary files.
• CI/CD: Continuous Integration is very common today and it is important you understand it to be a productive developer. There are dozens of solutions to choose from and most have some kind of a free offering. Pick one and try it out.

And more…

Like I said before, I am not aiming for completeness here but only in making a start. Please let me know if I have missed something obvious. Given the nature of these posts, I can only spend 1-2 hours planning and writing these, so there is a very good chance I have missed something. Let me know.