9 More Things to Know If You Are a Drupal Developer

So, you're a Drupal developer. You've built themes, wrangled modules, and navigated the complexities of nodes, views, and taxonomies.

You're comfortable in the ecosystem. But in a landscape where technology evolves at lightning speed, comfort can be a career-killer. The difference between a good Drupal developer and a great one-the kind that CTOs trust with enterprise-level projects-lies in mastering what comes next.

This isn't another beginner's guide. This is for the developer who is ready to level up. We're diving into nine critical areas that separate the architects from the assemblers in the Drupal world.

These are the concepts that will not only make you a more effective developer but will also future-proof your skills for years to come. Let's move beyond the basics and explore the topics that define modern, high-performance Drupal development.

1. Composer is Your Co-pilot, Not Just a Package Manager

Many developers use Composer to `require` a new module and call it a day. An advanced developer understands that Composer is the backbone of a modern Drupal project.

It's about more than just downloading code; it's about managing the entire dependency tree of your application, including Drupal core, contributed modules, and third-party PHP libraries.

Why it matters:

1. Predictable Builds: The `composer.lock` file ensures that every developer on your team, as well as your deployment pipeline, is using the exact same version of every dependency.

   This eliminates environment-specific bugs.

2. Patch Management: Using tools like `cweagans/composer-patches`, you can apply critical patches to modules without hacking the core code, keeping your project maintainable and update-friendly.
3. Scaffolding and Scripts: You can automate project setup, like placing specific files in the right directories or running post-update scripts, directly from your `composer.json` file.

Treating Composer as a fundamental part of your architecture, not just an installation tool, is a hallmark of a senior developer who builds robust, scalable applications.

2. Think API-First: Drupal as a Content Engine

The web is no longer just about websites. Content needs to be delivered to mobile apps, IoT devices, digital kiosks, and single-page applications (SPAs).

An API-first approach means you design your content structures in Drupal with the primary goal of exposing them through an API. The website itself becomes just one of many consumers of that API.

Drupal's core REST, JSON:API, and contributed GraphQL modules make it an incredibly powerful headless content management system.

Key Takeaway: Stop thinking of Drupal as just a website builder. Start seeing it as a structured content repository that can power any digital experience you can imagine.

This mindset is crucial for building future-ready applications and is a highly sought-after skill in the Open Source Development landscape.

3. Embrace Decoupled (Headless) Architecture-Strategically

Going hand-in-hand with the API-first mindset is the ability to implement a decoupled architecture. This is where the back-end (Drupal) is completely separate from the front-end (e.g., a React, Vue, or Next.js application).

However, a senior developer knows this isn't a silver bullet. You need to understand the trade-offs:

When to Go Headless: A Quick Checklist

A fully decoupled approach means losing some of Drupal's powerful built-in features like Layout Builder and in-place content previews.

The expert knows when a fully decoupled, progressively decoupled, or traditional monolithic approach is the right tool for the job.

4. Master the Configuration Management Workflow

If you've ever found yourself making configuration changes (like adding fields or changing view settings) directly on a production server, you need to master the configuration management workflow.

Drupal's system allows you to treat your site's configuration as code.

A professional workflow looks like this:

1. Local Development: Make configuration changes on your local machine.
2. Export: Use Drush (`drush config:export`) to export these changes into YAML files.
3. Commit: Add these YAML files to your Git repository.
4. Deploy: Push your code to the staging or production environment.
5. Import: Use Drush (`drush config:import`) to apply the changes from the YAML files to the live database.

This ensures that every configuration change is version-controlled, reviewed, and deployed in a predictable, automated way.

For complex team environments, using modules like Config Split allows you to manage different configurations for different environments (e.g., enabling development modules locally but not in production).

5. Become a Drush and Command-Line Wizard

The Drupal admin UI is powerful, but the command line is where efficiency lives. Drush (the Drupal Shell) is an indispensable tool for any serious developer.

While many know the basics like `drush cr` (cache rebuild), true mastery comes from using its full potential:

1. Database Operations: Quickly syncing databases between environments (`drush sql-sync`) or creating backups (`drush sql-dump`).
2. Code Generation: Scaffolding new modules and plugins with `drush generate`.
3. User Management: Running commands to add roles, reset passwords, or impersonate users (`drush user:login`).
4. Running Queues and Cron: Manually triggering background jobs for debugging and testing.

Proficiency with the command line demonstrates an ability to automate tasks, work efficiently, and manage complex sites without relying on a GUI.

6. Go Deep on Performance Optimization

Every developer knows to turn on caching. An advanced developer knows *why* it works and what to do when it's not enough.

Proactive performance optimization goes beyond the basics and involves a holistic approach:

1. Profiling: Using tools like XHProf or Blackfire.io to find the exact functions and database queries that are slowing down your site.
2. Advanced Caching: Integrating with external caching layers like Varnish or a CDN, and understanding cache tags for granular invalidation.
3. Database Tuning: Analyzing slow queries and ensuring proper indexing on large tables.
4. Front-End Performance: Optimizing image delivery, aggregating CSS/JS effectively, and leveraging modern standards like HTTP/2.

For any high-traffic site, performance is a critical feature, not a nice-to-have. Being the developer who can diagnose and fix performance bottlenecks makes you invaluable.

7. Treat Security as a Proactive Discipline

Drupal has a world-class security team, but they can't protect you from poor implementation practices. A secure mindset means more than just applying security updates promptly.

It involves:

1. Understanding the APIs: Using Drupal's APIs correctly to sanitize user input and prevent common vulnerabilities like Cross-Site Scripting (XSS) and SQL injection.
2. Access Control: Configuring roles and permissions with the principle of least privilege. Not every authenticated user needs access to everything.
3. Secure Configuration: Properly setting file permissions, protecting configuration files, and using SSL/TLS across the board.
4. Code Audits: Regularly reviewing custom code and third-party modules for potential security holes.

In an era of constant threats, being able to build and maintain a verifiably secure application is a top-tier skill.

8. Advanced Theming with Twig

Basic theming involves overriding templates and writing CSS. Advanced theming involves leveraging the full power of the Twig templating engine to create clean, reusable, and performant templates.

This includes:

1. Twig Functions and Filters: Using Twig's built-in capabilities to manipulate data directly in the template, reducing the need for complex preprocessing functions.
2. Macros: Creating reusable chunks of template logic, similar to functions in programming, to keep your code DRY (Don't Repeat Yourself).
3. Template Inheritance: Using `{% extends %}` and `{% block %}` to create a base template structure that other templates can build upon, which is far more powerful than simple includes.
4. Source and Embed: Understanding how to embed controller outputs or include templates while managing their context and variables effectively.

9. Contribute Back to the Community

Drupal is an open-source project, and its strength comes from its community.

Contributing back is not just altruism; it's a powerful career development tool.

How it helps you grow:

1. Deepens Your Knowledge: Working on a module or a core issue forces you to understand Drupal's architecture at a much deeper level.
2. Builds Your Reputation: Your Drupal.org profile becomes a public portfolio of your skills and expertise. It's one of the first places a potential employer or client will look.
3. Networking: You connect with and learn from some of the best Drupal developers in the world.

You can start small by helping with documentation, testing patches, or participating in issue queues. Every contribution matters and signals that you are not just a consumer of the technology, but an active participant in its future.

Conclusion: Evolving from Developer to Architect

The journey of a Drupal developer doesn't end with mastering the basics. The nine areas above represent the transition from simply building websites to engineering robust, scalable, and secure digital experiences.

By embracing Composer's full potential, adopting an API-first mindset, mastering configuration management, and making performance and security a core part of your workflow, you position yourself as a leader in the field.

These are the skills that not only solve complex technical challenges but also deliver immense business value. They are what companies look for when they need to hire a dedicated developer capable of steering their most critical projects to success.

This article has been reviewed by the Developers.dev Expert Team, comprised of certified solutions architects and senior software engineers with decades of experience in enterprise web development and open-source solutions.

Frequently Asked Questions

Is Drupal still relevant for developers to learn?

Absolutely. While the CMS landscape is diverse, Drupal remains a top choice for large-scale, content-heavy, and complex websites for enterprises, governments, and universities.

Its strengths in security, scalability, and content modeling are more relevant than ever. Furthermore, its evolution into a powerful headless CMS has opened up new opportunities for developers to use it with modern front-end frameworks.

What is the biggest difference between a mid-level and a senior Drupal developer?

A mid-level developer is typically proficient at executing tasks within an existing Drupal site: creating content types, building views, and theming.

A senior developer thinks at an architectural level. They understand the 'why' behind the 'what.' They can design a system from the ground up, make strategic decisions about architecture (e.g., monolithic vs.

decoupled), implement robust deployment workflows (configuration management), and proactively address performance and security.

How important is PHP for a modern Drupal developer?

PHP remains fundamentally important. Drupal is built on PHP, and its latest versions leverage modern PHP features and frameworks like Symfony.

While a front-end developer working on a decoupled site might not write PHP daily, any back-end developer, module developer, or full-stack developer needs a strong, modern understanding of PHP, including object-oriented principles, to be effective.

Can I be a successful Drupal developer without using the command line?

You can be a functional site builder, but you cannot be a modern, efficient Drupal developer without the command line.

Tools like Composer (for dependency management) and Drush (for site administration) are essential for professional workflows, automation, and performance. Avoiding the command line severely limits your efficiency and ability to work on complex, team-based projects.