I passed the Acquia Certified Developer exam for Drupal 10 in 2024. Here's an honest account of what the exam actually tests, what preparation worked, and what I'd do differently.
What the exam actually covers
The exam has roughly 60 questions across six domains. Based on my experience, the approximate weighting is:
- Fundamental Web Development Concepts (15%) — HTTP, REST, caching fundamentals
- Site Building (25%) — Views, content types, fields, display modes
- Front-end Development (15%) — Twig, theme hooks, libraries
- Back-end Development (25%) — Module development, hooks, plugins, services
- Performance and Operations (10%) — Caching layers, deployment, Drush
- Security (10%) — Input sanitisation, access control, CSRF
Don't underestimate Site Building. I expected the exam to be heavily weighted toward module development (since that's most of my day job) but site building and Views configuration questions were surprisingly common. Know Views inside out.
What to study
The Drupal documentation is the primary source. Focus on these specifically: the Plugin API, the Service Container and dependency injection, the Form API, the theme system and Twig, the cache API, and entity API. If you can explain how each of these works without looking it up, you'll pass.
Practice questions
Acquia provides a free study guide and practice questions. Do all of them, but don't stop there — the real exam has questions the practice set doesn't cover. Build a fresh Drupal 10 site from scratch and implement each concept from the study guide manually. Reading about hooks is different from writing them under time pressure.
The day itself
The exam is 90 minutes, online proctored. The questions are mostly scenario-based — "given this situation, which approach is correct" rather than "what is the exact syntax of this function." This rewards genuine understanding over memorisation, which I appreciated.
If you've been building Drupal sites professionally for more than two years and you understand the architecture, you can pass this with 2–3 weeks of focused preparation. Don't over-prepare — the opportunity cost of another month of study is real.