Every theme developer should be able to answer most, if not all, of the following questions. Let me know if I’ve missed anything obvious. This was a quick mind dump.
If you plan on hiring a theme developer at your organization, ask some of these questions. They matter.
- What are the primary differences between theme frameworks, starter themes, and parent/child themes?
- What primary languages make up WordPress themes?
- What is template hierarchy?
- What are custom post types?
- Are custom post types more appropriate in themes or plugins? Why?
- What are post formats?
- What is the GPL? What are its primary freedoms?
- Does the GPL require you to give away your themes at no cost?
- What practical implications are there in using GPLv2 versus GPLv3 licensing for a theme?
- At a minimum which files are required for a functional theme?
- Are themes required to be 100% GPL?
- What are template parts?
- What is The Loop?
- What practical considerations should be taken into account when creating a post editor stylesheet for a theme?
- What is RTL? What are two primary ways of RTL’ing a theme?
- What’s the best way of implementing scripts and styles in a theme?
- What’s the best way of implementing non-standard fonts in a theme?
- What is infinite scrolling? Are you in favor of it or not? Why?
- Do you prefer
px
units orrem
units? Why? - What is debouncing in JavaScript?
- What is throttling in JavaScript?
- Explain theme internationalization.
- Explain your favorite methods for debugging themes.
- What are transients and give an example of how they’d be used in a theme.
- What is prefixing? Why is it important?
- What are hooks? What is the difference between actions and filters?
- What is a theme setup function?
- What’s your favorite template tag? Least favorite? Why?
- Explain sanitation and validation.
- What drawbacks are there to the Customizer-only approach for theme options?
- What do you hate most about WordPress themes? How would you fix it or how are you getting around it?
- What practical implications should theme developers keep in mind on theme switch?
- What performance considerations should be taken into account when developing themes?
- What SEO implications should be taken into account when developing themes?
- Give an example of what you feel is trivial post meta versus non-trivial post meta.
- Should theme screenshots reflect themes at their best or themes immediately post-activation? Why?
- What standardized theme hooks would you like to see added into WordPress?
- What are page templates?
- Explain the differences between how themes treat “home pages” versus “front pages”.
- What makes a theme premium? Why?
- What one thing do you wish were baked into WordPress that would make themers’ jobs easier to do?
- Explain a few differences between
postMessage
support andrefresh
within the Customizer. - How do you prefer to deal with featured images in singular versus non-singular views?
- Explain theme mods.
- Explain a few methods for making themes more accessible.
- How would you improve the WordPress theme taxonomy?
- Explain how content width is handled by themes.
- What’s your favorite theme? Why?
- Where’s the first place you look for answers when building themes?
- What does it mean when we say that a function is pluggable?