Question 1
Difficulty: medium
How do you approach building a custom WordPress theme from scratch, and what steps do you take to make sure it is maintainable and performant?
Sample answer
When I build a custom WordPress theme from scratch, I start by clarifying the content model, required templates, and key user journeys. I usually create a lightweight theme structure with a clean separation between templates, styles, and functionality, and I avoid putting business logic directly into template files. I rely on a modular approach so components like headers, cards, and CTA blocks can be reused across pages. Performance is a priority from the beginning, so I keep the CSS and JavaScript lean, load assets only where needed, and make sure images are optimized. I also pay attention to accessibility, responsive behavior, and semantic markup because those affect both user experience and maintainability. Before launch, I test across browsers, check for PHP or JavaScript errors, and review the theme against WordPress coding standards so future updates are safer and easier.
Question 2
Difficulty: medium
Can you describe a time when you had to debug a difficult WordPress issue in production? How did you identify the root cause?
Sample answer
In one project, a client reported that part of the site randomly stopped saving content in the editor. Because it happened inconsistently, I had to narrow it down carefully. I first reproduced the issue in a staging environment and checked browser console logs, PHP error logs, and server responses. That helped me see that a plugin conflict was causing an AJAX request to fail when a specific block pattern was used. I disabled plugins one by one and confirmed the conflict, then traced it to a script that was loading globally even though it was only needed on a single page type. I fixed it by limiting the script to the correct template, and I also added a fallback check so the editor would fail more gracefully if the plugin was active again. What I learned from that situation is that debugging WordPress often means looking at the full stack, not just the theme or plugin code.
Question 3
Difficulty: easy
How do you decide whether to use a plugin, custom code, or a custom plugin for a WordPress requirement?
Sample answer
I usually decide based on long-term maintainability, scope, and how unique the requirement is. If a well-maintained plugin already solves the problem cleanly and does not create unnecessary overhead, I am comfortable using it. If the requirement is very specific to the business, I prefer custom code or a custom plugin so the site is not tied to an overly broad third-party solution. I avoid putting reusable functionality inside a theme because that creates problems when the design changes later. For example, if a client needs custom post types, fields, or integration logic, I would typically build that in a dedicated plugin so it remains portable. I also think about performance, security, and support. A plugin may save time initially, but if it adds too much bloat or introduces update risks, custom development is often the better investment for the client.
Question 4
Difficulty: medium
How do you optimize a WordPress site for speed without breaking functionality?
Sample answer
My approach is to improve speed in layers so I do not trade performance for stability. I start by measuring the site with tools like Lighthouse or GTmetrix so I know what is actually causing the slowdown. Then I focus on the biggest wins first: image compression, proper image sizes, caching, and reducing unnecessary scripts and styles. On the development side, I make sure assets are loaded conditionally rather than everywhere, and I avoid heavy page builder features when a simpler component will do the job. I also check database-heavy queries, especially on archive pages or custom loops, because those can create hidden bottlenecks. If a plugin is causing front-end weight or slow queries, I look for a cleaner alternative. I test after every change to confirm the site still behaves correctly, because performance improvements are only useful if they do not introduce layout issues or broken interactions.
Question 5
Difficulty: easy
Tell me about a situation where you had to work with a designer or content team to deliver a WordPress project. How did you keep the work aligned?
Sample answer
On one project, I worked closely with a designer and content team to launch a marketing site with a lot of custom page sections. To keep everything aligned, I asked early for the design system, page hierarchy, and content structure rather than waiting until development was already underway. That helped me spot gaps, like sections that looked great visually but would be difficult to maintain with real content. I suggested small adjustments to spacing, heading styles, and component behavior so the design would hold up when content changed. I also set up regular check-ins and shared staging links so the team could review progress in context instead of relying on screenshots alone. When content changes came in late, I made sure the template structure was flexible enough to handle them without last-minute code rewrites. I find that WordPress projects go much more smoothly when developers, designers, and content owners communicate early and often.
Question 6
Difficulty: medium
How do you handle custom post types, taxonomies, and Advanced Custom Fields or similar field systems in WordPress?
Sample answer
I use custom post types and taxonomies when the content has its own structure and should not be forced into standard posts or pages. Before I build anything, I define how the content will be edited, filtered, and displayed on the front end, because that informs the data model. For field systems like ACF or similar tools, I try to keep the editor experience simple and predictable. That means grouping fields logically, using repeaters only when they genuinely help, and naming things clearly so content editors do not feel lost. I also think ahead about validation and fallback values, because content is rarely perfect. On the template side, I build output defensively so missing fields do not break the page. I like this approach because it gives editors flexibility while keeping the site structured and manageable for developers. It also makes future enhancements easier, since the content model is already organized.
Question 7
Difficulty: hard
What steps do you take to secure a WordPress website?
Sample answer
I treat security as part of routine development rather than something added at the end. First, I keep WordPress core, themes, and plugins updated, but I only use trusted plugins from maintainers with a strong track record. On the development side, I sanitize and validate input, escape output properly, and use nonces where appropriate to protect forms and actions. I also avoid exposing unnecessary information in error messages or debug output on production sites. Beyond code, I look at practical controls like strong admin passwords, limited user roles, two-factor authentication, and regular backups. If the site has custom endpoints or AJAX actions, I test them carefully because those can become weak points if they are not handled correctly. I also recommend restricting admin access when possible and monitoring logs for suspicious activity. In my view, secure WordPress development is a combination of good coding habits, sensible configuration, and ongoing maintenance.
Question 8
Difficulty: medium
How do you troubleshoot a WordPress site after a plugin update causes layout or functionality issues?
Sample answer
My first step is to confirm the exact change that caused the issue, because that helps me avoid guessing. I would check the update notes, compare the site behavior before and after the update, and reproduce the issue in staging if possible. Then I would inspect the browser console, network requests, and any PHP logs to see whether the problem is a script conflict, a CSS change, or a server-side error. If the site is visibly broken, I may temporarily roll back the plugin to restore service while I investigate, but only after making sure there is a backup in place. From there, I isolate whether the issue is caused by the plugin itself, an interaction with the theme, or another plugin. If there is no quick fix, I look for a safe workaround or patch. I always document what happened so the team has a clear record and future updates can be tested more carefully.
Question 9
Difficulty: hard
What is your experience with WordPress REST API or custom API integrations, and how do you use them in real projects?
Sample answer
I have used the WordPress REST API for projects where content needs to be displayed in a more dynamic way or consumed by another system. In practice, that might mean fetching posts into a custom front-end component, connecting WordPress to a CRM, or syncing data from an external service. My first priority is always to understand the data flow and failure points, because integrations can become fragile if they are not designed carefully. I pay attention to authentication, rate limits, and error handling so the user experience does not break when an external service is slow or unavailable. On the WordPress side, I usually create clean custom endpoints only when the built-in API does not cover the requirement well enough. I also test payloads thoroughly, because formatting issues and permission errors are common. I like API work because it makes WordPress more flexible without overcomplicating the site architecture.
Question 10
Difficulty: easy
How do you ensure that the WordPress sites you build are easy for non-technical clients or editors to manage?
Sample answer
I try to design the backend experience with the editor in mind, not just the developer. That starts with a clear content structure, sensible field labels, and templates that guide users rather than overwhelm them with options. I avoid making editors depend on fragile shortcodes or confusing page-builder layouts unless the project really calls for that level of flexibility. Instead, I build reusable sections and constrain choices where it helps prevent mistakes. I also think documentation matters a lot, so I provide short, practical notes for common tasks like updating banners, adding testimonials, or changing navigation links. If possible, I walk the client through the staging site before launch so they can practice editing content and ask questions while there is still time to adjust. My goal is always to leave them with a site they can confidently manage, because a WordPress project is only successful if the client can actually use it well after handoff.
