34 Express.js interview questions

Building web or mobile applications? Need an Express.js expert for your team?

We have good news for you: Long hiring times and or costly mis-hires don’t need to be a major concern. 

Testing Express.js skills is an important step, but the process can be easy – simply test them using our Express.js test and conduct interviews with your best talent.

“But which interview questions should I ask?” we hear you ask.

If you’re unsure, consider the 34 Express.js interview questions listed below in this article. Read until the end for some tips on how to do skill testing, as well.

11 general Express.js interview questions to ask applicants

Ask your talent some of these 11 general Express.js interview questions to gauge their general knowledge of Express.js.

1. Explain what Express.js is.

2. Name some of the unique Express.js features.

3. Explain whether Express.js is used in frontend or backend development.

4. Why do engineers use Express.js?

5. How is Express.js different from Node.js?

6. Explain whether MVC frameworks other than Express.js support scaffolding.

7. How is Express.js different from Django?

8. Does Express.js support any template engines?

9. Which skills and knowledge are essential for Express.js engineers?

10. Which soft skills are essential for Express.js engineers?

11. As an Express.js engineer, which skills are you looking to improve and how?

5 general Express.js interview questions and answers to assess your talent

Here are the answers to the five most critical general Express.js interview questions to help you review your talent’s responses.

1. Name some of the unique Express.js features.

Your applicants should know some of the features that make Express.js unique. They may mention some of the following points:

• Engineers can design single- and multi-page applications using Express.js

• Express.js supports various databases such as RDBMS and NoSQL

• Engineers can dynamically render HTML pages with arguments and templates

2. Explain what Express.js is.

Can your applicants explain what Express.js is? They should be able to explain that it’s an open-source, backend framework that’s used with Node.js and is ideal for building hybrid applications, single- and multi-page applications, and APIs (application program interfaces).

3. Which skills and knowledge are essential for Express.js engineers?

Some of the essential skills engineers need to use Express.js efficiently include knowledge of databases like SQLite (which you can assess with our SQLite test) and Node.js skills (which you can test with our Node.js test).

4. Which soft skills are essential for Express.js engineers?

Applicants should know which soft skills are essential for Express.js engineers.

They should also be able to name a few critical soft skills, including time management (which you can assess with our Time Management test) and communication skills (for which you can test with our Communication test).

5. As an Express.js engineer, which skills are you looking to improve and how?

Are your applicants keen to keep improving their skills?

Whether they’re working on their technical skills such as JavaScript coding (which you can assess with our JavaScript skills test) or problem-solving skills, ensure your candidates are interested in learning new skills and honing existing ones.

13 Express.js interview questions about technical definitions

Ask your applicants some of these 13 Express.js interview questions about technical definitions to learn whether their expertise matches your job requirements.

1. Which extension is used to save programs in Express.js?

2. Explain what scaffolding is in Express.js.

3. What is middleware in Express.js, and what does it help achieve?

4. What is application-level middleware?

5. What is router-level middleware?

6. What is error-handling middleware?

7. What is built-in middleware?

8. What is third-party middleware?

9. Explain what the express application generator does.

10. Explain what dynamic routing is in Express.js.

11. Name some database integrations supported by Express.js.

12. Name a type of web application engineers can build with Express.js.

13. Explain what HTTP methods are in Express.js.

5 Express.js interview questions and answers about technical definitions

Here are the answers to five of the vital Express.js interview questions about technical definitions to help you gauge your applicants’ knowledge and understanding of the framework.

1. Explain what scaffolding is in Express.js.

Can your applicants explain that the scaffolding technique involves making an application’s skeleton structure?

Do they know that it simplifies creating public directories and makes it easier to add middleware so they can begin building an application easily?

2. Name some database integrations supported by Express.js.

Some of the database integrations your interviewees may mention when responding to this Express.js interview question include RDBMS, SQLite, and NoSQL. Express.js supports other database integrations, including Cassandra, MySQL, and MongoDB.

3. What is middleware in Express.js, and what does it help achieve?

Applicants may explain that middleware in Express.js is a function that the Express routing layer invokes before the final request handler.

Are your interviewees also aware that middleware functions facilitate code execution, alter requests and response objects, and terminate the request-response cycle?

4. Which extension is required to save programs in Express.js?

Do your interviewees have the technical knowledge related to extensions in Express? Can they explain that they can save an Express.js program using the .js extension?

5. Explain what dynamic routing is in Express.js.

Shortlisted applicants with extensive knowledge of Express.js should know that dynamic routing involves moving from one page to another depending on the client’s request. It works by passing a parameter in a URL or using parameterized URLs to determine how to identify the path.

10 Express.js interview questions related to processes

Ask your candidates some of these 10 Express.js interview questions about processes to learn more about how they work and use their Express.js knowledge to complete tasks.

1. Explain how you would enable debugging for an Express.js application for Linux.

2. Explain how you would enable debugging for an Express.js application for Windows.

3. Explain how you would allow CORS in Express.js.

4. How would you manage error handling using Express.js?

5. Which code would you write to serve static files in Express.js?

6. How would you render plain HTML in Express.js?

7. How would you install Express.js?

8. When would you use app.use() in Express.js?

9. How would you make an HTTP server with Express.js?

10. How would you configure properties in Express.js?

5 Express.js interview questions and answers related to processes

Here are the answers to the five most crucial Express.js interview questions and answers related to processes. Use these to assess your applicants’ approach to tasks.

1. How would you manage error handling using Express.js?

Applicants may describe a few necessary steps they would follow to manage error handling in Express.js.

Some of the vital steps they may mention include:

• Creating a middleware

• Installing an error handler middleware

• Creating a variable 

• Using the middleware and the variable to manage the error

2. How would you render plain HTML in Express.js?

If your applicants are confident they can use Express.js well, they should know how to render plain HTML in Express.js.

Candidates may first mention that the res.render() function isn’t required. Instead, with a specific file, engineers can use a function known as the res.sendFile(). Applicants may also explain that they can use Express.js if the many assets are served with the directory.static() function. 

3. When would you use app.use() in Express.js?

Can your applicants explain that app.use() is a function for writing middleware in Express.js or for serving static files?

They may also briefly explain how app.use() works. For example, they may mention that app.use() also has one string parameter that engineers can use as an optional path and one callback parameter that they must always use.

4. Explain how you would enable debugging for an Express.js application for Windows.

Since there are different methods for enabling debugging for each operating system, applicants should be able to distinguish between Windows and Linux. They may explain that for Windows, engineers use the following command to enable debugging for an Express.js application in Windows:

Set DEBUG=express:node application.js

5. How would you install Express.js?

Since Express.js can run on a Node.js runtime environment, applicants should know that additional software is not required to install it. All that’s necessary is to install it as a module and run the Express.js module by entering the following command:

npm install Express –save 

5 recommendations to identify expert Express.js applicants using skills testing and interview questions

To help you evaluate your Express.js applicants with skills testing and interview questions, we have prepared 5 simple tips you can read below.

Finding the best talent doesn’t have to be complicated if you’re using the right methods.

1. Make skill testing your priority and use it early in the recruiting process

It’s tempting to look at every resume that comes your way when hiring an Express.js applicant, but this isn’t necessary – and opens the door to hiring bias. 

If you want to know whether your applicants have the Express.js skills you need, make skill testing your priority and use it early in the hiring process.

TestGorilla is a great option that can easily replace resume screening, so use our Express.js skills test to make more objective hiring decisions and hire faster. 

2. Follow a repeatable structure for all applicants

The recruitment and interview structure you follow should be identical for all applicants.

Begin with a technical skill screening using a skills test to shortlist your best applicants, invite them for an interview with a hiring manager, a second round of interviews if necessary, and then decide which candidate to hire.

The interviews themselves should also be structured: Use the same questions for all applicants in the same or similar order to compare responses easily and minimize bias.

3. Be mindful of the seniority level required for the job and adapt your questions to it

Knowing the seniority level that candidates should have to be successful at the job is critical.

Are you hiring a senior Express.js engineer or a junior one who’s just starting out? Knowing this will help make sure you select the right Express.js interview questions for candidates. 

4. Explain which technologies and skills are essential and ask about the applicants’ experience

As a hiring manager or recruiter, you should mention which technologies and skills are essential – ideally, in the job ad. For example, it might be essential that your applicants understand MySQL. You can discuss the details of these requirements during interviews, too. 

You can ask about your applicants’ experience, past roles, and side projects. Consider whether their experience matches your Express.js engineer role, and then proceed with higher-level interview questions about processes or technical definitions. 

Remember to take notes during the interviews to facilitate the assessment process.

5. Evaluate all the responses of your interviewees

Evaluating skills objectively doesn’t have to be difficult.

If you’re using skills testing, candidates’ scores will give you an accurate idea of their knowledge. TestGorilla automatically calculates results, which makes comparing candidates and evaluating their skills extra easy for you. 

As for the interviews, taking notes is essential because it enables you to compare candidates and see who has the best potential to succeed at the job. 

To review interview responses, share the notes you’ve gathered with the rest of your hiring team and compare everyone’s observations.

Don’t forget to consider soft skills and candidates’ motivation and cultural alignment, which can also contribute to your hiring decision.

Hire top Express.js experts with Express.js interview questions and skills tests

When you’re ready to start looking for your next Express.js expert, remember that screening resumes is not a must. You can use our Express.js skills test instead to make this process easier.

You’ll be able to hire a top Express.js applicant easily if you follow the right steps and use the right assessment methods, such as TestGorilla’s Express.js test and the right interview questions, which you can find in this article. This will enable you to evaluate your candidates objectively and without bias. 

 Register for free today and start making better hiring decisions, faster and bias-free.