How to Prepare for a Tech Test - Web Developers

So, you've scored a live tech test, and now you are hit with a mix of excitement and fear.

But don't panic! Like any art, the art of acing a tech test can be mastered.

Here at Codú, we're all about making the intricate simpler.

Let's get cracking!

Soft Skills & The Dance of Problem-Solving:


Interviewers want to understand how you think as you code, narrate.

Explain what you are thinking and doing. It's not natural, but without communicating, interviewers are left guessing what you are thinking or your approach.

Mock Interviews:

A Google search will help you find professional services to do mock interviews, but you can also reach out to people you might know in the industry to help you out.

Join a coding community and see if you can get someone's time to give you a mock interview so you can start to fail (and succeed) in private.

Problem-Solving Approach

Slow down! Too many people code before they think. Get used to the habit of understanding the problem first, thinking through potential solutions, and then coding.

Technical Proficiency

Algorithms & Data Structures

The Classic and usually the most stressful topic to be grilled on. I've never met someone who loved them, but this is foundational in tech interviews.

Practice problems on platforms like:

Frontend Developers


Deep dive into all things JavaScript! Be prepared to answer questions about hoisting, closures, promises, and the event loop.

The two greatest resources I know for learning JS in depth are You Don't Know JS and JavaScript the Hard Parts.

Know your array methods like map, filter, and reduce. With those, you can solve a lot of problems.

CSS Conundrums

With Flexbox and Grid layouts, you should be able to solve any layouts. Know them well, and if you aren't feeling confident, you can learn them here with a game:

For practical experience to learn from, I always recommend brushing up with some Frontend Mentor challenges.


Are you Team React? Team Vue? Or Team Angular? Whichever you pledge allegiance to, know it inside out.

You might be asked to build an application, fix an application or even the theory around your favorite framework so don't forget to brush up on your knowledge here.

Backend Developers


Brush up on languages you're using (e.g., Node.js, Python, Java, etc.). Be prepared to solve problems in your chosen language without Google. So brush up on anything that might throw you on the day.


Understand SQL queries, database design, and the differences between NoSQL and SQL databases.


The puppeteer behind your app show? Understand its mechanics. Make sure you understand how your apps and frameworks run on the server.

There's a whole host of backend interview topics that will be more job-specific, so it's absolutely crucial you ask questions upfront to know where to best spend your time.

To the Full Stack Heroes

Not all Full-stack roles are equal!

They usually have specific areas of expertise that they are looking for, so yet again, to prepare well, it's absolutely crucial you ask questions upfront to know where to best spend your time.

General Tips

Ask questions before your interview

Not all companies will ask algorithm questions, give a take-home test, or even get you to code live.

So what's the best way to be ready?

If you get contacted about an interview, always ask people what to expect from the interview. It's the best way to stop you from spending hours on the wrong things.

Here are some of the questions you should always ask:

  • "Could you tell me what steps are in the interview?"
  • "Will there be a take-home test"
  • "What's the format? Is it a live coding challenge? If so, is it algorithms, or what should I brush up on?"
  • "What tools do you use for the tech test, is it something like HackerRank?"

Knowing these things ahead of time will help you focus and make sure that you can test the coding environment ahead of time (if it's an online tool).

Rest well

Don't cram! Before the day of the test, ensure you're well-rested. Sleep will make you think much clearer than a late night of study.

Research the company

Check out sites like Glassdoor, where you might be able to find some of the interview questions ahead of time.

Know what the company does and always have a handful of questions to ask your interviewer (it helps you sound more interested).

Feedback Loop

After each test or interview, jot down the areas you felt less confident in and then study those areas.

Final Checks ✅

Set up your coding environment before the test. If they use a specific platform or tool, familiarize yourself with it.

Have a reliable internet connection and a backup plan if possible. I always have my mobile hotspot on just in case I need to switch to the backup internet.

Remember, tech tests aren't just about the code; they're about the coder. You are human, and you're not meant to be perfect!

Don't let a bad experience or a bad day dent your confidence.

Stay calm, think critically, and good luck!

If you have any resources that you think are a must-have before interviews, let me know in the comments. ✌️

Avatar for Niall Maher

Written by Niall Maher

Founder of Codú - The web developer community! I've worked in nearly every corner of technology businesses; Lead Developer, Software Architect, Product Manager, CTO and now happily a Founder.


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