A supervised technical test shows how a candidate writes code. An interview mostly shows how well they talk about it. If you use technical assessment hiring well, you use both, and you give each one the job it is good at.
This article covers what a test catches, what it cannot, and how to build a process around that. If you have an engineer to hire this month, it will save you a bad week or two.
What does a technical assessment actually test?
A good technical assessment gives the candidate a real problem for the role and asks them to solve it in code. It is not a quiz on trivia.
For a backend role, that might be designing a small API and handling bad input. For a data engineer, it might be cleaning messy data and building a reliable pipeline step. The point is that the task looks like the job.
The score then shows things you can compare across candidates:
- Does the code work?
- Does it handle edge cases, such as empty or broken input?
- Is it readable by someone else?
- How long did it take, and how did they spend the time?
Two candidates can sound equally sharp in a call. Their code often tells a different story.
What does a test catch that an interview misses?
Interviews reward people who explain well. That is a useful skill, but it is not the same as writing working software.
Here is what a role-specific test tends to surface that conversation does not:
- Fluent talkers who struggle to write code. They know the vocabulary, but stall when a blank editor is in front of them.
- Quiet candidates who write excellent code. Nerves or a different first language can hide real skill in a call.
- Shallow answers to deep problems. A test forces them to finish the work, not describe it.
- Consistency. Every candidate gets the same task, so you compare like with like. Interviews drift depending on who asks and how the conversation goes.
This is also why interviews run by one person are risky. Their mood, their favourite topics and their own biases all shape the result.
Why does supervision matter?
An unsupervised test only tells you how good the final answer is. It does not tell you who produced it.
A candidate can get help from another person, copy a solution, or lean on tools the test was never meant to allow. A good score then says little about their own ability.
Supervision fixes that. At Talent Navigator, the role-specific test is taken under camera supervision, so the score reflects the candidate's own work. That is the main reason we treat a supervised score as something you can trust before you spend an hour on a call.
If you are comparing tools, our guide on how to choose technical hiring assessment software lists what to check.
What can a test still not show?
A test cannot show how someone behaves when things are unclear or when they disagree with you.
It does not tell you how they react to a vague brief, whether they ask good questions before starting, or how they push back on a bad decision without starting a fight. It also says little about how they take feedback.
That is the one thing to keep for the human conversation. Ask about it directly:
- "Tell me about a time you got a brief that was unclear. What did you do first?"
- "Describe a technical decision you disagreed with. What happened?"
- "What is the last piece of feedback on your code that you did not agree with?"
Listen for specifics: what they did, what they said, and what changed. Vague answers are an answer too.
A separate communication score helps here, because it gives you a baseline before the call. Our piece on how to read a developer's score before the interview shows how to use it.
What to do this week
You do not need a new process to start. Change these four things:
- Write down the role's three real tasks. What will this person actually do in their first month? Our guide to writing a role brief that gets a shortlist fast helps.
- Turn one task into a test. Keep it short and close to the real job.
- Require supervision. If you cannot confirm who did the work, do not trust the score.
- Move the interview to what the test cannot show. Spend the call on disagreement, unclear briefs and how they work with others.
After the hire, keep checking. Our article on how to test a new developer in the first two weeks covers that.
How Talent Navigator does this for you
Vetting is the product here. Every visible profile has cleared four things: a role-specific technical test taken under camera supervision, a separate communication score, a video introduction, and verified education and work history.
There is no recruiter in the middle. You search, shortlist and interview yourself, with the scores in front of you. Your interview time then goes on judgment and fit, not on checking whether the person can code. If you want to see how that works without an agency, read how to hire developers without a recruiter in between.
Frequently asked questions
Is a technical test better than an interview?
Neither is better on its own. A test shows how someone writes code, and an interview shows how they think, communicate and handle people. Use the test first, then spend the interview on what the test cannot show.
Should every developer take a test?
For most roles, yes, as long as the test matches the job. A short, relevant task treats candidates fairly because everyone gets the same one. Keep it respectful of their time.
What is the one thing a technical test can't show?
How the person handles a disagreement or a vague brief. Those come out in conversation, so ask about real past examples in the interview.
If you want profiles that already come with a supervised score, a communication score, a video introduction and verified history, browse vetted talent and see the scores for yourself.