by Tom Winter

What we learned about 2019 developer hiring trends from analyzing 112,654 coding tests


Information is key when recruiting developers — whether you are the recruiter or the developer.

If you know the trends in the industry, what skills are being sought after, and the places developers are being recruited from, it becomes much easier to match the right developer with the right company.

We have been on a mission to improve the level of knowledge in tech recruitment. Developer hiring data is a key part of that, but we ran into a problem.

There’s a lot of information out there about developer hiring trends. But how much of it is actually useful?

Surveys, after all, require self-reporting. But the importance of hiring that developer or landing that job demands a data source that is more concrete. We certainly thought so, which lead us to look at the data which we already had.

At Devskiller, we have been sitting on a growing pile of coding tests (112,654 for last year alone). That is special for a big reason. Actions speak louder than words. Our coding test data reflects the skills companies are actively recruiting for, and the locations they are doing it in.

These are not the impressions of technological diviners — they are the stated intention of technical recruiters from all over the world.

Armed with this dataset, we went digging and discovered some tremendous insights.

Developers from New Zealand score the highest (54.66%) on coding tests

If there’s one thing I’ve learned about developers, there’s a healthy sense of competition between them.

They’re always looking for ways to compare their skills to their peers. These competitions can take on an international character and reflect something about the way developers see their levels of educational attainment and technical proficiency.

We’ve tested candidates from over 120 countries, so wanted to see how developers from different countries stack up against each other.

Source: Devskiller Global Technical Hiring & Skills Report 2019

As it turns out, New Zealand came in top place with an average score of 54.66%, closely followed by the Netherlands.

So why is this?

Is it down to educational style, or do developers from certain countries simply get easier tests than developers in other countries? New Zealand has done a lot to attract the best foreign talent, so these new arrivals could affect the national score.

The question becomes then, are the developers in the countries that score the highest on coding tests also the ones being sought after internationally?

The US is the largest recruiter of overseas developers, but also represents the second largest pool of overseas candidates

Over 30% of the overseas candidates in the study were tested by US companies. This is despite the fact that only 40% of the developers tested by US companies were from overseas.

Volumes like this should probably come as no surprise given the size of the tech sector in the country. The US also has famously high wages for tech talent that can attract the top talent from all over the world.

Source: Devskiller Global Technical Hiring & Skills Report 2019

Probably more extreme is when you look at the countries that produce the most candidates. India comes in first, with over a quarter of all the candidates tested on the platform.

Interestingly, the US comes in second place. This puts the USA in a fascinating position as being both one of the largest recruiter countries and candidate countries.

Source: Devskiller Global Technical Hiring & Skills Report 2019

What the US position shows is that there is a strong trend towards internationalizing the developer candidate labor pool. Perhaps this leads to greater efficiency, as companies are able to attract developers with the right skills no matter where they happen to be from.

At the same time, US developers are equally happy to work for overseas companies where their skills are in demand.

To find out what those skills are, we had a look at the technologies that companies are seeking all around the world.

70% of companies are looking for JavaScript developers

There tends to be a lot of talk about what the next big technology is going to be. With all the chatter about whether Kotlin is on the rise, or if Golang is going to dominate, it is easy to forget that these technologies are still less well-established.

In most enterprises, established technologies like JavaScript are still very much in demand. In fact, we found that 70% of companies are looking for JavaScript developers.

Source: Devskiller Global Technical Hiring & Skills Report 2019

Compare that with Java, the language which was tested the most overall in the study.

Source: Devskiller Global Technical Hiring & Skills Report 2019 (edited)

The data shows that JavaScript is useful both for smaller operations and large enterprises. Java, on the other hand, is more useful for large teams at a smaller number of companies.

Where you tend to see variation is not between tech stacks, but within them.

So while 70% of companies are looking for JavaScript developers, the particular framework or library, such as React, Vue, Angular, or Node.js is where the innovation is happening. In fact, it is these in-stack skills where developers are being tested.

Expect to be tested on knowledge within a tech stack rather than a language on its own

JavaScript is not the only tech stack where candidates are being tested on their knowledge of specific technologies and resources.

Instead, tests for all languages are getting much more granular with stack specific knowledge. If you are a Java developer, expect to be tested in Spring or Android, for instance.

JavaScript developers themselves could be tested in any number of frameworks including React, Angular, jQuery, Node.js, or Ember.

Database developers might be expected to know MySQL, PostgreSQL or HSQLDB.

PHP developers may need to know Laravel or Symphony.

And Python developers (depending on the requirements of the position) might just as easily be tested in Django as in Pandas or Numpy.

Source: Devskiller Global Technical Hiring & Skills Report 2019

The point is that it’s not enough to have broad language knowledge. There’s a value in being familiar with a particular tech stack and that’s increasingly what companies are looking for.

From this, we conclude that you should become familiar with relevant libraries and frameworks in addition to your general language skills.

Backend skills and database skills are often tested together

Of course, knowing a single tech stack might be okay for some positions. But increasingly, complementary tech stacks are being tested together. So the question becomes, what kinds of tech stacks are complimentary?

Overwhelmingly, we found that back end technologies are tested with SQL.

Of the top eight technologies tested together, over 26% of them were combinations of Java and SQL. Beyond that, .NET and SQL were tested in over 9%.

JavaScript, which with Node.js is now back end technology, is tested with SQL over 15% of the time. Finally, PHP is tested over 7% the time with SQL as well.

Source: Devskiller Global Technical Hiring & Skills Report 2019

When you use JavaScript on the front end, you see it combined with CSS over 18% of the time. Elsewhere, you see full stack tests being put together with .NET and JavaScript being combined over 8% of the time, PHP and JavaScript being combined over 7% of the time, and Java being combined with JavaScript over 6% of the time.

What we can take from this is that if you’re a backend developer, database skills are very important. Equally, if you are a full stack developer, the go-to language for frontend work is JavaScript, regardless of which backend stack you use.

73% of developers will take a coding test based on real work

Throughout this report, there’s been a lot of talk about coding tests. After all, these are what the data is based on. But they can be controversial in some circles.

Common criticisms include that they take too long, they’re irrelevant to the work being done, and that the developer can’t truly show off their skills. Certainly, these protests led to some developers declaring that they would simply pass over any job which requires a coding test.

Interestingly, we found in our study at full 73% of developers who were sent a Devskiller coding test as a part of the technical hiring process will take them. This just goes to show for people hiring developers that with the right test, you can get most of your candidates to take them. The result is that you get vital information about their skills.

Companies from Singapore are the most selective

Now if you take a coding test, developers from different countries tend to get different scores. Equally, not all employers are as selective with the candidates that they approve. Why is this?

Simple supply and demand comes to mind. You might have a lot of people going for a few positions in certain places. Equally, companies might set higher standards for what they want from a candidate.

It probably comes as no surprise then that Singapore is the most selective country for Technical Recruiters. Singapore is a well-developed country with really high levels of educational attainment. The OECD ranks them first in the world for all subjects.

On top of that, they have higher economic attainment than any of their neighbors and are therefore able to draw on candidates from around Southeast Asia.

What these insights mean for 2019

While this data was collected over the last year, it indicates some interesting trends for 2019.

  • Countries like New Zealand may be a fertile new source of high-quality developers
  • India is a huge source for developers but so is the US
  • Legacy technologies like JavaScript are still highly sought after
  • Become familiar with a tech stack rather than just a language
  • Developers should develop skills in complementary tech stacks to the ones they work in like a database stack for back-end developers
  • Coding tests based on real work will be taken by candidates
  • Companies from Singapore are highly selective

These are not the only insights you will find in the report. Check out the Devskiller Global Technical Hiring & Skills Report 2019 to get the complete picture of these insights and others.