Top programming languages: JavaScript and Java in high demand

Data from 304,645 coding tests by assessment platform DevSkiller identified the languages and tech stacks developers were most likely to be tested on.

Focused developer coding on computer monitors working late in office

JavaScript and Java continue to top the list of most in-demand programming languages.

Image: Getty Images/iStockphoto

Java and JavaScript are predicted to be the most in-demand IT skills in 2021. Results from DevSkiller's IT skills report 2021, which looks at demand and hiring trends in the tech sector, reveal that Java and JavaScript were the programming languages that developers were most likely to be tested on its platform.

The two popular languages were seen in 43% of test invites, followed by SQL (41%), .NET/ C# (15%), and CSS/ HTML (14%).

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The results don't add up to 100% because a DevSkiller test can include multiple programming languages, for example Java+SQL. In the same way, the percentage in the chart refers to when the technology is tested in any test, DevSkiller explained.

Java and JavaScript both being in the top spots suggests that companies see equal importance in both front-end and back-end development.

Even so, JavaScript remained the go-to programming language in DevSkiller's report for the second year running.

In 2020, three-quarters of companies were looking for JavaScript developers. SQL came in second place with 63%, while Java had dropped slightly to 51%. 

HTML/ CSS and .NET/ C# both saw small improvements from last year at 48% and 41%, respectively.

The 2020 Stack Overflow Developer Survey drew a similar conclusion, with JavaScript holding onto the top spot and Java trailing just a couple of positions behind.

A survey from programmer-training company CodinGame earlier in January found JavaScript, Java and Python to be the most sought-after programming languages among hiring managers.

DevSkiller noted that it was seeing a growing shift towards TypeScript – a subset of JavaScript created by Microsoft – as a replacement to JavaScript.

"The reason it was not specified in this report was because we classify most TypeScript coding test invitations on our platform as JavaScript," read the report.

"Next year we will be placing greater emphasis on distinguishing these two IT skills."

Tech stacks

Developers are often tested on their knowledge of tech stacks – the combination of programming languages, libraries, frameworks and other tools used by an organization to build software applications.

React, MySQL, Spring, ASP.NET, Data Analysis, HTML, Laravel, and Bash were found to be the most popular technologies in their respective tech stacks within DevSkiller's report.

React, the JavaScript library used in web development to build user interfaces, was the most popular technology in the JavaScript tech stack, seen in 35% of tests. It also topped the Hacker News hiring trends for the 31st consecutive month.

ES6 came in second place, with just under a quarter of JavaScript developers tested using it. Rounding out the top five were Angular2+, Nodejs, and Redux, which only just managed to edge out Vue.js, which came in sixth place.

The Spring framework was the most popular tech stack resource, used in 36% of Java tests, while Spring Boot, an enhanced extension of the Spring framework, came in second place. This was followed by Hibernate (18.03%), Gradle (16.08%), and Maven (8.77%).

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For .NET coding, ASP.NET was seen in almost half of all .NET/C# tech stacks. MySQL led the SQL tech stack with 53% of tests, while Python 3.x was used in 71.07% of Python tests

Laravel was the most popular resource in the PHP tech stack, with 26.65% of tests.

Which devs score highest?

The data used for DevSkiller's study came from a 365-day snapshot of users on the assessment platform between December 2019 and December 2020.

The insights are based on aggregated demographic data from 304,645 coding tests taken through the DevSkiller platform by candidates in 156 countries.

Amongst the other insights, DevSkiller found that Australian developers often scored the highest on coding tests, scoring an average of 93.56%. In second place were US candidates, scoring an average of 90.01% on tests, followed by Sweden (90.35%), Portugal (89%), and Poland (87.5%) and Ukraine (85.03%), which only just managed to nudge the UK into 7th place, with candidates scoring an average of 85% on tests.

The platform saw a higher uptake of coding tests in 2020, which it said reflected the volatile job market and the fact that some people had been forced into unemployment as a result of the COVID-19 pandemic. As a result, more people have been learning to code as a means of skilling up and opening themselves to new job opportunities.

While this could lead candidates down new career paths, it also creates more competition by giving employers a wider pool of candidates to choose from.

"The impact of the COVID-19 outbreak was felt heavily last year and resulted in many developers losing their jobs," read the report.

"Consequently, companies have had a wider candidate pool to choose from, which has allowed them to be more selective about who they consider. Although the pandemic has heavily affected hiring patterns this past year, we expect selectivity to continue for companies that test candidates from particular countries."

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