15.09.20233 min
Adam Kukołowicz

Adam KukołowiczCo-founderBulldogjob

Why Kotlin breaks so late into TIOBE's Top 20? Because TIOBE index is flawed.

Kotlin's late arrival into TIOBE's Top 20 prompted us to take a closer look at the TIOBE index itself. Spoiler: it has a major flaw.

Why Kotlin breaks so late into TIOBE's Top 20? Because TIOBE index is flawed.

For the first time, Kotlin has made it to the top 20 of the TIOBE index. One can boldly ask - how so? After all, Kotlin is one of the most popular programming languages. The problem is not Kotlin or its users, the problem is the TIOBE index itself.

Kotlin's Place in IT

Kotlin has been gaining popularity for several decent years now. Its biggest leap happened when Google chose it as the official language for native Android apps. It also gains more and more recognition on the backend, simplifying the development process, thanks to a more expressive syntax.

Regarding the data in our IT Community Survey 2023, concerning knowledge of programming languages, Kotlin took 10th place - 7.4% of commercially working developers declared its knowledge. In the StackOverflow Survey 2023, 9.7% of developers declared knowledge of Kotlin. This gave it the 15th position.

Kotlin's Place in TIOBE

In the TIOBE ranking, Kotlin has made it to the top 20 for the first time. Okay, maybe it would be nothing unusual if it weren't for the languages that rank higher than Kotlin.

And the elite group includes - Visual Basic (position 7), Fortran (place 11), Matlab, Scratch, Delphi/Object Pascal (places 13-15).

Something’s fishy here. None of these languages even appear near Kotlin, neither in our survey focused on the situation in Poland nor in the most global StackOverflow survey.

It's strange because TIOBE itself claims:

The TIOBE Programming Community Index is an indicator of the popularity of programming languages. The index is updated once a month. The ratings are based on the number of qualified engineers worldwide, courses, and third-party vendors.

If so, it's weird that JavaScript is only in 6th place (right before Visual Basic), C and C++ occupy 2nd and 3rd place, and Java and C# are behind them.

The Problem with TIOBE

What appears in the index results directly from its methodology, which is presented on the TIOBE website:

Basically the calculation comes down to counting hits for the search query

+"<language> programming"

It seems to us that the number of results for such a query may not translate into the actual popularity of programming languages. This index definition will reward languages taught at schools or universities - hence the presence of Matlab or Scratch in the index, or even Python's first place in the index. Languages that do not have a very developed ecosystem will also be promoted. E.g. React results won't be counted as JavaScript-related. Besides, who the heck writes "JavaScript programming" anyway?

Now you know why we are not fans of the TIOBE index. And let's be clear - it's not about hating the TIOBE company - although when they write that their "ratings are based on the number of qualified engineers worldwide", it doesn't look the best.

The point is more that not everything that glitters is gold and sometimes it's worth checking where the results of this or another index come from especially since the results of various popularity indexes are widely discussed in many online publications.