Which C++ version is the most commonly used in the tech industry today?

Honestly, it probably depends on when the bulk of C++ projects were launched, as newer projects usually adopt the latest version. I remember back in the day, Watcom C++ was quite popular, especially for games like Doom. But these days, I’d say stick to at least C++17 for new projects because it has some great features. If you can, get familiar with C++20 too, as it has some really nice enhancements!

From my experience, there's quite a bit of variation depending on the team and the project. Generally, most teams start incorporating features from newer versions of C++ once they’ve been proven stable across the compilers they use, like gcc, clang, and MSVC. A typical project today might support C++20 but not C++23 yet, as many companies don't want to adopt the very latest features unless necessary. Often, old code isn't rewritten even if newer features are available, especially if it’s stable and functional. So it’s a mix – you might see C++11 in older codebases, but C++20 is becoming the standard for new projects.