If you are a software engineer or someone learning or interested in software development you might want to create an account on an instance with other software developers so that your local timeline is full of relevant content.

ForFedidevs I have indexed some of the most popular Mastodon instances and used regexes to try and find accounts that belong to software developers.

I indexed only a small percentage (0.225% by my count 😅) of all Mastodon instances, but this set of instances includes the majority of English-speaking users on Mastodon (see the full list of instances in theFAQ page).

The results

Count   Instance2963    mastodon.social1083    hachyderm.io513     mastodon.online447     ruby.social441     mstdn.social377     fosstodon.org361     infosec.exchange343     mas.to335     phpc.social258     techhub.social

No surprise thatmastodon.social is on top here. It's one of the largest Mastodon instances with more than 1 million users. That's 1/6 of Mastodon's total users according tomastodon.help. Even thoughmastodon.social has the most developers of any instance, it also has the most users so the percentage of developers is not that high and your local timeline will most likely not have content relevant to you.

hachyderm.io is an LGBTQIA+ and BLM safe space focused on tech industry professionals worldwide.

mastodon.online is another very popular general purpose instance.

phpc.social andruby.social are instances for people interested in Ruby and PHP programming languages.

fosstodon.org a community for anyone interested in technology; particularly free and open source software. The custom emojis on this instance are amazing 👌

infosec.exchange focuses on info/cyber security. If that's what you are interested in this is probably the best instance for you!

techhub.social is primarily for passionate technologists, but according to the instance description everyone is welcome.

Breakdown by popular languages

Python developers

Count   Instance562 mastodon.social294 hachyderm.io124 fosstodon.org108 mastodon.online100 mas.to99  infosec.exchange97  mstdn.social73  techhub.social48  mastodon.gamedev.place35  mastodon.worldCount

The Python community has recently started to migrate away from Twitter and a lot of prominent Python community members no longer post on Twitter.

Besides the two largest instances most Python developers seem to hang out onfosstodon.org. This is where some of the largest Python-related accounts live, including theofficial account for the Python Software Foundation,Michael Kennedy,Brett Cannon, and others.

JavaScript developers

Count   Instance448 mastodon.social299 hachyderm.io95  techhub.social89  mas.to84  phpc.social82  mastodon.online74  fosstodon.org73  mstdn.social59  ruby.social38  infosec.exchange

The top two largest instances for JavaScript developers are the same as the Python ones, but fosstodon.org isn't as popular with JavaScript developers as it is with Python developers.

Rust developers

Count   Instance458 hachyderm.io226 mastodon.social57  mastodon.gamedev.place52  mas.to49  infosec.exchange42  mastodon.online38  fosstodon.org30  mstdn.social28  techhub.social17  chaos.social

Rust developers seem to preferhachyderm.io overmastodon.social and it seems to be the only programming language with these instances switched.

Ruby developers

Count   Instance478 ruby.social151 mastodon.social118 hachyderm.io25  mastodon.online24  mas.to18  mstdn.social17  infosec.exchange15  techhub.social13  mastodon.world12  fosstodon.org

No surprise that Ruby developers prefer the ruby Mastodon instance -ruby.social.

PHP developers

Count   Instance370 phpc.social200 mastodon.social38  fosstodon.org38  mas.to36  hachyderm.io31  mastodon.online24  mstdn.social15  infosec.exchange13  mastodon.gamedev.place12  techhub.social

Similar to Ruby developers PHP developers also have their instancephpc.social. Unlike the Ruby community, it seems like the PHP community is more spread out and the official PHP instance takes up a smaller percentage of users than the ruby.social instance in the Ruby community.

Other popular languages

Fedidevs also allows filtering byJava,C#,Golang, and others. But the amount of accounts isn't as high as the ones listed in this article so I've omitted it for brevity. Let me know if you would still want to see the statistics for these in the comments below.