Could you recommend me a presentation / video / blog posts about organising workflow in really big IT companies where they have e.g. over 20 Developers taking care of a single app?

During my time at Ford, I was quite impressed by how Pivotal guided them - taking them pretty much from zero to hero. I'd recommend looking for posts by them in any field that you might find relevant 🙂

🙂 20 devs isn't that much

there is another Slack community that can also guide you https://www.softwarecrafters.org/

Hmm. Not sure about that. If I had 300 devs, I'd still care if I lost 20 devs and still be happy if I got 20 more. 20 engineers can do a LOT

In my open source team ( ~14 devs ) we use Trello as kanban board and Slack for communication but this is small project and we know each other well.

I’ve been working only for startups for last 7 years, I wanna try something new so I’m applying for jobs in big companies. Tbh, 20 Android devs working on a single app is blowing my mind 🙂

2 pizza teams here at Amazon