> I want to underline that in most countries in Europe, the language of programming and tech environments is mostly English (documentation, internal communication, white-board meetings). So just English is enough in most cases.

That is not my experience of working in Poland. As a native, I've worked in multiple projects and Polish was the communication language in all of them. I am sure there are jobs available where everyday communication is in English, but my guess would be that they are in minority.