Berlin has a very vibrant tech startup scene – and as everywhere they appreciate jacks of all trades. Wages are significantly lower than in Silicon Valley, but so are the cost of living.
I'd expect you'd earn something along the lines of 30-40k per year after tax, very good federal healthcare included. As teacher it could also be slightly more, but I'm not sure how easy it'd be to get a job in that field as non German speaker. English is fine though in tech and everyday live.
A nice 2-3 room flat in the areas where you'd want to live is about 800 to 1200 euros per month. Or generally speaking, one square meter costs roughly 10 to 13 euros monthly.
Party is good Or if you've outgrown that, kindergarden and education in general are free.
Depending on what you're used to, winter in Berlin sucks though.