I don't know what Google pays for a Senior engineer, but from what I know about Amazon it's about 70-100k. Other companies that pay on this level:

- Zalando

- HERE Technologies

- N26

- Delivery Hero

- Soundcloud

- VW/Mercedes/Porsche backend startups (Proshare, Coup, Porsche Digital Lab)

And many smaller ones. From my circle, most Senior engineers earn in the 70-100k range total compensation. Since Berlin is still quite affordable, that allows a good standard of living.