Two questions. 1) What is Pilosa written in? 2) How would I implement Pilosa in my own stack?
2. It's going to depend on your use case, but generally you will be streaming writes into your current data store as well as Pilosa. Then read queries will be serviced by Pilosa, or by a combination of Pilosa and your system of record depending on the data you need.
We're more than happy to help explore how you might use Pilosa - get in touch with us on github, or through https://www.pilosa.com/about/#contact