Our latest projects are using Redis, PostgreSQL, mongodb, Elastic Search and MS SQL Database.
We started in 1998 with Microsoft SQL Server and are still using it daily for some customers.
Few years also we started using PostgreSQL, this a very powerful SQL server, it never failed us.
For embedded (on raspberry pi) or mobile application we use SQL Lite.
In the nosql categories we have experience with mongodb, elastic search and Redis.
We mainly use Redis for cache purpose.
We have used mongodb in several projects since 2012. Mongodb offers us great performance and perfect match to Web application business.
For Elastic Search we use it to handle our applications logs (with kibana). So our developers get a centralized log database they can query from a single place.
We also use Elastic Search for multi lingual text search, it's very powerful.