Furthermore, we worked with document-oriented NoSQL databases:
column-oriented Cassandra database
Hadoop based NoSQL database called HBase.
We built a lot of ETL pipelines in order to move the data between different sources and transform them.
We used the Pentaho ETL engine for these purposes as well as built our own pipelines using Java and Python programming languages.
On some of the projects we have built OLAP cubes for building the system that provided capabilities of dynamic reports generations and we used MS SQL Server, SSIS, Microsoft SQL Server Analytics Services.
Working with data we cover the wide range of technologies here.
First, throughout our company lifetime we had a practice with almost all modern DBMS: