MongoDB is a document-oriented NoSQL database system. It is based on JSON-like documents, on which a schema is not enforced, providing great flexibility for use cases that deal with significantly heterogeneous data.

In the context of the EOSC-Pillar project, I designed an ETL pipeline that extracted terms and their metadata from several types of RDF-based vocabularies (e.g. RDFS, SKOS, OWL and made them available on a MongoDB database. I then made some further analysis on the database, that was also used as data source for Elasticsearch. The goal of the task was building a search engine for concepts from ontologies. You can find more information in this presentation.