This course describes Extract, Transform, and Load (ETL) processes to take your database from raw observational data to the OMOP Common Data Model. Steps 1 and 2 will focus on the tools available for designing ETL logic in a way to communicate to a developer how source data should be handled during conversion to the OMOP Common Data Model. This includes discussion of practical methods for mapping source vocabulary values to Standard OMOP Concepts and a demonstration of how to handle situations where pre-specified mappings do not exist. Steps 3 and 4 will go over some examples and guidelines when it comes to implementing and testing the ETL logic.