Guru Rajan Ganesan is a MongoDB Developer-certified professional who works as a database administrator at Isentia, a media intelligence software company. He discovered MongoDB in 2012 while working on a natural language parser project and was impressed by its performance and scalability. Guru has worked with various databases including Microsoft Access, SQL, Sybase, Cassandra, Oracle, and Neo4j, but finds that MongoDB's flexibility to handle unique requirements makes it an attractive choice for his projects. He became interested in certification to demonstrate his expertise and gain market value, and is currently pursuing the DBA certification after completing the Developer certification. Guru advises aspiring MongoDB professionals to practice hands-on with the shell and analyze back-end activities to understand the architecture clearly. His greatest takeaway from his certification experience is increased confidence in handling MongoDB issues and earning the trust of his seniors.