As a Senior Database Engineer, you will design, implement, and maintain robust database solutions using MySQL, MongoDB, and Cassandra. You will ensure high availability, performance, and security of database systems, while monitoring performance and applying necessary patches. You will also be responsible for developing and maintaining database documentation, collaborating with development teams for optimization, performing database tuning, and implementing backup and recovery strategies. Furthermore, you'll ensure data integrity, implement security measures, and provide technical support. The role requires staying updated with the latest database technologies and best practices.