• As part of the ClickHouse Core teams, you will contribute to, analyze, and optimize the performance of the core ClickHouse database. The team works on many different topics such as query optimization, distributed query optimization, relational operators (e.g. aggregation and joins), caching, and low-level optimizations like SIMD instructions. • You will ensure that the database performance does not deteriorate over time by extending existing and adding new performance tests, based on real-world or synthetic datasets. • You will serve as a resource for the Support Engineering team, helping to debug the most advanced performance issues encountered by our customers. This includes an on call rotation as well as participation in our external community support channels. • As the core ClickHouse database continues to move at a fast pace, you will closely collaborate with our other teams to assess the impact of new features on performance and reliability. • You will work with our open-source community. This will include resolving issues, reviewing and finishing PRs, answering questions from mail, chats, google groups, external Slack channels, etc.