I worked at Yugabyte, a company focused on building high-performance distributed SQL databases. During my internship, I contributed to several projects that improved the performance of the YSQL query layer and the DocDB storage engine. One project involved adding bulk inserts to the COPY command, which resulted in a 30x speedup. Another project added a non-transactional fast path for single-row UPDATE/DELETE statements, which sped up affected queries by 2.5x. The final project focused on aggregate pushdowns, allowing queries to be pushed down to the distributed storage layer, reducing unnecessary overhead and RPCs. These changes improved the performance of the database while preserving its transactional guarantees and features.