Creston Jamison is a US database engineer and the host of the long-running Scaling Postgres YouTube channel and weekly newsletter — one of the more authoritative independent sources on PostgreSQL performance and operations.
His CourseFlix listing carries Ludicrous Speed Postgres — a focused treatment of PostgreSQL performance engineering: indexing strategy, query optimisation, the EXPLAIN plan reading craft, partitioning, and the operational tuning that separates fast Postgres from generic Postgres.
Material is paid and aimed at engineers responsible for PostgreSQL performance on production systems. For broader content, see CourseFlix's Databases and SQL category pages.