All you need is PostgreSQL
Summary
The article argues for using vanilla PostgreSQL 18 with standard extensions to build a complete OLTP/OLAP financial ledger system, focusing on immutability, state machines, and auditing. It covers foundations (schemas, domains, account types), transfers life cycle, system-time history via temporal tables, constraint triggers, balance ledger for analytics, decoupling via an updatable view, and serialization-safe isolation with PostgreSQL SSI. It also includes extensive code examples and benchmarking results to support the approach.