Developing a distributed SQL database poses several technical challenges, including architecture, SQL protocol, distributed transactions, clock synchronization, and query layer design. The authors of YugabyteDB, a cloud-native, open-source database, faced these challenges while building their database, which draws inspiration from Google Spanner's architecture but retains a PostgreSQL-compatible query layer for broader compatibility. After exploring various options, including Amazon Aurora and MySQL, the team decided on a hybrid approach combining the scalability of Spanner with the functionality of PostgreSQL. They also addressed issues related to distributed transactions, clock synchronization using Hybrid Logical Clocks, and rewritten or reused PostgreSQL's query layer. Ultimately, YugabyteDB offers a unique set of architectural decisions that balance practicality with power, making it an attractive option for applications requiring horizontal write scalability, low read latency, and compatibility with popular SQL databases.