From MemSQL to HorizonDB, an engineer's journey with Adam Prout

What does it take to make Postgres and Azure fit together cleanly, like puzzle pieces? In Episode 39 of Talking Postgres, Adam Prout—distinguished engineer at Microsoft and a founding architect of Azure HorizonDB—joins Claire to trace his engineering journey from MemSQL to Postgres. We dig into shared-storage architecture and how HorizonDB pushes more work into the storage layer; why the team chose Rust; and what “good systems programming” looks like when being paranoid is a feature, not a bug. Along the way: startup vs big company tradeoffs, and how working on databases exposes you to so many interesting parts of computer science.  

Previously on Talking Postgres:

• Talking Postgres Ep29: How I got started leading database teams with Shireesh Thota

Links mentioned in this episode:

• Blog post: Announcing Azure HorizonDB, by Charles Feddersen & Affan Dar
• CMUDB talk: HorizonDB: Co-Designing Postgres and Azure for Cloud-Native OLTP, by Adam Prout
• Research paper: Socrates: The New SQL Server in the Cloud
• Product page: Azure HorizonDB
• Video of POSETTE 2025 talk: Scaling Postgres to the next level at OpenAI
• Blog post: Scaling PostgreSQL to power 800 million ChatGPT users, by Bohan Zhang
• Blog post: Supporting ChatGPT on PostgreSQL in Azure, by Affan Dar, Adam Prout, & Panagiotis Antonopoulos 
• Docs: Azure Database for PostgreSQL
• GitHub repo: pgrx
• Discord: PostgreSQL Hacking server
• Conference: PGConf.dev 2026
• Conference Schedule: PGConf.dev 2026 Schedule