Hi, I'm Tobi

Technical Product Owner by day, OSS software engineer by night. I like building products in the cloud on AWS or Cloudflare, DuckDB, SQL, modern data stacks, GIS tools and some sprinkles of web development.

I'm leveraging AI tools like Codex, Claude Code and custom agent harnesses to build useful things with a product mindset, fast.

Read Blog Posts See Projects About Me

Recent Blog Posts

View All Posts

Merges for DuckDB branches and snapshots

differential 1.1 brings three-way merges to DuckDB: merge branches and snapshots, fast-forward, resolve typed conflicts with a table, merge schemas, use S3.

October 27, 2026

25 min read

duckdbsqldata-engineering

Using a local Codex App Server from ChatGPT and the terminal

Connect to a local Codex App Server from the terminal, over SSH, or through the ChatGPT desktop and mobile apps while keeping your projects on your machine.

October 27, 2026

5 min read

codexchatgptai

Diffing DuckDB branches and snapshots with plain SQL

Diff DuckDB branches and snapshots with plain SQL: EXCEPT, a keyed FULL JOIN, changed columns and a reusable cell-level diff macro for differential.

October 23, 2026

9 min read

duckdbsqldata-engineering

Versioned DuckDB databases, locally or replicated through S3, for people and agents

differential extension for DuckDB 2.0: snapshots, branches and time travel locally, plus leader/follower replicas, failover and shared writers via S3.

October 21, 2026

12 min read

duckdbdata-engineeringsql

Teaching coding agents the differential DuckDB extension with an Agent Skill

duckdb-differential now ships an Agent Skill, so Claude Code, Codex, Cursor and other agents can version, branch and replicate DuckDB databases correctly.

October 21, 2026

8 min read

duckdbaiskill