About Simmis
A simulation platform for people who need to think through complex systems before acting on them.
The idea
Most tools help you record what happened. Simmis helps you reason about what could happen. It combines structured knowledge management with simulation — you model your processes, branch the world, run scenarios, and compare outcomes before committing to a decision.
The system itself learns from the outcomes you observe. As you accumulate experience, predictions improve. The goal is a tool that thinks alongside you — not by replacing your judgment, but by making the consequences of your choices visible before you make them.
The stack
Simmis is built on the Datahike ecosystem: immutable databases with git-like branching, columnar analytics via Stratum, and a unified versioning protocol via Yggdrasil. Every state is a value. Every branch is free. Every simulation is reproducible.
Who's building this
Simmis is built by Christian Weilbach, who previously built Datahike (open-source immutable database) and researches structured probabilistic inference. The common thread: systems that accumulate knowledge, reason with their own history, and remain inspectable.
Get in touch if you're interested in using Simmis for your work, or if the vision resonates and you'd like to contribute.