Live & Local Schema Change Challenge Problems

Jonathan Edwards, Tomas Petricek, Tijs van der Storm

Presented at LIVE 2023

Schema change is an unsolved problem in both live programming and local-first software. We include in schema change any change to the expected shape of data, whether that is expressed explicitly in a database schema or type system, or whether those expectations are implicit in the behaviour of the code. Schema changes during live programming can create a mismatch between the code and data in the running environment. Correspondingly, Schema changes in local-first programming can create mismatches between data in different replicas, and between data in a replica and the code co-located with it. In all of these situations the problem of schema change is to migrate or translate existing data in coordination with changes to the code.

This paper contributes a set of concrete scenarios involving schema change that are offered as challenge problems to the live programming and local-first communities. We hope that these problems will spur progress by providing concrete objectives and a basis for comparing alternative solutions.

Paper and more information


If you want to cite the paper, you can use the following BibTeX information.

  title={Live \& Local Schema Change: Challenge Problems},
  author={Edwards, Jonathan and Petricek, Tomas and van der Storm, Tijs},
  journal={arXiv preprint arXiv:2309.11406},

If you have any comments, suggestions or related ideas, I'll be happy to hear from you! Send me an email at or get in touch via Twitter at @tomaspetricek.

Published: Monday, 23 October 2023, 12:00 AM
Author: Tomas Petricek
Typos: Send me a pull request!