Darrell has recently spent a lot of time in and around the extensible GraphQL validation system. What started as a simple rule to fill a gap in the default rule set, soon turned into a plethora of custom rules to validate every detail of schema business logic in the Neo4j GraphQL Library. He will walk through some basic rules, and demonstrate how the system has been used to implement more complex logic.

Ditto.live is one of the leading local-first software platforms. In this talk, Senior Distributed Systems Engineer and CRDT wrangler Russell Brown shows how Ditto replicates data by syncing differences in state.

Zero is a new library for Local-first development that automatically replicates a subset of your Postgres database in your browser.

Zero is an excellent fit for Svelte. If I had to say in one line why Svelte feels magical, it's that there is no trade-off between developer experience and user experience - it makes it easier to write better software. Using Svelte, some problems just disappear entirely, and we are given tools to make other problems much easier to tackle. Zero extends this magic. Delays waiting for page loaders and form submissions disappear, and pages update instantly in response to changes made by other users. Zero is currently in Alpha but already in a state where it's quicker to build a feature with Zero than with regular Svelte loaders and actions.

In this talk I'll go over how to set up Zero, what it can do for you, how it compares to alternatives, why it's such a good fit for Svelte, and why I think that this is the first usable product in a new category that will change the way we write a lot of software.

CRDTs make perfect sense for disconnected applications, but they're only part of the puzzle. This talk is a short look at real world challenges faced when putting CRDT backed applications into real world customer deployments.