Why Fetch When You Can Sync? Building Local-First Apps on a Sync Engine Architecture

Abstract

Front-end has long been about reactivity frameworks and client-side state management. However, the alpha in these is receding. The next frontier, with much bigger gains across UX, DX and AX lies in extending reactive state management to the server with local-first apps built on a sync engine architecture.

Local-first apps built on sync are instant to use, always work and naturally support realtime collaboration. Eliminating stale data, loading spinners and manual data wiring. It's an ideal architecture for building AI apps and agentic systems where you have multiple users and agents collaborating on the same state. And the switch from imperative data fetching to declarative sync also makes LLM generated code more maintainable and suitable for production apps.

This talk introduces the principles of local-first and sync engine architecture and shows you how you can adopt these patterns today using TanStack DB, a new reactive client store for building super fast apps on sync that's now built directly into TanStack.

Interview:

What is your session about, and why is it important for senior software developers?

It's about building apps and agentic systems on a local-first, sync-engine architecture that makes apps fast, modern and naturally collaborative.

Why is it critical for software leaders to focus on this topic right now, as we head into 2026?

Software UX, DX, and AX are all being redefined and reinvented right now. Sync is key to building AI apps and agentic systems.

What are the common challenges developers and architects face in this area?

Slow apps. Loading spinners. Stale data. Migration challenges. Operational complexity. Scaling. Silos.

What's one thing you hope attendees will implement immediately after your talk?

Switch one route/fetch/component of one of their apps to use TanStack DB.

Speaker

James Arthur

Co-founder and CEO @ElectricSQL, Previously Co-Founder and CTO @Hazy and @Opendesk

James is Co-Founder and CEO of ElectricSQL. Prior to founding Electric, he co-founded the Post Urban venture builder and was co-founder and CTO of synthetic data company Hazy. Before that, James was co-founder and CTO of digital manufacturing company Opendesk and developed software for companies including Apple and IDEO. James’s projects have won a TED Prize and the $1M Microsoft Prize for the best startup in Europe.

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Date

Tuesday Nov 18 / 10:35AM PST ( 50 minutes )

Location

Pacific DEKJ

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