AgileEngine, LLC. is seeking a Senior Software Engineer to own offline-first data synchronization for a general QSR POS platform, designing multi-tier sync across device, restaurant edge, and cloud backend. You will implement conflict-resolution using CRDT-based frameworks including Automerge or Ditto, apply event sourcing, CQRS, and saga patterns across order and payment flows, and model the PostgreSQL cloud data layer against local and edge stores.