Mock interview: the offline-first POS platform at Tillsy

A recorded staff-level final loop with Dr. Meera Iyer at Tillsy: billing that never needs the cloud, the reconnect storm, an idempotent versioned sync protocol, conflict rules without device clocks, regions and cells, a dedicated-cell deal, no-bill-lost guarantees, GDPR erasure against tax retention, a Diwali incident and the biggest risk in the design.