Multi-site retail
OmniPOS
Enterprise offline-first point of sale
An offline-first, multi-tenant point-of-sale platform with conflict-safe ledger synchronisation, engineered so that a dropped connection never costs a transaction.
This example comes from the technical delivery experience behind AussieSync. It does not necessarily represent a project contracted directly through AussieSync.
Have a process like this one? Tell us about it.
01 Problem
Retail environments suffer from network instability, causing data conflicts and lost transactions.
- Registers on congested or rural links dropped mid-sale, leaving orders half-written.
- Two tills editing the same stock line produced silent divergence once both reconnected.
- Retries after a timeout double-charged customers, because writes were not idempotent.
- Head office could not trust end-of-day totals without a manual reconciliation pass.
02 The solution
Engineered an offline-first multi-tenant system with conflict-safe ledger synchronisation.
- Every register holds a durable local ledger and stays fully operable with no network.
- Sales are appended as immutable, causally-ordered entries rather than mutable rows.
- A versioned change-log drives sync, with domain-specific merge rules on reconnect.
- Client-generated idempotency keys make any retry, network or human, a no-op.
- Tenant isolation is enforced at the data layer with row-level security.
03 Technical approach
Every choice earns its place.
- AngularRegister UI that stays responsive while entirely offline.
- GoSync and settlement services, for predictable latency under load.
- PostgreSQLSystem of record; row-level security enforces tenancy.
- RedisQueues and leases that keep replay ordered and exactly-once.
- SQLiteThe durable on-device ledger each register writes to first.
04 Outcome
Achieved zero data loss during connectivity drops and ensured financially correct, idempotent transactions.
- Zerotransactions lost to connectivity drops
- Never stopsselling, so the business trades through an outage
- One codebaseserving many tenants