Loyalty actions happened across disconnected channels, making discount handling and transaction traceability inconsistent.

The product had to support seller speed at checkout while preserving admin-level control over discount policy and shifts.

The system split responsibilities between customer-facing Telegram interactions and staff-facing POS workflows with shared transaction state.

Shift lifecycle, customer lookup, and discount validation were modeled as explicit state transitions to reduce ambiguity.

The loyalty process became operationally explicit: staff actions, discount decisions, and shift accountability are recorded in one system.

This reduced ad-hoc handling and improved handoff quality between store staff and management.

Balancing speed for checkout staff with policy enforcement requires careful UX prioritization and strict domain validation.

Monorepo coupling improves consistency but demands discipline in release coordination.