Payments Reliability Engineer: Reconciliation & Webhooks

Ordernised; Greater London; Hybrid; GBP 80,000 - 110,000; Full time

Job summary

Ordernised in London is seeking a backend engineer to own payment, refund and reconciliation workflows where customer experience and financial correctness meet. You will design robust money-related systems and ensure traceability across services.

You will collaborate with product, operations and other engineers to implement reliable event processing, test for repeated events and support investigation through strong audit trails.

Qualifications

• Strong backend engineering experience in payment or financially sensitive workflows.
• Understanding of idempotency, retries, reconciliation and reliable event processing.
• Confident SQL and data modelling skills, including transactions and traceability.
• Ability to handle monetary calculations with consistent methods.
• Experience explaining complex failure modes to technical and non-technical colleagues.

Responsibilities

• Build and maintain payment-provider integrations for checkout, refunds and connected merchant accounts.
• Design idempotent webhook processing and explicit payment-state transitions.
• Develop reconciliation workflows that identify mismatches without altering financial records.
• Model monetary values, fees and rounding across interfaces and storage.
• Create tests for repeated events, partial failures, refunds and delayed confirmations.
• Improve audit trails and internal tools used to investigate payment issues.
• Coordinate payment releases and provider changes with engineering and operations teams.

Skills

Backend engineering

Payments systems

Idempotency

Retries

Reconciliation

SQL

Data modelling

Event processing

Auditability

Technical communication

Job description

Ordernised in London is seeking a backend engineer to own payment, refund and reconciliation workflows where customer experience and financial correctness meet. You will design robust money-related systems and ensure traceability across services.

You will collaborate with product, operations and other engineers to implement reliable event processing, test for repeated events and support investigation through strong audit trails.