End-to-end payment flows
Map how requests, callbacks, retries and state transitions cross internal and external boundaries.
Industry / Payments
Protect every handoff in the payment lifecycle.
Security engineering for gateways, processors, payment APIs, ledgers, reconciliation systems and settlement dependencies.
ORIGINMerchant
ROUTEGateway
RAILPayment core
FINALSettlement
PROTECTION OBJECTIVE
Keep money movement authorised, traceable and resilient from initiation through final settlement.
Payment APIs Rail integrations Ledger integrity Reconciliation
WHERE WE WORK
Engineer security around the movement of value.
Payment risk lives between systems. We examine each handoff together: identity, routing, authorisation, state changes, ledger writes, reconciliation and settlement.
Discuss your environmentAuthorisation and abuse
Test broken access control, replay, idempotency, manipulation and business-logic abuse paths.
Ledger and reconciliation
Review integrity controls around balances, journals, settlement files and exception handling.
Rail resilience
Assess third-party dependencies, degraded modes, failover and operational recovery paths.
ENGAGEMENT MODEL
From system context to verified improvement.
Focused work that leaves engineering teams with decisions, evidence and a practical route forward.
Trace
Follow a payment from request through ledger and settlement.
Harden
Design controls for the failure and abuse paths that matter most.
Prove
Exercise the controls and retest fixes against realistic payment scenarios.
ENGINEERING OUTPUT
Evidence your team can use.
Clear artefacts designed for engineers, security leaders and decision-makers.
- Payment-flow and dependency model
- Business-logic abuse case library
- Ledger and reconciliation control review
- Actionable validation report with retest evidence
Let’s identify the security work that matters first.
Share the system, its current stage and the outcome you need.