Payment Integrations, Transaction Logic & Reconciliation.
One failed integration can break the whole payment flow. When a payment fails, the system still needs a clear next step. One transaction should not have three different versions of the truth. We build the layer that fintech products depend on once they leave the demo stage: integrations with payment providers, banking rails, wallets and compliance services; transaction logic for retries, reversals, routing and fees; reconciliation across every connected system; and the internal tools that let operations teams work without calling an engineer.
Discuss your productWho this is for.
- 01
Fintech, payments and banking teams whose MVP works and now has to survive real volume, real providers and real support load
- 02
CTOs and heads of engineering adding providers, markets or payment flows to an existing product
- 03
Operations and finance leaders who need reconciliation, investigation tools and audit trails instead of spreadsheets
What's included
- 01
Payment provider, banking rail, wallet, payout and KYC/AML service integrations
- 02
Provider adapters and abstraction layers, webhook and event processing
- 03
Transaction state management: retries, timeouts, reversals, refunds, partial settlements, idempotency
- 04
Routing rules and fee calculation logic
- 05
Reconciliation: transaction matching, mismatch detection, exception workflows, reporting
- 06
Admin panels, transaction investigation tools, manual review queues, risk interfaces
- 07
Role-based access, audit trails and activity history
- 08
Backend architecture work to take an MVP to production readiness
How we build it.
Every external system has its own API behaviour, transaction states, timing and failure modes. We normalise them behind adapters with one contract, then model the product's own transaction lifecycle as an explicit state machine. Reconciliation runs as a first-class process that compares the ledger with each provider and routes differences into operator queues. The tooling is built around your existing architecture, roles and processes, not as a parallel platform. We do not sell payment processing or white-label platforms; we write the software that connects the ones you already use.
- 01
One adapter contract per provider type, so adding a PSP or rail is a bounded task
- 02
Idempotency keys on every external call; duplicate prevention at the ledger level
- 03
Reconciliation as a scheduled and event-driven process with exceptions routed to review queues
- 04
Operator tooling with role-based access and full audit trails from day one
Scope, timeline and budget.
Ranges are based on recent projects. After a discovery call we send a fixed estimate for the first milestone.
Integration sprint
- Timeline
- 4–8 weeks
- Budget
- from 20k USD
One or two provider integrations with transaction state handling, webhooks, retries and a monitoring view.
Production hardening
- Timeline
- 3–5 months
- Budget
- 60–150k USD
Integration layer refactor, transaction logic, reconciliation infrastructure, admin and investigation tooling, observability.
Team extension
- Timeline
- ongoing
- Budget
- monthly
Senior backend engineers embedded in your team for integrations, reconciliation and operational systems.
Frequently asked questions.
01Can you work inside our existing codebase?
Yes. Most of this work is done inside existing products. We start with an architecture and integration review, agree on contracts and then deliver in your repositories and pipelines.
02Which providers have you integrated?
Card acquirers and PSPs, open-banking and banking-as-a-service platforms, SWIFT and local clearing systems, mobile money, crypto custody and on-chain rails, and KYC/AML providers. The adapter approach means an unfamiliar provider is a bounded task rather than a risk.
03How do you approach reconciliation?
The ledger is the source of truth. We fetch statements and events from every provider, match them by reference, amount and status, flag mismatches and route each one into an operator queue with the context needed to resolve it. Reports and audit trails come out of the same data.
04Do you offer payment processing or a ready-made platform?
No. We provide custom software engineering. You keep your providers, licences and contracts; we build the integration, transaction and operational layers around them.
Planning something like this?
Tell us what you want to launch and when. An engineer will reply within 24 hours with questions, a draft scope and a realistic estimate.