Payment Systems
Built to Process
Without Failure.
We build Scala payment infrastructure on the JVM where correctness is enforced by the type system, not by careful manual testing. Transaction engines, settlement systems, and payment API integrations built for companies where getting it wrong is not an option.
JVM.
Native performance
0x
Tolerance for race conditions
Scala 2+3
Ecosystem coverage
FP.
Correct by construction
Why Scala for Payment Systems
Payment systems demand a language where
incorrect states are impossible.
Transaction architecture
How a payment flows through
a Scala-built system.
Initiation
http4s + Tapir
Authorization
Cats Effect
Event emission
Kafka / Akka
Ledger update
Doobie
Settlement
Apache Spark
Confirmation
FS2 / Circe
What we build
Scala payment systems capabilities.
01
Transaction processing
High-throughput payment processing on the JVM.
We build transaction processing engines that handle high volumes of payments, transfers, and authorizations with the correctness guarantees and latency profiles that production payment platforms require. Built on Scala with Cats Effect and ZIO for the concurrency model that payment flows demand.
02
Payment API integration
Type-safe integrations with payment providers and banking APIs.
We build the integration layers that connect Stripe, Adyen, Braintree, and banking APIs to your core platform. Type-safe, well-tested, and built to handle the partial failures and inconsistent responses that external payment APIs routinely produce under real load.
03
Settlement and reconciliation
Batch settlement and reconciliation at scale.
We build settlement and reconciliation systems on Apache Spark and Scala that process high volumes of transactions against payment provider records, flag discrepancies, and produce the audit-ready output that finance teams and regulators require.
04
Ledger and accounting systems
Immutable double-entry ledgers built for financial accuracy.
We build ledger systems with immutable transaction records, idempotent writes, and the double-entry accounting logic that financial platforms depend on. Transaction-level consistency guarantees and the audit trails that compliance requires.
05
Payment orchestration
Routing, retry logic, and fallback for complex payment flows.
We build payment orchestration systems that route transactions across multiple providers, handle retries with idempotency guarantees, and implement fallback logic when primary payment paths fail. Built for the resilience that production payment orchestration requires.
06
Compliance infrastructure
Regulatory reporting and audit trail systems.
We build the compliance infrastructure that payment platforms need to satisfy PCI DSS, PSD2, and regulatory reporting requirements. Immutable event logs, traceable state transitions, and domain modeling that makes regulatory requirements expressible in code.
Built for correctness
The four properties every
payment system must have.
01
Idempotency
Every payment operation is safe to retry. No double charges, no duplicate records, no inconsistent state from network failures.
02
Consistency
Ledger balances and transaction records are always in sync. No partial writes, no orphaned records, no state that requires manual reconciliation.
03
Auditability
Every state transition is recorded and traceable. Regulators, auditors, and your own engineering team can reconstruct what happened and when.
04
Resilience
Payment flows degrade gracefully when providers fail. Retries, fallbacks, and circuit breakers built into the architecture, not patched in after the first incident.
Common questions
Questions we get before the first call.
If your question isn't here, it takes one conversation to answer it.
Talk to us →Do your engineers have experience with production payment systems, not just Scala generally?
Yes. We specifically match clients with engineers who have production experience with payment infrastructure, including transaction engines, ledger systems, and settlement pipelines.
Can you work with our existing payment provider integrations?
Yes. Whether you're already integrated with Stripe, Adyen, Braintree, or a banking API, our engineers work with your existing integrations and extend them. We don't require you to swap providers or change what's already working.
We have a legacy Java payment system. Can you migrate it to Scala incrementally?
That's one of the most common situations we work in. Scala runs on the JVM and interoperates directly with Java, so we can migrate service by service without a big-bang rewrite. We modernize the parts that are causing problems first.
How quickly can engineers be contributing to our codebase?
Most engineers are contributing to active work within days of the engagement starting. We don't do multi-week onboarding periods. Engineers come in knowing the ecosystem and start with real work from the beginning.
Do you work on greenfield builds or only existing systems?
Both equally. Some clients are building a new payment platform from scratch. Others need engineers to improve, extend, or stabilize what they already have. The engagement model adjusts to the situation; we don't have a fixed delivery pattern we push everyone into.