Payment Software Development
Services

Euristiq provides payment software development for fintech and SaaS platforms, marketplaces, digital lenders and e-commerce businesses. We build custom payment gateways, billing systems, and various payment platforms designed to meet your PCI DSS requirements. Every platform is AI-ready from the architecture up, so fraud scoring and other AI features can plug in later without a rebuild.
Our services

Payment software development services we deliver

Euristiq’s payment software development services cover the full lifecycle of a payment product: architecture, development, testing, launch and support. We build payment gateways, processing platforms, orchestration layers and payment apps, and modernize existing payment systems without stopping live transactions.
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Payment gateway software development

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Real-time payments and network integrations

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Payment processing platforms

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Payment platform modernization

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Payment orchestration and smart routing

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Cross-border and multi-currency payments

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Card issuing and embedded payments

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Digital wallets

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P2P and B2B payment platforms

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Fraud detection and transaction monitoring

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Billing, subscriptions and reconciliation

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Marketplace payments, payouts and PayFac

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Payment consulting and discovery

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Payment rail integration

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Embedded payments and BaaS

Payment gateway software development
PCI DSS-ready gateways built around your business model

Payment gateway development

As a payment gateway software development company, we start every gateway project with a build-or-integrate decision. We use Stripe and Adyen when they fit your model, and build a custom gateway when fees or routing control call for one. Our payment gateway software development services cover the full transaction path, including the moments when something goes wrong.

Stripe and Adyen integration with your checkout and ledger
Custom gateway builds with card tokenization, so raw card data stays out of your core systems
3-D Secure authentication flows for card-not-present payments
Idempotent retry handling, so a timeout or double click never charges a customer twice
Merchant dashboards for transactions, refunds, disputes and settlement reports
Unsure whether to build or integrate?
Real-time payments and network integrations
Payment infrastructure & integrations

Real-time payments and network integrations

We connect banks, networks and partners through secure, versioned APIs, and build hosted services so members don’t have to run their own infrastructure. Real-time rails and messaging standards are planned in from the start.

Open APIs and SDKs for member institutions
Hosted, multi-tenant network services
Real-time rails such as RTP, FedNow and SEPA Instant
ISO 20022 message mapping
Identity verification and consent flows
Book a call
Payment processing platforms
Built by an AWS Advanced Tier Partner for high-volume workloads

Payment processing platforms

We build the core that authorizes, captures, settles and refunds — on event-driven pipelines with a double-entry ledger, so every transaction can be traced and reconciled.

Authorization, capture, refunds and chargebacks
Double-entry ledger
Settlement and payout engines
Event-driven pipelines on Amazon SQS or Kafka
High availability and disaster recovery
Explore digital platforms for fintech
Payment platform modernization
Cloud-native payment architecture & migration

Payment platform modernization

We move payment and verification platforms off legacy cores, monoliths and blockchain ledgers onto cloud-native services — while live traffic keeps flowing. Partners migrate one at a time on a dual-rail setup, with a rollback path at every step.

Architecture assessment and migration roadmap
Monolith and ledger replatforming to microservices
Dual-rail cutover with rollback, partner by partner
Data migration with reconciliation checks
Performance and throughput engineering
Observability with OpenTelemetry and Grafana
Learn more about legacy modernization
Payment orchestration and smart routing
One API across providers, with failover built in

Payment orchestration and smart routing

An orchestration layer routes each transaction to the provider most likely to approve it at the lowest cost, and fails over when a provider goes down. You keep one integration for your product and one ledger for finance.

Multi-PSP and multi-acquirer routing
Cascading and failover on declines or outages
Cost- and approval-rate-based rules
Unified reporting across providers
Provider onboarding without product changes
Talk to a payments architect
Cross-border and multi-currency payments
PSD2, AML, and GDPR built in from day one

Cross-border and multi-currency payments

We build cross-border payment systems that hold, convert, and send money in multiple currencies across several rails. Sanctions and AML screening run on every transfer, so new markets don’t open new compliance gaps.

Multi-currency accounts and FX
Sanctions and AML screening
ACH, SWIFT, SEPA, FPS, and BACS rails
Plan your cross-border expansion
Card issuing and embedded payments
Card programs on Marqeta and Stripe Issuing

Card issuing and embedded payments

We help platforms launch their own cards and financial products through issuing processors and banking APIs, so payments become a revenue line instead of a cost.

 

Card issuing via Marqeta and Stripe Issuing
BNPL infrastructure
White-label banking APIs
BaaS platform development
Explore embedded payments
Digital wallets
Working wallet PoC in 2–4 weeks

Digital wallets

As a payment app development company, we build white-label wallets for fintechs and consumer brands that want stored value inside their own app.

White-label wallet apps for iOS and Android
Biometric authentication with step-up checks for high-risk actions
Card and bank account linking through Open Banking APIs such as Plaid and MX
Tap-to-pay and in-app checkout flows in the style of Apple Pay and Google Pay
Top-ups, transfers, withdrawals and balance history
Contact us
P2P and B2B payment platforms
Payment MVP live in 6–14 weeks

P2P and B2B payment platforms

We build platforms that move money between people and between businesses, from instant P2P transfers to B2B invoicing and bulk payouts. Approval workflows and open banking connections keep finance teams in control.

Instant P2P transfers
Maker-checker approval workflows
B2B invoicing and bulk payouts
Open banking integrations
Contact us
Fraud detection and transaction monitoring
ISO/IEC 27001:2022 certified security processes

Fraud detection and transaction monitoring

We add real-time fraud detection that scores every transaction before approval, combining rules engines with AI models. AML monitoring and dispute workflows keep losses and chargebacks under control.

AI-powered fraud detection in real time
AML transaction monitoring
Rules engines and risk scoring
Chargeback and dispute management
Audit your fraud controls
Billing, subscriptions and reconciliation
Month-end close without spreadsheets

Billing, subscriptions and reconciliation

We automate recurring billing and match every payment to bank and PSP reports, so finance closes the books faster and failed payments are retried before customers churn.

Recurring billing, proration and invoicing
Dunning and smart retries
Automated matching against bank and PSP files
Revenue and settlement reporting
Book a call
Marketplace payments, payouts and PayFac
Marketplace payments & payout engineering

Marketplace payments, payouts and PayFac

We build the money movement marketplaces need: split payments, seller onboarding, escrow-style holds, refunds and scheduled or instant payouts, with fees calculated per transaction.

Split payments and commission logic
Seller onboarding and KYB
Scheduled and instant payouts
Refunds, disputes and holds
Payout reconciliation
Discuss your marketplace payment needs
Payment consulting and discovery
1-week discovery sprint

Payment consulting and discovery

Before you commit a budget, we map your payment flows, providers, regulations and volumes. You get a build, buy or orchestrate recommendation, an architecture, and a cost and timeline estimate.

Payment flow and provider mapping
PCI DSS scope assessment
Build vs buy vs orchestrate recommendation
Architecture and migration plan
Estimate and roadmap
Book a discovery call
Payment rail integration
ACH, SWIFT, SEPA and FPS behind one API

Payment rail integration

Each rail has its own message formats and cut-off times. We integrate ACH, SWIFT, SEPA and Faster Payments (FPS) into one payment layer your product can call. Volumes make this work worth it: Nacha’s ACH volume statistics show ACH Network volume rose nearly 4.9% to 35.2 billion payments in 2025. In Europe, the European Union’s Instant Payments Regulation text required euro-area payment service providers to offer receiving instant euro transfers by January 9, 2025. Sending had to follow by October 9, 2025.

ACH origination and returns handling for US payments
SWIFT messaging for international wires
SEPA Credit Transfer and SEPA Instant for euro payments
FPS integration for UK domestic transfers
One internal API that hides rail differences from your product teams
Send us your project requirements
Embedded payments and BaaS
Card issuing via Marqeta and Stripe Issuing

Embedded payments and BaaS

Non-financial products can add payments or cards through banking-as-a-service (BaaS) partners. We build the product layer on top of those partners, so your team owns the user experience while the licensed partner handles the regulated activity.

Card issuing through Marqeta and Stripe Issuing
Buy now, pay later (BNPL) options at checkout
Embedded payment flows inside SaaS and marketplace products
White-label banking APIs for accounts and transfers
Add payments to your product

Payment software challenges we solve

New features are rarely the only thing payment teams need. These are the problems we’re asked to fix most often — and the ones that show up again and again across the payment projects we’ve worked on.
01

Legacy payment systems that can’t keep up

Batch jobs, monoliths or ledger nodes cap throughput and make every change slow and risky.

Batch processing
Monolith
Peak-load failures
Book a platform assessment
02

Migration risk on live payment traffic

You can’t stop payments to replace the platform, and your partners can’t rewrite their systems on your schedule.

Downtime
Partner changes
Rollback
See how we migrate
03

Failed and declined payments

False declines, provider outages and failed renewals cost revenue you’ve already earned.

False declines
Provider outages
Involuntary churn
Get a payment performance audit
04

Dependence on one PSP or acquirer

One provider sets your fees, your roadmap and your downtime.

Fees
Lock-in
Single point of failure
Compare PSP, custom and orchestration
05

Manual reconciliation and payouts

Finance matches bank files, PSP reports and payouts by hand, and month-end slips.

Spreadsheets
Split payments
Month-end close
Automate reconciliation
06

Compliance that keeps growing

PCI DSS scope, strong customer authentication, AML and SOC 2 requests land on engineering late in the project.

PCI scope
Audit trails
SOC 2 readiness
Map your compliance needs
07

Expanding into new markets

Each new country means new payment methods, currencies, rails and rules.

Local methods
Multi-currency
New rails
Talk to a payments architect
08

Fraud and chargebacks

Card-not-present fraud and disputes eat margin, while strict rules block good customers.

Chargebacks
Account takeover
False positives
Book a free AI workshop

Sounds familiar?

Let’s talk about your specific situation and see how our team can help.
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Our projects

Payment and fintech projects we delivered

Corporate travel payments
Identity and KYC
Investment platform

Payments and virtual cards for a B2B corporate travel SaaS

Payments and virtual cards for a B2B corporate travel SaaS

An Ireland-based corporate travel SaaS provider was held back by a monolith and a broken payment system. Euristiq re-architected the platform into microservices on AWS with Kubernetes, and integrated payments, expense management, and virtual card capabilities.
34%
increase in successful credit card payments
99.69%
platform uptime, up from 97.49%
2×
growth in unique users
View case study read more cta
corporate travel management web application corplay

Identity verification platform for Midy by Norton

Identity verification platform for Midy by Norton

Midy by Norton needed to verify identities at high volume without holding on to personal data. Euristiq helped build secure onboarding between mobile apps, microservices, and credential issuers, configuration APIs that change verification checks without code, and a Kafka backbone for high-volume events – the same KYC and fraud controls payment platforms need at customer onboarding.
100%
PII protection – verification data deleted right after processing
18+
microservices migrated from Amazon SQS to Kafka
3
OCR providers benchmarked in a Golang PoC
View case study read more cta
security verification support services for midy by norton - euristiq case study

Investment portfolio management platform for Octopus Investments

Investment portfolio management platform for Octopus Investments

Octopus Investments needed to replace an outdated portfolio management system. Euristiq led the full modernization: automated data collection across multiple sources, a redesigned investor portfolio flow, and secure payment processing integrated without disrupting day-to-day operations.
£12.9B+
in managed funds on the platform
63,000+
investors served
750+
employees using the system daily
View case study
enterprise investment management software modernization octopus
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Planning your payment MVP?

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Payment software development pricing

These are Euristiq’s general minimum engagements across all project types, and the closest comparable figures we publish for payment work. Your payment-specific estimate follows discovery, once rails and compliance scope are clear. Minimum engagement: PoC from $15,000 (2–4 weeks) · MVP from $25,000 (6–14 weeks) · Product development from $50,000 (4–12 months).

Payment Proof of Concept

Development
2-4 weeks
from $15,000
cost range
Book a call
Details
One technical hypothesis, such as gateway or rail feasibility
Working prototype
Architecture decision record
Free AI workshop

Payment MVP

Development
6-14 weeks
from $25,000
cost range
Request proposal
Details
Core payment flows
Authentication and role-based access
Subscription billing and basic admin
CI/CD and cloud deployment
Free AI workshop

Full platform

Development
4-12 months
from $50,000
cost range
Contact us
Details
Discovery and architecture
UX/UI and full-stack development
DevOps and cloud infrastructure
QA and security review before deployment

Hire fintech developers

Payment rails and providers we integrate

Payment rails

ACH
SWIFT
SEPA
FPS
BACS

Payment service providers

Stripe
Adyen

Card issuing and BaaS

Marqeta
Stripe Issuing
White-label banking APIs

Open banking and account data

Plaid
MX
PSD2 open banking APIs

Identity and KYC

Onfido (Entrust)
Biometric verification
OFAC screening
Sumsub
Veriff
Jumio

Core banking and ledgers

Mambu
nCino
LoanPro
Thought Machine
Temenos
Our approach

We deliver payment software with
the 4D solutions framework

Fixed-price discovery

Discover

We map your payment flows, providers, rails, volumes and regulations.

Payment flow map
PCI scope assessment
Build / buy / orchestrate recommendation
Estimate
Architecture before code

Decide

We design the ledger, event model, security controls and, for existing systems, the migration path.

Architecture and ledger design
Dual-rail migration plan with rollback points
Compliance control map
Working PoC first

Design

Two-week sprints with demos: a working PoC, then the MVP or the first migrated slice.

Clickable prototype
PoC
MVP or first migrated partner
Phased cutover

Deliver

Parallel runs, partner-by-partner cutover, monitoring, and support matched to how critical the system is.

Partner onboarding plan
Certification support with acquirers and schemes
Runbooks
SLA-backed support
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Types of payment systems we build

Our payment solution software development starts from your business model, because a marketplace and a subscription product break in different places.
01

E-commerce checkout

Checkout conversion depends on speed and on few steps between cart and confirmation.

Card and wallet payments with saved, tokenized methods
3-D Secure with frictionless flows where the issuer allows
Guest and one-click checkout
Duplicate-charge protection on retries
Plan your checkout flow
02

Marketplace and multi-party payouts

Marketplaces collect from buyers and pay many sellers, so funds must be split correctly and released on schedule.

Split payments and platform commission logic
Seller onboarding with KYC checks
Scheduled and on-demand payouts
Payout reconciliation and seller statements
Map your payout flow
03

SaaS subscription billing

SaaS teams need billing that tracks plans and usage, built on Stripe or a custom engine.

Recurring billing with tiered and usage-based pricing
Usage metering tied to your product events
Failed renewal recovery
Revenue data sync with finance systems
Talk through your pricing model
04

Cross-border remittance

Remittance products compete on fees and delivery time in each corridor.

Corridor-specific rail and partner routing
FX quotes locked at confirmation
Sanctions and AML screening
Recipient notifications and status tracking
Book a call
05

In-app and mobile wallets

Wallets keep users inside your app for payments and stored values.

Swift, Kotlin, React Native or Flutter builds
Biometric login and step-up authentication
Bank account linking through Plaid and MX
P2P transfers and top-ups
Build your in-app wallet
06

Embedded finance in non-financial products

Software platforms can add payments or cards through BaaS partners, with us building the product layer your users see.

Card issuing through Marqeta or Stripe Issuing
BNPL at checkout
Payment acceptance for your customers’ own customers
Partner and compliance reporting
Add cards to your platform

Our tech stack

Backend

Mobile

Web frontend

Legacy

Blockchain/DeFi

Data & AI/ML

Observability

Backend
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Java
C#/.NET
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Python
Go (Golang)
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Node.js/TypeScript
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Kotlin
Rust
C++
Ruby
PHP
Elixir
Erlang
Mobile
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Swift
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Kotlin
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React Native/TypeScript
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Flutter/Dart
Objective-C
Web frontend
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JavaScript/TypeScript
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React
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Vue.js
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Angular
Legacy
COBOL
Java
PL/I
RPG
Blockchain/DeFi
Solidity
Rust
Go
Move
Vyper
Haskell
Data & AI/ML
Python
SQL
Scala
Julia
MATLAB
PL/SQL
Observability
OpenTelemetry
Prometheus
Grafana
Loki
Tempo

FAQ

What payment software development services does Euristiq offer?

We build payment gateways, digital wallets, P2P and B2B payment platforms, cross-border and multi-currency systems, recurring billing, and payment orchestration layers. We also modernize legacy payment cores and integrate PSPs such as Stripe and Adyen. You can start with a PoC, an MVP, or a full platform build.

Do you build payment software for the Canadian market?

Yes. We’re headquartered in Toronto, work with Canadian AWS regions, and design for PIPEDA and FINTRAC requirements. Our team has replatformed part of Canada’s national payment infrastructure, and most of our payment engineers work in Java, the stack Canadian banks and fintechs run on.

How much does payment software development cost?

A payment PoC starts at US$15,000 (about CA$21,000), an MVP starts at US$25,000 (about CA$35,000), and a full platform starts at US$50,000 (about CA$70,000). The main cost drivers are the number of providers and rails, the markets you serve, and your PCI DSS scope. A discovery sprint gives you a fixed estimate.

Can you modernize our payment system without disrupting live transactions?

Yes. We run the old and new platforms side by side on a dual-rail setup and move partners or traffic in stages, with a rollback path at each step. For a national verification network in Canada, banks migrated one at a time in a single weekend window each, with no code changes on their side.

How do you handle PCI DSS and payment security?

We keep card data out of as much of your system as possible with tokenization and hosted fields, then design the rest around PCI DSS, strong customer authentication and encryption. Every change goes through code review, static and dynamic tests, and vulnerability scans in CI — the same gates our enterprise clients require.

Can you help us prepare for SOC 2 or ISO 27001?

Yes. We work in two layers: cloud configuration, scanning and fixes first, then controls in the code itself, such as access, logging and data handling. Euristiq is ISO/IEC 27001:2022 certified, so we know what auditors ask for.

Do you use AI in development, and how do you keep payment code secure?

Yes. AI-native delivery shortens PoC and MVP timelines. For production payment systems, AI-assisted code follows our AI-SDLC standards and passes the same human review, testing and security gates as any other change.

Who does Euristiq build payment software for?

Payment software looks different for a bank, a PSP and a SaaS product. We’ve built for all of them, so the architecture starts from how your money actually moves:

 

Banks, credit unions and payment networks: modernize payment and identity infrastructure without interrupting live traffic or asking member institutions to rewrite their systems.
PSPs, acquirers and PayFacs: add payment methods, rails, routing and markets without rebuilding your processing core.
Fintech startups and scale-ups: launch a compliant payments MVP fast, on an architecture that won’t block your next funding round or your first audit.
Marketplaces and platforms: split payments, onboard sellers and pay them out across currencies, with reconciliation your finance team can trust.
SaaS and vertical software: embed payments in healthcare, insurance, travel, mobility or education software, and turn them into a revenue line.
Enterprises with complex payment operations: bring several providers, bank files and payout flows under one ledger, with fewer manual steps at month-end.

What core features does Euristiq build into payment software?

Whether you’re launching a payment product or adding payments to an existing platform, these are the capabilities Euristiq designs for, so each step hands clean, traceable data to the next:

Payment acceptance: cards and digital wallets; ACH, SEPA, SWIFT and FPS; hosted and embedded checkout; recurring and one-click payments; multi-currency pricing.
Security and authentication: tokenization and card vault; 3DS2 and SCA; OAuth 2.0 and OpenID Connect; encryption at rest and in transit; role-based access.
Ledger, settlement and reconciliation: double-entry ledger; settlement and payouts; automated reconciliation; refunds and chargebacks; fee calculation.
Risk and compliance: real-time fraud scoring; KYC/KYB onboarding; AML transaction monitoring; sanctions screening; full audit trail.
Reliability and operations: idempotent APIs and safe retries; provider failover; monitoring, tracing and alerting; merchant and admin dashboards; data warehouse export.

What engagement models does Euristiq offer for payment software development?

Pick the model that fits where your payment product is today: AI-accelerated MVPs on a fixed scope, or enterprise delivery with full security and compliance gates on time and materials.

End-to-end payment platform development: Euristiq delivers the product from scratch: discovery, architecture, build, launch and support.
Team extension: you lead; our payment and Java engineers help you release faster without lowering the bar.
CTO as a Service: senior technical leadership for payment projects without an in-house CTO.
AI solutions architect: find where AI pays off in your payment product, from fraud scoring to support automation.

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    Let’s talk!

    Ivan Muts, President of Euristiq
    Contact euristiq custom software development company