Fintech API Integration Services – Banking, Payments & Trading
We integrate your product with Plaid, Yodlee, Stripe, Adyen, Bloomberg and 50+ fintech APIs. 120+ integrations delivered for neobanks, payment providers, robo-advisors, and trading systems — compliance-ready and engineered for reliability.

Types of APIs We Work With
Plaid, Yodlee, MX, FDX API — account linking (OAuth2), balance/transactions sync, webhook hardening, data normalization.
Stripe, Adyen, PayPal Braintree, ISO 8583 — tokenization, idempotency keys, 3-D Secure, multi-currency, reconciliation.
Bloomberg API, Refinitiv, FIX Protocol — real-time market data, order routing, execution reports, low-latency parsing.
Onfido, Sumsub, ComplyAdvantage — identity verification, AML screening, PEP/sanctions lists, audit trails.
Coinbase, Binance, Chainalysis — wallet integration, transaction monitoring, travel rule data exchange.
Where Fintech API Integrations Fail — and How We Fix Them
We provide end-to-end services to cover every aspect of API integration and management. Our core offerings include:
Lost transactions between core banking and payment gateways due to missing idempotency and unreliable webhooks.
Integration delays with Plaid/Yodlee caused by undocumented MFA refresh and account re-linking flows.
Compliance gaps from inconsistent KYC/AML data (Onfido/Sumsub), risking PSD2/GDPR issues.
Revenue loss during peak loads due to brittle payment gateway connections (Stripe, Adyen) and rate-limit breaches.
We typically stabilize these in days with robust retry queues, end-to-end observability, and compliance-first data flows.
Accelerate your business with expert API integration
It’s time to stop losing hours and dollars on manual work. Let us tailor an API integration solution that addresses your specific challenges and drives measurable results from day one.
Results We Deliver
- Stripe + Adyen bridge for a neobank: payment errors down from ~5% to ~0.1% with idempotency, retry queues, and unified transaction logs.
- Plaid integration for a PFM app: delivery time cut from ~3 months to ~3 weeks using pre-built modules for MFA refresh and webhook retries.
- Market data optimization: FIX message handling tuned; streaming latency reduced by ~80% for a trading platform.
Why Choose Itexus as Your API Integration Company
Our data and API integration services are designed to deliver real, tangible outcomes for your business. When you partner with us, you can expect:
Automate repetitive processes through smart API integration, freeing your team to focus on high-impact work.
Our API integration services reduce manual labor and operational inefficiencies, helping you save money at scale.
With reliable API connections, your data syncs automatically — no more mistakes from manual entry.
Access unified, up-to-date data across platforms through real-time API integrations that empower better decisions.
APIs connect your systems for faster service, accurate order updates, and personalized customer touchpoints.
Our API-driven solutions are built to grow with you — easily add new systems, apps, or data sources as you scale.
Ready to boost efficiency with API integration?
Whether you’re using popular cloud apps or specialized on-premise software, our expert API development and integration services can make them talk to each other seamlessly.
Our API Development and Integration Projects
PCI DSS-compliant application ecosystem for Coinstar, a leading international fintech company with $2.2 billion in annual revenue. This ecosystem features web and mobile crypto wallets, embedded kiosk software, and a cloud-based API server, enabling users to trade cryptocurrencies and over 50 digital assets, make crypto payments, and link their bank accounts for fiat-to-crypto conversions.
AI-based data analytical platform for wealth advisers and fund distributors that analyzes clients’ stock portfolios, transactions, quantitative market data, and uses NLP to process text data such as market news, research, CRM notes to generate personalized investment insights and recommendations.
How It Works: Our 4-Step Integration Process
Consultation & Planning
Design & Development
Testing & Deployment
Ongoing Support & Optimization
From start to finish, we handle the heavy lifting.
Book a consultationFAQ: Your API Integration Questions Answered
How much do API integration services cost?
Pricing depends on the scope and complexity of your project. We offer custom quotes for every integration. A simple integration between two well-documented systems might be on the lower end, whereas complex, enterprise-wide projects cost more. We provide a detailed estimate after initial consultation.
How long does an integration project take?
Project timelines vary based on requirements. A basic integration can take a few weeks, while more complex multi-system initiatives may span a few months. During the planning phase, we’ll give you a clear timeline. We’re experienced in working efficiently – and we won’t cut corners on testing or quality.
Will there be any downtime during the integration?
We strive to avoid or minimize downtime. Our team often uses a parallel deployment approach – building and testing the integration in a staging environment before going live. Any necessary switchover is scheduled during off-peak hours. In most cases, you won’t even notice an interruption. If downtime is required, we’ll inform you well in advance and keep it as short as possible.
Can you integrate our legacy or custom-built systems?
Yes. We specialize in integrating legacy, custom, and modern systems alike. If your older system doesn’t have a ready-made API, we can often create a custom connector or use middleware to enable communication. We’ve helped clients connect decades-old on-premise software with new cloud applications – extending the life of legacy systems and avoiding expensive replacements.
Do we need our own developers or IT team involved?
Not for the heavy lifting. Our service is end-to-end – we handle the design, development, and implementation. We do collaborate with your internal IT for things like obtaining access to systems or understanding specific business rules, but you won’t need to dedicate in-house developers to build the integration. After deployment, we can train your team on basic usage and provide documentation, so they’re comfortable with the new setup.
How do you ensure data security during integration?
Security is a top priority. We follow best practices such as using secure authentication (OAuth2, API keys), encryption for data in transit and at rest, and strict access controls. We also perform security testing on integrations. If your industry has compliance requirements (like HIPAA, GDPR, etc.), we incorporate those guidelines into the design. Your data remains safe and confidential throughout the process.
What types of software can you integrate?
We can integrate almost any software that offers an API – and even some that don’t (via database access or other methods). This includes CRM systems, ERPs, databases, payment gateways, marketing platforms, analytics tools, customer support systems, collaboration apps, and more. We stay up-to-date with a wide range of technologies and have likely worked with something similar to your stack. In short, if your team relies on it, we’ll make sure it’s connected.
What if a third-party API changes or breaks?
Part of our maintenance service is to monitor for any changes. If a software vendor updates their API (which can happen), we act quickly to modify the integration accordingly. Our modular design approach also means small changes won’t require redoing everything from scratch. We offer support plans so you’re covered in case something needs fixing – often we implement a patch before you even realize there was an issue.
Do you provide ongoing support after the integration is live?
Absolutely. We stand by our work with ongoing support and optional SLAs. You can count on us for help if you encounter any problems or have new needs. We can monitor performance, do regular health checks, and optimize as your usage grows. Think of it as having an integration partner on call. Many clients stay with us for years as their business evolves – adding new integrations or tweaking existing ones as needed.
How do we get started?
Getting started is easy – just reach out to us! We’ll begin with a conversation about your goals and systems (this consultation is free). From there, we’ll conduct a deeper analysis and then present you with a proposal including our solution approach, timeline, and cost. There’s no obligation until you’re ready to move forward. Once you approve, we schedule a kickoff and our team gets to work. Your integration journey could start today – we’re ready when you are.