Integration services for financial technology

Connect complex financial ecosystems without slowing the roadmap.

We design and modernise the integration layers that connect financial products with core systems, payments, partners and legacy technology.

Explore our integration capabilities
A Speednet engineer working on a laptop at an office desk.

Complex systems. One connected delivery layer.

  1. Core Systems
  2. Payments
  3. APIs
  4. Partners
  5. Middleware
  6. Legacy

Integration-first delivery for regulated environments

  • Financial institutions connected through one fintech platform25+

  • Microservices orchestrated across one digital ecosystem100+

  • Supplier integrations delivered for an award-winning BNPL platform19

  • Delivery squad connecting PSPs, payment schemes and core bankingOne

Key challenges

Where integration complexity slows delivery - and how we keep it moving.

The hard part is rarely connecting two APIs. The real challenge is coordinating systems with different ownership, release cycles, security models and business rules while keeping the customer-facing roadmap moving.

  • Every new product creates more dependencies

    A new payment method, lending journey or partner service often touches several internal and external systems before it reaches the customer.

    Treat dependencies as part of the product, not external blockers.

  • Legacy systems were not designed for today's roadmap

    Core and legacy platforms often expose limited interfaces, use older protocols or require workarounds that slow every new digital initiative.

    Modernise the integration layer without forcing a core replacement.

  • Every partner brings a different integration model

    Financial institutions, PSPs, identity providers, schemes and technology vendors differ in APIs, security requirements, certification and release processes.

    Absorb partner complexity behind a consistent integration layer.

  • Ownership gets fragmented across vendors and teams

    When frontend, backend, middleware and third-party integrations belong to different suppliers, problems often sit between contracts rather than inside one backlog.

    Create clear technical and delivery ownership across the whole flow.

  • Production is where integration risk becomes real

    Timeouts, retries, partial failures, data inconsistencies and dependency outages often emerge only under real production conditions.

    Design for failure, observability and recovery from day one.

  • Compliance affects how systems can connect

    Identity, data access, auditability, encryption and third-party risk requirements influence integration architecture long before implementation starts.

    Build security and control into the integration model.

Illustration of a brain made of circuit lines on an orange circle.

Integration capabilities

How we connect financial products to the systems and ecosystems behind them.

  • Core & legacy integration

    Extend digital products without waiting for a core transformation. Connect customer-facing platforms to core banking, policy, lending and other legacy systems through APIs, adapters, middleware and modern integration layers.

  • Payments & transaction integrations

    Connect payment capabilities across complex transaction flows. PSPs, payment schemes, account-to-account payments, embedded payments and other transaction services integrated into existing products and operational environments.

  • Partner & third-party integrations

    Add external capabilities without multiplying delivery complexity. Financial institutions, suppliers, identity services and technology partners connected through reusable and maintainable integration patterns.

  • API & middleware platforms

    Create a stable layer between fast-moving products and slower-moving systems. API-first services, orchestration, middleware and integration platforms that decouple customer-facing development from underlying systems.

  • Integration modernisation

    Replace fragile point-to-point connections without stopping the business. Incrementally modernise ageing interfaces, protocols and integration logic while existing products continue to operate.

  • Integration delivery teams

    Add specialist capacity or complete integration ownership. Individual backend and integration engineers or complete squads covering architecture, implementation, testing, partner coordination and production rollout.

Integration architecture

Point-to-point works until the ecosystem starts to grow.

As the number of systems, partners and channels increases, integration architecture determines whether new products can move independently or every release becomes a coordination exercise.

  • Direct integrations

    Simple where the dependency really is simple. Useful when there are few systems, stable interfaces and limited orchestration requirements.

    Best fit: Stable APIs · Low dependency count · Simple data flows

  • API & service layer

    Create clear interfaces around underlying systems. Expose business capabilities through APIs and services so customer-facing products do not need to understand every legacy dependency.

    Best fit: Digital channels · Core abstraction · Reusable business services

  • Middleware & orchestration

    Coordinate workflows across multiple systems and partners. Centralise transformation, routing, retries and process orchestration where multiple dependencies need to behave as one business flow.

    Best fit: Payments · Lending · Partner ecosystems · Multi-step transactions

  • Event-driven integration

    Decouple systems that should not have to move together. Use asynchronous events where real-time coupling would create unnecessary dependency and resilience risk.

    Best fit: High-volume processing · Notifications · Data synchronisation · Distributed platforms

Speednet team members laughing together in the office.

What products need

  • Fast change
  • Reliable data
  • Reusable services
  • Clear ownership

What the integration layer absorbs

  • Protocols
  • Partner differences
  • Legacy constraints
  • Failures
  • Routing
  • Security

Let's talk integrations

Adding another system should not slow down the whole roadmap.

Whether you're connecting a new partner, modernising legacy interfaces or building an integration layer across a growing ecosystem, we can help define the right architecture and delivery approach.

Talk to an integration expert

Our process

From dependency mapping to production integration.

We adapt to the environment you already have: existing systems, internal teams, external vendors, security processes and live customer journeys.

  • 1

    Map the ecosystem and dependencies

    We identify systems, owners, interfaces, data flows, security requirements, operational dependencies and the business journeys they support.

  • 2

    Define the integration model

    We decide what should connect directly, what needs abstraction, where orchestration belongs and which interfaces should be modernised or retained.

  • 3

    Build and coordinate across boundaries

    Our integration and backend specialists implement the solution while coordinating with internal teams, external vendors and dependent systems.

  • 4

    Validate end-to-end behaviour

    We test functional flows, failure scenarios, security controls, performance, data consistency and recovery across the complete integration path.

  • 5

    Release, observe and evolve

    We support production rollout, monitoring, stabilisation and further integration work as the ecosystem and product roadmap grow.

Case studies

See how we've connected complex financial ecosystems.

We've helped financial organisations connect systems, partners and payment flows without slowing product delivery.

All case studies

Integration as a growth layer

Every new financial product adds another system to the equation.

Banks and fintechs increasingly compete by combining capabilities from multiple internal platforms, financial institutions, payment providers and technology partners. The organisations that scale fastest are not necessarily the ones with fewer dependencies - they are the ones that manage them better.

  • Products are becoming ecosystems

    Modern financial journeys combine capabilities from multiple internal and external systems rather than one monolithic platform.

  • Partner speed becomes product speed

    A product roadmap can only move as quickly as its slowest critical dependency unless the architecture absorbs that complexity.

  • Reusable integration creates leverage

    Shared APIs, services and orchestration patterns reduce the amount of custom work required for every new channel, partner or product.

  • Integration ownership becomes strategic

    As ecosystems grow, somebody has to own the behaviour across system boundaries, not just the code inside individual components.

A Speednet team member smiling at a desk.

AI-assisted integration delivery

Use AI to understand and modernise complex integration estates faster.

AI can support code analysis, documentation, test generation, interface mapping and modernisation across large integration environments. Through governed AI-assisted workflows, we can accelerate this work while keeping code access, context and human approval under control.

AI-assisted delivery powered by Speedwave

Featured insight

Research and practical thinking for technology leaders.

Report cover: SuperApps in BankingReport cover: Value-Added ServicesReport cover: Banking trends 2025-2030

  • SuperApps in Banking: the potential, risks and development paths of SuperApps in European banking.

    Download for free

  • Discover the secrets to maximising the success of your banking software with our free ebook on value-added services.

    Download for free

  • Banking trends 2025-2030: 9 megatrends, 19 real-world implementations and 4 moonshot trends for financial institutions.

    Download for free

Integration insights

Ideas for connecting, modernising and scaling financial ecosystems.

Tech stack

Technologies we work with.

  • Integration

    REST · SOAP · Kafka · RabbitMQ · API Gateway

  • Backend

    Java · Kotlin · .NET · Node.js · Python

  • Platform

    Azure · AWS · Kubernetes · Docker · CI/CD

FAQ

Frequently asked questions about integration services for financial technology

  • What types of integrations do you build?

    We work across core and legacy systems, payment providers, financial institutions, partner APIs, identity services, middleware, data flows and other third-party platforms required by financial products.

  • Can you integrate new digital products with legacy systems?

    Yes. Most of our financial-sector work involves existing technology estates. We can use APIs, adapters, middleware and service layers to connect modern products to legacy systems without requiring a complete core replacement.

  • Can you modernise existing integrations incrementally?

    Yes. We can replace point-to-point connections, introduce reusable APIs, separate orchestration logic and modernise selected interfaces while existing products remain operational.

  • Do you work with payment integrations?

    Yes. Our experience includes payment providers, payment schemes, embedded payment flows and integrations connecting customer-facing financial products with surrounding banking systems.

  • Can you coordinate integrations with external vendors and partners?

    Yes. Integration delivery often requires coordination across multiple organisations. We can take responsibility for technical alignment, interface implementation, testing, dependency management and production readiness across those boundaries.

  • How do you handle failures and resilience across integrations?

    We design around real distributed-system behaviour, including timeouts, retries, idempotency, partial failures, monitoring and recovery. The exact approach depends on the criticality and architecture of the flow.

  • How do you approach security in financial integrations?

    Security requirements are considered as part of the integration architecture, including authentication, authorisation, data protection, encryption, auditability and the security standards of both internal and external systems.

  • Can you help us decide between direct integration, middleware and event-driven architecture?

    Yes. We assess the number and type of dependencies, transaction characteristics, resilience requirements, ownership model and future roadmap before recommending the appropriate integration pattern.

  • Can you work with our internal architecture and engineering teams?

    Yes. We can provide individual integration specialists, embed a squad within your existing organisation or take ownership of a defined integration workstream while following your architecture standards and governance.

  • Can you take an integration from design to production?

    Yes. We can cover architecture, implementation, vendor coordination, testing, security validation, production rollout, observability and post-launch stabilisation.

  • How do you use AI in integration projects?

    We use AI to support activities such as codebase analysis, documentation, interface mapping, test generation and modernisation. In regulated environments, these workflows can be governed through Speedwave to control code access, context, approvals and auditability.

  • Do you only provide integration services to banks?

    No. Banking and fintech are where we have the deepest integration experience, but the same capabilities apply to insurance and other complex environments where products depend on multiple systems, partners and legacy platforms.

Let's talk integrations

What's slowing your ecosystem down?

Tell us what you're trying to connect, modernise or simplify. We'll connect you with a Speednet integration expert and help define the right architecture and delivery path.

Michał Grela, a smiling man in a dark jacket

Michał GrelaHead of Growth

michal.grela@speednet.pl+48 600 023 843