Can you build open banking APIs for our institution?

Yes, including account information and payment initiation APIs with compliant consent and authentication flows.

How do you speed up partner API onboarding?

Through self-service developer portals with sandbox environments, clear documentation, and standardized authentication.

Can you modernize our legacy core without a full rewrite?

Yes, we wrap legacy cores with a modern API middleware layer, avoiding the risk and cost of a full core replacement.

How do you handle API versioning so partner integrations don't break?

We implement a formal versioning and deprecation policy with communicated migration windows, so partners get advance notice and a clear upgrade path rather than a surprise breaking change.

Can you help us pass an open banking certification review?

Yes, we build to the specific regulatory profile you're certifying under and test against those requirements before submission, rather than discovering gaps during the review itself.

Do you provide ongoing API governance, or just the initial build?

Both — we can hand off governance processes and documentation to your internal team, or continue managing gateway policy and partner onboarding under an ongoing retainer.

Software developer writing API integration code in VS Code and testing with Postman

API & Platform

API Integration & Open Banking Engineering

Banks, fintechs, and platform businesses run on APIs — and every unreliable integration becomes a partner escalation. Hurain Technologies designs, builds, and secures API ecosystems, from open banking connectivity to enterprise API management, so your partner integrations are fast to onboard, well-governed, and secure by default.

Get a Technical Estimate

Overview

What api integration & open banking engineering actually involves

Most organizations don't have an API problem so much as an API governance problem: individual teams built individual endpoints to solve individual problems, and a few years later there's no consistent versioning policy, no single source of truth for what's live, and no unified security model — just a sprawl of integrations that each partner has to be onboarded to separately. The fix usually isn't building more APIs; it's putting a coherent gateway, governance, and developer-experience layer over the ones that already exist, then extending it deliberately going forward.

Open banking adds a regulatory dimension on top of the technical one: account information and payment initiation APIs have to meet specific consent, authentication, and data-minimization standards, and the deadline to comply is rarely negotiable. We build to these standards from the API design stage rather than retrofitting compliance onto an existing integration, which is both faster and produces a cleaner audit trail when a regulator or partner asks to see one.

The Challenge

Problems we see teams struggling with

Slow partner and third-party onboarding

Without a proper API gateway and developer portal, every new integration takes weeks of custom engineering.

Inconsistent API governance

Multiple teams shipping APIs without standards creates versioning chaos and security gaps.

Legacy core system bottlenecks

Monolithic cores can't expose modern, well-documented APIs without a middleware layer.

Open banking compliance pressure

PSD2/open banking-style mandates require secure, standards-compliant APIs with strong consent and auth flows.

No visibility into API usage and abuse patterns

Without centralized gateway analytics, teams often don't know which partners are hitting rate limits, which endpoints are being scraped, or where latency is actually coming from.

Breaking changes disrupting live partner integrations

APIs shipped without a versioning strategy force partners into painful, uncoordinated migrations every time the underlying system changes.

Our Approach

How Hurain Technologies solves it

API strategy & governance

API design standards, versioning policy, and lifecycle governance so every team ships consistent, secure APIs.

Open banking API development

Account information and payment initiation APIs built to open banking standards with OAuth2/OIDC consent flows.

API gateway & management platforms

Implementation and consulting across MuleSoft, Apigee, WSO2, and Kong for traffic management, throttling, and analytics.

Middleware modernization

Wrapping legacy cores with modern, well-documented REST/GraphQL APIs without a risky core rewrite.

Developer portal & partner onboarding

Self-service developer portals with sandbox environments that cut partner integration time from weeks to days.

API security engineering

OAuth2/OIDC, mutual TLS, rate limiting, and API-specific threat protection against abuse and data exfiltration.

Versioning and deprecation strategy

A formal API lifecycle policy that gives partners predictable migration windows instead of surprise breaking changes.

Technology

Tech stack we work with

API Management

MuleSoft AnypointApigeeWSO2KongAWS API Gateway

Standards

RESTGraphQLOAuth2 / OIDCOpen Banking / PSD2-style standards

Backend

Java (Spring Boot)Node.jsGoKafka event streaming

Security

Mutual TLSAPI threat protectionRate limiting & quota management

The gateway is the control point for everything that matters operationally: authentication, rate limiting, request/response transformation, and analytics all pass through it rather than being reimplemented inconsistently inside each backend service. We select between MuleSoft, Apigee, WSO2, and Kong based on your existing infrastructure investment, team familiarity, and specific governance needs — there's rarely a universally correct choice, but there's usually a clearly correct one for a given organization's context.

For open banking specifically, the consent and authentication flow is the part most likely to go wrong: OAuth2/OIDC has to be implemented precisely to the relevant standard's profile, not just 'OAuth2 in general,' and the consent screens themselves need to make clear to end users exactly what data is being shared and with whom. We build these flows to the specific regulatory profile you're operating under and test them against the certification requirements before you submit for approval, rather than discovering a gap during the certification process itself.

Use Cases

Where api integration & open banking engineering gets used

Open banking account information APIs

Standards-compliant account data sharing APIs with proper consent flows for banks and fintechs meeting a regulatory deadline.

Payment initiation APIs

Secure, standards-compliant payment initiation endpoints that let authorized third parties trigger payments on a user's behalf with explicit consent.

Partner and fintech developer portals

Self-service onboarding with sandbox environments that cut partner integration time from weeks to days.

Legacy core API modernization

Wrapping a decades-old core banking or ERP system with modern, well-documented REST or GraphQL APIs without touching the underlying core logic.

Internal microservices API governance

Standardizing versioning, authentication, and documentation across internal teams shipping APIs independently, before sprawl becomes unmanageable.

API monetization platforms

Usage-based billing and tiered access infrastructure for businesses that sell API access as a product.

Proof

Results we've delivered

Client Result

A regional bank needed to launch an open banking API program to meet a regulatory deadline. Hurain Technologies delivered account information and payment initiation APIs on an Apigee gateway with a self-service developer portal, cutting fintech partner onboarding time from 6 weeks to 4 days.

Process

How an engagement runs

1
API landscape audit
We map existing integrations, pain points, and governance gaps.
2
Gateway & standards design
API management platform selection, standards, and security model defined.
3
Build & middleware development
APIs and middleware built, documented, and tested against partner use cases.
4
Developer portal launch
Self-service onboarding, sandbox, and documentation published for partners.
5
Monitoring & governance handover
Analytics, alerting, and governance processes handed to your internal team.

Engagement Models

How we structure the work

Open banking compliance sprint

A deadline-driven engagement to deliver certified, standards-compliant account information and payment initiation APIs.

Gateway implementation project

Selecting and implementing an API management platform (MuleSoft, Apigee, WSO2, Kong) as the governance layer over existing and future APIs.

Dedicated integration pod

An ongoing team handling partner integrations, middleware development, and API governance as your ecosystem grows.

Developer portal build

A focused engagement to launch a self-service developer portal with sandbox environments for partner onboarding.

Pitfalls

Mistakes we see teams make

Shipping APIs without a versioning policy

Every breaking change becomes a partner fire drill instead of a scheduled, communicated migration when there's no formal deprecation policy from day one.

Treating the developer portal as an afterthought

Partners judge integration difficulty by the documentation and sandbox quality as much as the API itself; a poor portal adds weeks to every onboarding.

Underestimating open banking consent UX requirements

Consent screens that are technically compliant but confusing to end users create support burden and can still fail a certification review focused on user comprehension.

No rate limiting until abuse actually happens

APIs launched without throttling are commonly discovered by scrapers and abusive clients before legitimate partners even find them.

Glossary

Key terms explained

API gateway: A control layer that sits in front of backend services, handling authentication, rate limiting, and routing for every request before it reaches your application logic.
OAuth2 / OIDC: Industry-standard protocols for delegated authorization and identity verification, used to let a user grant a third-party application limited access without sharing their password.
Open banking: A regulatory and technical framework requiring banks to expose standardized APIs for account data and payment initiation to authorized third parties, with explicit customer consent.
Rate limiting: Restricting how many requests a client can make in a given time window, used to protect backend systems from abuse or accidental overload.
Webhook: A callback mechanism where a service pushes event notifications to a URL you provide, rather than requiring you to repeatedly poll for updates.

FAQ