API Modernisation for a Private Bank

The challenge: the bank needed to modernise its fragmented and fragile API landscape in order to compete with digital-first institutions, integrate legacy systems with modern front-end services, and provide the seamless experience today’s customers expect. At the same time, it was essential to preserve the bank’s heritage, reputation, and commitment to compliance.

Saros worked with internal engineering, security, and operations teams to design and implement a secure, scalable API-led architecture that would support both present needs and future innovation.

The Challenges

• Outdated, brittle API ecosystem with minimal test coverage and poor documentation
• Fragmented integrations between legacy databases and digital services
• Rising customer expectations for modern online and mobile banking experiences
• Compliance and security requirements critical in financial services
• Need for sustainable development practices after the departure of the incumbent systems integrator

The Solution

Saros Consulting applied a structured approach to stabilise and modernise the bank’s integration layer:

• API-led connectivity using Mule 3, layered into system, process, and experience APIs
• Secure integrations with third-party services including behavioural biometrics and identity verification
• Engineering discipline introduced through behaviour-driven development, Liquibase for database change management, and CI/CD pipelines with Jenkins
• Governance and quality reinforced through peer reviews, automated testing, and traceability
• Knowledge transfer via workshops, runbooks, documentation, and ongoing developer pairing to build in-house capability

The Results

The modernised API platform enabled the bank to:

• Offer secure, reliable digital channels for customers to manage accounts, transfer funds, and authorise transactions
• Accelerate delivery of new features through reusable API assets and predictable deployment patterns
• Strengthen compliance, traceability, and resilience of core banking operations
• Build confidence in the bank’s digital roadmap, ensuring future capabilities could be developed with agility

Why It Matters

This programme brought a heritage financial institution into line with market expectations, enabling it to compete with digital-first banks without compromising trust or alienating its traditional customer base. The new API-led foundation balanced modernisation, compliance, and customer experience, critical for long-term competitiveness in financial services.