Rethinking the core: Why BIAN is banking’s quiet revolution

There’s no shortage of pressure on banks right now. Between tightening regulations, rising operational costs, surging customer expectations, and nimble competitors redefining what “good” looks like, the industry is feeling the squeeze.

Add legacy systems to that mix and you've got a problem. Not a small one; a “can’t launch new products, can’t personalise experiences, can’t integrate without headaches” kind of problem. Modern banking needs modern foundations. That’s where BIAN comes in.

BIAN 101: What it is and why it matters

Short for the Banking Industry Architecture Network, BIAN is a global standard for how banking systems should be structured, connected and understood. It gives banks a shared language, a set of modular building blocks (called service domains), and standardised APIs to help systems talk to each other, internally and externally, without endless custom development.

In practice, BIAN makes banking architectures easier to integrate, quicker to adapt, and cheaper to run. It's not just about fixing tech. It's about enabling your business to move faster, scale smarter, and deliver better experiences without reinventing the wheel each time.

What’s driving adoption?

Banks aren’t adopting BIAN because it’s trendy. They’re adopting it because:

• Legacy systems are unsustainable. They’re brittle, expensive, and create massive innovation bottlenecks.

• Open banking and BaaS are non-negotiables. You need interoperable, API-ready platforms to play in modern financial ecosystems.

• Regulations are getting more complex. BIAN’s structure supports better governance, auditability, and data clarity.

• Customer expectations keep rising. And you can’t personalise anything without clean, consistent, connected data.

BIAN gives you a framework to modernise strategically: starting small, proving value, and scaling with confidence.

From ‘bank as a black box’ to composable, modular platforms

Traditionally, core banking systems were built like monoliths - tightly coupled, hard to change, and nearly impossible to update without breaking something else.

BIAN flips that. It encourages composable architecture, where functions are modular and loosely coupled, so you can evolve one capability (like customer onboarding or payments) without disrupting the rest.

This unlocks all kinds of business value:

• Want to test a new FinTech partnership? You can.

• Need to launch a new product fast? Go for it.

• Looking to consolidate redundant services across divisions or regions? Done.

And it’s not theoretical

Banks around the world are already putting BIAN to work:

• PNC used BIAN to map its entire app landscape and develop a set of internal APIs, cutting through complexity and reducing vendor lock-in

• HSBC is leveraging BIAN to future-proof its global technology architecture, enabling scale and speed without chaos

• And in South Africa, banks such as Absa and Standard Bank are also BIAN members.

These examples show how banks are using BIAN as part of their core strategy, not just as a side initiative. 

BIAN, BOMs and business outcomes

At the heart of BIAN is the Business Object Model (BOM), a standardised data language that helps different systems interpret information the same way. That’s not just a technical win. It’s a business enabler.

When you have consistent, well-defined data models across the bank, you can:

• Create a single view of the customer

• Speed up regulatory reporting

• Power AI and analytics with clean, reliable data

• Build new products and services faster

In other words: BOMs make your systems smarter, your teams faster, and your data usable.

This isn’t a ‘rip and replace’ move

Let’s be clear: BIAN isn’t about throwing out what you have. It’s about modernising at your own pace, layering in standardisation where it makes the most impact, and evolving towards a future-ready architecture.

You don’t have to be a global bank to benefit. If you’re grappling with siloed systems, inconsistent data, or bloated integration projects, BIAN gives you a path forward.

And it’s not just for IT. Business leaders gain agility, speed, and control, alongside a clear architectural roadmap that supports long-term strategy.

Where BBD fits in

At BBD, we’re working alongside banking clients across the globe to put BIAN into practice, translating the framework into real-world functionality. 

Together, that can mean: 

• Mapping current architectures to BIAN’s service landscape

• Identifying opportunities for consolidation, automation and innovation

• Designing APIs and developer experiences that are secure, scalable and standardised

• Implementing modular platforms that grow and evolve over time