Buy vs Build Your Financial Application Platform: Why the Smart Strategy Is Both

Financial institutions modernizing their technology often face a familiar question: should they buy a platform or build one internally?
As systems become more complex and workflows span multiple applications, that choice is no longer binary. Increasingly, the most effective strategy is not buy vs build, but buy and build.

When financial institutions modernize their technology, the first instinct is often to focus on applications. New web interfaces, new vendor tools, new analytics platforms, and increasingly, AI capabilities.

Eventually, the conversation shifts to a more holistic question: the platform itself.

How should all these applications work together?
Who owns the orchestration layer?
How do workflows evolve over time?

That’s when the familiar “buy vs build” debate used to begin. But today, the conversation is changing (check out our recent conversation with T.Rowe Price from TradingTech’s recent Buy AND Build conference).

For T.Rowe Price and many teams focused on platform building, “buy and build” is becoming the default approach. The choice is no longer binary. Either you purchase a commercial platform and accept its constraints, or build the entire infrastructure internally and maintain full control. In practice, neither extreme fully serves modern platform teams — particularly in financial services, where systems span web, desktop, legacy environments, and now AI-driven workflows.

The more effective strategy today is buy and build.

Understanding What You’re Actually Building

When teams decide to “build a platform,” what they are really committing to is far more than a user interface.

They are building:

Shell architecture
Inter-application communication frameworks
Context-sharing mechanisms
Workspace and layout management
Lifecycle management
Security controls
Upgrade and compatibility management

None of this work is trivial. More importantly, none of it is ever finished.

Building an interoperability layer becomes permanent infrastructure. It requires ongoing engineering resources to maintain performance, manage security updates, adapt to new browser or framework versions, and support new vendors and standards.

Many firms start with the goal of control and customization. Over time, however, they find that a significant portion of their engineering capacity is devoted to maintaining plumbing rather than delivering differentiated value.

At the same time, buying a rigid, closed SaaS platform is not an appealing alternative. Financial institutions need flexibility. Vendor landscapes change. Regulatory requirements evolve. AI capabilities are reshaping workflows faster than most roadmaps can keep up.

The real question, then, is where to invest engineering effort.

Where Should Your Engineers Create Value?

Modern financial platforms must support complex, evolving workflows. They must allow applications to share data in real time, coordinate user context, and enable action across systems. Increasingly, they must also allow AI to operate across multiple applications rather than being confined to a single tool.

All of this can be built internally. The question is whether that is the highest-value use of your engineering team. Every month spent building shell architecture and communication layers is a month not spent improving trading workflows, advisor experiences, automation, or AI-driven insights.

This is where a hybrid approach becomes compelling.

Buy the Foundation. Build the Differentiation.

With io.Connect, firms are not purchasing a closed application platform. They are adopting an interoperability foundation — one that handles orchestration across web, desktop, and legacy applications, and supports standards such as FDC3.

On top of that foundation, platform teams continue to build.

They design their own unified desktop experiences.
They define custom workspaces and layouts.
They create logical team groupings and quick-action panels.
They integrate proprietary tools and AI capabilities.

The image below illustrates one such implementation. The team did not simply deploy an off-the-shelf platform. They assembled their own tailored experience, combining custom workflows, micro UIs, real-time notifications, and access controls — all built on top of an interoperability layer that removed the need to engineer core plumbing from scratch.

This is not a “buy and accept limitations” model. It is a buy to accelerate, build to differentiate model.

io.Connect: The Platform for Continuous Change

One of the most common concerns about buying infrastructure is vendor lock-in. In reality, lock-in often emerges from custom internal builds as much as from commercial products. Architecture decisions, once embedded, can be expensive to reverse.

An open, standards-based interoperability layer changes that dynamic. It allows firms to integrate new vendors, replace existing ones, and introduce AI capabilities without rewriting foundational components. It provides flexibility without forcing the organization to maintain every layer of infrastructure internally.

This flexibility is particularly important now. AI is not a single feature that can be bolted onto one application. It requires access to context, workflows, and actions across systems. A platform that can evolve — rather than one that is frozen around yesterday’s architecture — is becoming a competitive necessity.

Speed Today, Evolution Tomorrow

The hybrid approach delivers two forms of return on investment.

First, it accelerates time to market. Teams avoid 18–24 months of foundational development and can move more quickly to production.

Second, it preserves long-term flexibility. Because the infrastructure layer is purpose-built for interoperability and continuously maintained, internal teams remain free to focus on building differentiated experiences that evolve as the business evolves.

“The actual build and connectivity part that interop.io helps support was around four or five months. And, you know, I’ve had many years of transformation experience. I can’t believe how quickly they did this.”
— Dan Green, T. Rowe Price

The Smart Decision Is Rarely Binary

The traditional buy vs build framing oversimplifies a far more nuanced decision. Financial institutions do not need to choose between rigid SaaS platforms and building every component themselves.

They can adopt a foundation designed for interoperability and continue building the platform that reflects their unique workflows, teams, and strategy.

Interoperability is more than just a technology initiative; it’s a strategic framework for continuous innovation.

For organizations evaluating this decision, we have put together a detailed guide outlining implementation timelines, three-year cost comparisons, and the long-term risks that often go underestimated.

If your team is currently weighing whether to build a financial application platform internally or adopt a hybrid model, you can download the full Buy vs Build decision guide here.