Modern Trading Architecture Requires a Buy AND Build Approach

Modernizing trading technology is no longer a simple choice between buying vendor systems or building everything in-house. For many firms, the stronger strategy is a hybrid one: buy the foundation, then build the workflows, applications, and experiences that create differentiation.

That was the focus of the recent A-Team Group webinar, “How to move to a modern, component-based trading architecture using a Buy AND Build approach,” featuring Bob Myers, Chief Product Officer at interop.io, alongside leaders from Clear Street and Prospera Fund Partners.

The discussion centered on how trading firms can move away from fragmented, monolithic environments and toward more flexible architectures where vendor systems, internal applications, data tools, and AI-enabled capabilities can work together as part of a connected desktop experience.

Buy vs. build is really about time, risk, and focus

One of the key themes from the discussion was that buy vs. build decisions should not be framed only around cost. Firms also need to consider how quickly they need to move, how much execution risk they are willing to take on, and where internal development resources can create the most value.

“For me, buy versus build was never really a cost decision. It’s a time and risk decision.”

This is especially relevant in trading environments, where teams are under pressure to modernize quickly without disrupting the systems users already rely on. Building every layer of a modern desktop architecture in-house can consume valuable time and talent that might be better spent on firm-specific workflows and client-facing innovation.

The hybrid approach allows firms to buy proven platform capabilities — such as interoperability, workspace management, context sharing, application orchestration, and standards support — while continuing to build the components that differentiate the business.

Start with the workflow, not the technology

Another important takeaway was the need to begin modernization projects with a clear understanding of the user experience. Before firms decide what to build or buy, they need to understand how traders, portfolio managers, operations teams, and other users actually work.

Bob emphasized the importance of starting with the desktop itself:

“I always recommend that folks actually start with the user interface and the screen real estate.”

That means mapping the workflows users need to complete, the applications they rely on, the data they need in context, and the points of friction that slow them down. From there, technology teams can work backward into the architecture required to support those workflows.

This approach helps firms avoid modernization efforts that look successful technically but fail to improve the day-to-day experience of the people using the platform.

Interoperability is the foundation for component-based architecture

A modern trading architecture depends on the ability for applications to work together. That includes vendor systems, internally developed tools, web applications, native desktop applications, legacy systems, and emerging AI capabilities.

In this environment, interoperability should not be treated as a one-off integration project. It needs to function as a platform layer that allows applications to participate in shared workflows over time.

With the right interoperability foundation, firms can connect applications at the user experience level, share context between systems, reduce manual rekeying, and create more coordinated workflows across the desktop. This is what makes a component-based architecture practical: applications can remain modular while still functioning as part of one connected environment.

Open standards help reduce complexity

The panel also discussed the importance of standards such as FDC3. In complex trading environments, open standards can help normalize how applications share context and trigger actions across systems.

Bob noted:

“Standards are incredibly useful like FDC3 that just take some of the guesswork out of how you’re actually gonna normalize or agree upon this broadcasted context.”

For firms working with a mix of internal tools and third-party applications, standards can also influence vendor selection. Applications that are already standards-enabled are easier to connect into a broader platform strategy, reducing the need for custom integration work.

Modernization does not have to mean rip and replace

A recurring message throughout the webinar was that firms do not need to replace everything at once. In many cases, the most practical path is to preserve the applications and systems that still work, while building a modern interoperability layer around them.

This approach helps firms reduce disruption, accelerate delivery, and create a better foundation for future innovation. It also gives technology teams more flexibility to modernize progressively rather than waiting years for a full platform rebuild.

That flexibility matters as firms begin thinking about AI strategy. AI is only useful in real workflows if it can access the right context, interact with the right applications, and operate within a governed desktop environment. A connected, interoperable architecture gives firms a stronger foundation for bringing AI into the workflows users already trust.

The takeaway

The future of trading architecture is not buy or build. It is Buy AND Build.

Firms need the freedom to build what makes them unique, but they also need a proven foundation that helps them move faster, reduce risk, and connect the systems users depend on every day. By starting with the workflow, adopting open standards, and using interoperability as a platform strategy, firms can modernize without unnecessary disruption — and create a more flexible foundation for what comes next.

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.