The Hidden Costs of Heritage UI

Heritage Pega applications were built in a different era, for different demands. In their time they were cutting edge – indeed, the fact they can still provide a good service today is testament to how advanced they were at the time. However, in today’s fast-evolving market, they often can’t deliver the required flexibility and performance without significant rework.

1. Maintenance Drag

While custom code was one of the biggest benefits of heritage systems, it often bypasses Pega’s guardrails. This means that every platform update risks breaking those changes, forcing teams to spend time reworking existing code.

2. Slower User Experience

Heritage server-rendered pages require the app to build the entire layout on the back end for each click. That increases server CPU and memory use, raising cloud costs and slowing response times under load, which harms UX.

3. Compliance Risk

Meeting WCAG 2.2 AA accessibility standards and modern security standards takes ongoing effort when you’re retrofitting them into a legacy front end. Existing and proposed regulations in the US, UK, and EU make this a growing risk. Read more about compliance here. 

4. Talent Attraction & Retention

Modern front-end engineers want to work with frameworks like React or Angular. Older JSP-based UIs can make it harder to recruit and keep top talent. In light of the ever-growing tech skills gap, this should be a major concern.

5. Strategic Opportunity Cost

Time spent keeping heritage UI functional is time not spent delivering new features, improving user journeys, or entering new markets.

What's Different with Constellation? 

Constellation is built on a client-side engine that renders UI in the browser rather than on the server. That changes how apps are built, how they perform, and how they scale.

• App studio first – A low-code design environment that allows business and IT teams to collaborate without deep coding
• Templated design system – Standard, reusable components ensure branding consistency, mobile responsiveness, and WCAG 2.2 AA compliance
• Lean DX API v2 – Efficient, model-driven API calls deliver only the data and layouts needed, enabling micro front ends, embedded self-service widgets, and progressive web apps
• Upgrade-ready architecture – Built to minimize breakage during platform updates, reducing regression-testing effort

In short, Constellation makes apps faster, simpler to maintain, easier to enhance, and less dependent on specialist custom code.

You can learn more in this video from Pega, which takes a deep dive into the technical features of Constellation.

Why This Matters to Your Business 

Constellation’s technical upgrades act as remedies to the hidden costs outlined earlier in this article. As such, they translate into tangible business outcomes, such as:

• Higher efficiency – Faster screens mean more cases can be processed per day, directly affecting service levels and operational cost
• Improved customer journeys – Consistent, responsive interfaces reduce drop-off and shorten resolution times
• Lower hosting costs – Reduced server load means you can run the same workload on reduced cloud resources
• Simpler upgrades – With fewer customizations to maintain, upgrades become faster and less disruptive
• Reduced compliance effort – Accessibility and security are built in, reducing remediation work and audit costs

Constellation Adoption to Suit You

Pega Modernization can feel like a big step. With so much involved and so much at stake, it can be easy to feel overwhelmed. However, it doesn’t have to be as disruptive as it sounds.

With sound planning it is possible to plot the perfect Modernization roadmap for your business.

You could start with one or two high-impact case types to prove value quickly; migrate in stages, prioritizing the most valuable or highest-risk workflows first; or start completely fresh without carrying over technical debt from older applications.

Whatever path you decide, one thing’s for sure: it’s going to benefit your organization. However, modernization is a highly complex process with countless pitfalls. As such, it is essential to take advice from experts with intricate Pega knowledge before you begin.

At labb, we are a Specialist Pega Partner with unrivalled insight. Our award-winning team can assess your current platform, model ROI, and design a roadmap that fits your business objectives.