Recently, we hosted a Let's talk Constellation webinar with two special guests: @RonaldDeLignie (Principal System Architect at fusionAIx) and @RSIMONIS (Principal System Architect at 1DigitalNL). They shared their in-depth experience and valuable lessons learned from migrating a large, traditional Pega UI application to the Constellation architecture using the Pega SDK.

The project focused on the Instituut Mijnbouwschade Groningen (IMG), a Dutch government institute that processes compensation claims for mining-related damages. The primary driver for the migration was the need to transform their customer-facing self-service portal into a secure, modern application compliant with new security standards.

Key Highlights from the Session

The team's core promise to the customer was to deliver the same functionality, not the same UI. This principle guided their decisions throughout the complex project, which involved migrating over 35 case types for a live application.

Here are some of the key takeaways from their discussion:

• Choosing the Right Architecture (6:46): After analyzing the requirements for a custom-facing portal that needed a tailored user experience, the team chose to build with the Constellation SDK (using React) in a full Portal Mode. This provided the flexibility to implement a custom design system and handle complex user flows, such as users returning to a case multiple times.

• Embracing a "Big Bang" Migration (14:28): While a coexistence or phased approach was considered, the technical complexity led the team to opt for a "Big Bang" go-live. To de-risk this, they ran the traditional and new Constellation applications in parallel during development. Data model changes were merged into a shared base layer and deployed to production early, ensuring they worked with the existing application before the new UI was launched.

• Prioritizing Security from Day One (19.27): Constellation's API-first architecture exposes actions and data more directly than traditional UI. The team performed a thorough security analysis to lock down flow actions, flows, and attachment categories using privileges. They also implemented Attribute-Based Access Control (ABAC) to mask sensitive data, a critical step that couldn't be achieved by simply hiding fields on the UI.

• Harmonizing the User Experience (UX) (23:13): The project presented an opportunity to standardize the look and feel across all 35+ case types, which had previously been developed with slight variations. By working with a UX expert team, they established consistent design patterns, which reduced the number of custom DX components needed and simplified long-term maintenance.

• Data Model is King (27.25): The migration required significant data model adjustments. The team moved away from unsupported constructs like page groups and temporary pages, refactoring them into structured page lists and properties. A key example was converting boolean properties (which can be empty in traditional UI but default to "false" in Constellation) into dropdowns with "Yes/No" text values to ensure a clean user experience.

• A Phased Approach to Development (26:48): To keep the project moving, the team decoupled functionality from styling. DX components were first built to be functional ("staged build") to unblock Pega developers. The final styling was applied later, allowing parallel work streams and focusing initial testing on functionality.

Lessons Learned (37:27)

Ronald and Rogier concluded by sharing their most important lessons from their experience:

The end result for IMG was a secure, modern, and compliant portal with a harmonized user experience. Furthermore, the client's developers and testing community are now trained and ready to build future use cases on Constellation.

Let's talk Constellation series

Enjoyed this? Find more in our Let's talk Constellation series.