German insurance company HDI achieves a 50% reduction in lines of code by migrating to Vaadin

Lilli Salo
Lilli Salo
On Jun 21, 2022 5:11:25 PM

HDI is in the process of modernizing its business-critical application, Policy. The company migrated the internal application’s client side, originally built on RCP and SWT, to Vaadin Flow V14 to make use of our comprehensive selection of web components. Read the full story below.

The company: A global insurance partner for handling business risks

With its headquarters in Germany, HDI is a global insurance partner for companies operating in a range of sectors, from manufacturing and service industries to commercial. HDI helps its customers handle business risks by offering innovative, needs-based insurance solutions.

HDI uses an internal application called Policy, built in 2009, for the end-to-end management and editing of complex contracts and for creating policy documents and invoices for the company’s corporate clients. 

However, the original application was significantly slowing down development processes, and HDI needed to find a new Java-only solution to meet the standards of a modern business app that is also equipped for the cloud. 


The project: Modernizing a complex, business-critical application

HDI’s Policy application boasts a complicated, three-tier architecture with its entire business logic in the backend, and an Eclipse RCP (SWT) client that uses 420,000 lines of code to manage the application’s UI. 

By modernizing Policy with Vaadin, HDI was looking for faster delivery of development updates for the business-critical application. With the old RCP, changes could only be deployed every two months, which drastically reduced the productivity of HDI’s development team. If the developers found a bug in the UI, it was not possible to deploy any fixes or changes on demand. This was one of the biggest drivers for modernizing the application and rewriting the previous RCP client into a Vaadin client with a Spring Boot backend. 

Why Vaadin?

Vaadin felt like a natural choice for the development team at HDI for several reasons:

  • Continuing development in pure Java. HDI wanted to continue developing Policy in pure Java, because the team consisted of only Java developers without prior experience in web development. Therefore, frameworks based on TypeScript or JavaScript were phased out early on. 

Moreover, by continuing the app development in pure Java, HDI were able to reuse all of their current business objects, data containers, and so on. To provide further new functionalities, the old Java code was refactored and upgraded to Java 8.

  • Faster development speed with Vaadin. Another compelling reason that HDI opted for Vaadin was the incredible development speed it offers. Vaadin Flow’s structure and architecture are similar to that of SWT, so developers required very little training before the modernization project and could jump directly into the transformation of the application’s client side.
  • A comprehensive library of web components. Vaadin offered all the necessary components needed to complete the modernization of the UI. Each field was configured with CSS, so that any styling, such as font size, could be applied quickly. In addition, particular attention was paid to accessibility by using braille-friendly numbers in the fields.

During the entire process of modernizing Policy, the old RCP application is run side-by-side with the new one until the Vaadin client is stable. Altogether, HDI plans to transform over 350 app views and 250 dialogs into the new Vaadin client. The performance of the system is already much better than with the RCP.

The result: From 450,000 lines of code down to 250,000

The modernization of Policy is an important step in HDI’s digital transformation strategy, and Vaadin is the key to preparing the entire application for the cloud environment. The Vaadin client is a new approach which HDI delivers in their cloud platform, solving the problem of fast delivery. 

Thanks to the modernization, the development team at HDI are able to deliver a new version of the Policy application to their clients every two weeks. Any defects found in production can be fixed promptly, without the need to wait two months to deploy the changes.

Having started in October 2020, the entire Vaadin transformation is expected to be completed by summer 2023. To date, the team at HDI have made tremendous progress in migrating Policy to Vaadin and have drastically reduced the amount of code they must use and maintain. All in all, HDI simplified its application from 450,000 lines of code down to 250,000 – almost a 50% reduction in code!

The new Vaadin client side has been well received by its users. In particular, they have been very impressed with the modern UI, but also surprised by how quickly changes can be implemented.

In addition, the Vaadin platform received lots of compliments from the HDI team as a complete solution for developing expert business systems that require complex views with many fields. Furthermore, Vaadin helped their team deliver the migration project by answering any questions the team had through Expert Chat. As a result of getting answers quickly, their team were able to maintain high levels of productivity and focus on their work:

The support from your side, [Vaadin], was incredible. I liked it! Or, I would say I love it! If I have a question, I receive an answer in two minutes. That’s not even enough time to grab a coffee!

- Tino Reichardt, HDI

Figure 1: View for editing a contract

Figure 2: View for editing a specific insured item

Looking to remove technical debt and future-proof your business application through modernization? Reach out to our team of experts, and we’ll help crystallize a path forward for your app!

Lilli Salo
Lilli Salo
Lilli joined Vaadin in 2021 after delivering content for various international SaaS startups. She enjoys the creative challenge of transforming complicated topics into clear and concise written material that provide value to the reader.
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