To attain the dream of owning a home, people require a solid, affordable mortgage. For the average person, however, it is practically impossible to compare multiple offers from banks and find the right one – too many individual and market criteria have to be taken into account. For more than 20 years, the Interhyp Group has been helping people who want to build or buy homes. Interhyp’s financial experts compare more than 500 lenders for their customers and develop customized mortgage solutions. With more than 1,700 employees in over 100 locations, today Interhyp is the largest broker of residential mortgages in Germany.


For their daily work, Interhyp advisors use a central mortgage platform. When a customer comes into a regional office or makes contact online, the advisor first tries to understand the customer and the desired property as precisely as possible – from the location and type of the desired property to the targeted loan amount and equity ratio to the possible payment terms. In addition to manual data entry, many documents are scanned, classified, and stored. The platform then compares the customer’s preferences with the banks’ offers and finds potential financing partners. Interhyp advisors evaluate the results and give the customer concrete recommendations. Outlooks on future, probable market developments, such as interest rates, round out the recommendation and provide the customer with all the necessary details for making an informed decision.

The web platform, which is predominantly based on Java and JavaScript, includes a large number of services that interact with one another on the backend. These Java- based microservices integrate with Python-based tools that provide other necessary services, such as document classification and interest rate estimates.

“The large number of applications and the different languages, runtimes, development kits, and language libraries are always a challenge for IT management,” says Willi Bühler, Head of Application Technology at Interhyp. “In addition, as a financial service provider, we operate in an industry that is subject to strict compliance and risk management requirements. At the same time, we are required to weave compliance into our development process. We achieve this with automation and state-of- the-art technologies.”

Change Management with Special Challenges

As a result of these requirements, Interhyp’s IT infrastructure must always comply with very specific security specifications. It is not enough to set up the systems and applications once in compliance. Every change, both in software and hardware, must be documented precisely and clearly. All necessary information must be recorded in change records, such as what changes were made, which applications are directly and indirectly affected, who made the changes, and what the release process looked like.

“My team looks after several hundred services, and without automation tools it wouldn’t work at all,” Bühler says. “We have been automating the change processes themselves, i.e. the configuration of servers and services, with Open Source Puppet (OSP) for years. For our internal IT service management processes, we also use ServiceNow. Both are very powerful tools – but they were no longer sufficient, on their own, to meet the requirements for compliance documentation.”

Open Source Puppet ensured that all changes made by developers and administrators were rolled out automatically to all servers. Although this made the work of the Interhyp team much easier, Open Source Puppet was no longer the optimal solution for the growing number of change processes and their documentation. Change records had to be written – not feasible when 20 to 30 changes are to be implemented per day and each takes about 15 minutes to fill out a corresponding form.

“The solution was actually obvious,” says Bühler. “Since Puppet knows what it changes, we only needed to connect it to ServiceNow, our IT service management tool, and add functions for documentation. So we approached Puppet and got top-notch support from Puppet professional services.”

“With our then-current configuration management tool, if I had to make a change across 5,000 VMs, and 2000 of them were deallocated and offline, I would then need to automate the starting of those VMs,” explained Kelly Evanson, infrastructure manager at Finastra. “Then I would need to go in, apply the change, and it would need to be deallocated again. It just becomes an unmanageable process at scale.”


The team at Interhyp elected to move to Puppet Enterprise and adopted Continuous Delivery for Puppet Enterprise (CD4PE), an additional tool that supports continuous delivery of code, integrates with ServiceNow, and analyzes changes and checks the impact on other systems. The CD4PE pipeline can be customized to define verification steps and incorporate necessary approval processes. Based on these factors, Continuous Delivery for Puppet Enterprise evaluates the changes and passes the corresponding information to ServiceNow. A change record can now be created automatically in ServiceNow – with all the information required to meet compliance and risk management requirements. This solution is ideal for meeting the needs of Interhyp.

The switch from Open Source Puppet to Puppet Enterprise was straightforward. With manageable adjustments to the code of the existing installation and the configuration of a few new systems, the migration was completed in just two weeks. Continuous Delivery for Puppet Enterprise was then installed, and the Interhyp-specific workflows were defined and enabled. After only four weeks of the project, it was already easier to answer all questions about changes. With just a few clicks, all change details can be viewed.


“With Puppet Enterprise, Interhyp has managed to automate change management for our Linux-based infrastructure, and in such a way that all documentation requirements are now also fulfilled without any additional time spent, as dictated by compliance and our own audit processes,” says Bühler. “We simply no longer have to worry about whether all the necessary information is included in the change record. We can rely one hundred percent on our automation processes.”

Strict compliance requirements are a critical foundation for Interhyp’s business. Interhyp’s digitization strategy keeps that foundation strong and secure with the help of Puppet Enterprise automating as many processes as possible. With Puppet, Interhyp has a supportive partner at its side.


See for yourself what Puppet Enterprise can do for you.