Half year ago, we agreed on a set of principles and started working on our Tech Radar; now, we’re proud of having published its second release for Zalando Technology. We’ve also open sourced the Zalando Tech Radar visualisation (including code) via ourpublic GitHub repository.

Some of the more prominent changes compared with first Radar release are:

• Play for Scala and Sbt moved from Trial to Adopt
• Kafka also moved from Trial to Adopt
• Flink changed from Assess to Trial
• AngularJS 2.x rises to Assess, whereas AngularJS 1.x descends from Adopt to Hold

Why did we create the Tech Radar?

The Zalando Tech Radar was created to inspire and support teams to pick the best technologies for new projects. It provides a platform for Zalando to share knowledge and experience in technologies, to reflect on decisions, and continuously evolve our landscape.

Based on the ideas of ThoughtWorks, Zalando’s Tech Radar sets out the changes in technologies that are interesting in software development; changes that we think our engineering teams should pay attention to and consider using in their projects.

What is the Tech Radar?

The Zalando Tech Radar is a list of technologies, frameworks, tools, and methods complemented by an assessment result called a Ring assignment. We use four rings with slightly adapted semantics to fit our purpose:

• Adopt: Technologies we have high confidence in to serve our purpose, also in large scale. Technologies with a usage culture in our Zalando production environment, low risk, and recommend to be widely used.
• Trial: Technologies that we have seen work with success in project work to solve a real problem; here we have the first serious usage experience that confirm benefits and can uncover limitations. Trial technologies are slightly more risky; some engineers in our organization have gone this path and will share knowledge and experiences.
• Assess: Technologies that are promising and have clear potential as well as a value for us; technologies worth investing some research in and prototyping efforts to see if it has impact. Assess technologies have higher risks; they are often brand new and, while promising, highly unproven in our organisation. You will find some engineers that have knowledge on the technology and promote it. You may even find teams that have already started a serious prototyping project.
• Hold: Technologies not favoured to be used for new projects. Technologies that we think are not (yet) worth (further) investing in. Hold technologies should not be used for new projects, but can usually be continued for existing projects

The Tech Radar is created by the Zalando Technologist Guild – an open group of approximately 25 Zalando senior technologists. The Guild self-organises to maintain Tech Radar documentation, including the quarterly Zalando Tech Radar Release and its visualisation published via GitHub. The ring assignments represent the average votes of the Guild’s members; our voting is based on preliminary discussions within the Guild to achieve (more or less) high consensus.

How does it work?

The Zalando Technologist Guild maintains the Tech Radar and Compendium, as well as provindig a forum for conversations, knowledge sharing, and supporting the engineering teams with peer review feedback on their technology selections.

Guild members meet monthly to discuss the updates of the Tech Radar assessments, and upcoming and ongoing issues around technologies and architectural decisions.

Together with the Tech Radar we also maintain the Tech Radar Compendium — a collection of summaries of listed technologies including a short description of what they are, why they’re used, and risks of use. This is supplemented with information about what teams internally at Zalando have used these technologies to solve a certain problem. It continuously grows with any Tech Radar changes and will hopefully evolve into a valuable resource for us to share information and get teams connected.

The Zalando Tech Radar Principles work hand in hand with Zalando engineering team contributions. Our Rules of Play include obligations for our Engineering teams: Teams must use the Tech Radar as one input source for their technology decisions. Teams are encouraged to challenge the Tech Radar and provide feedback to the Technologist Guild.

Depending on the current assessment status of the technology candidate, teams should align decisions with their Delivery Leads, inform or ask the Technologist Guild for peer review feedback on the purpose and risks, and share their knowledge and experience with other teams and the Guild.

Teams contribute to move technologies onto radar rings by giving feedback, informing about an analysis, or prototyping activity whilst sharing experience and results with the Guild and other tech parties.

If you want more information about the Technologists Guild or the Zalando Tech Radar, get in touch with me on Twitter @ThFrauenstein.