A Tech Radar is a list of technologies, complemented by an assessment result, called ring assignment. We use four rings and four quadrants with the following semantics:
The Adopt ring represents blips that we think you should seriously consider using. We don’t say that you should use these for every project; any tool should only be used in an appropriate context. However we do think that a blip in the Adopt ring represents something where there’s no doubt that it’s proven and mature for use.
The Trial ring is for blips that we think are ready for use, but not as completely proven as those in the Adopt ring. So for most projects we think you should use these on a trial basis, to decide whether they should be part of your toolkit.
The Assess ring are things to look at closely, but not necessarily trial yet - unless you think they would be a particularly good fit for you. Typically, blips in the Assess ring are things that we think are interesting and worth keeping an eye on.
The Hold ring is for things that, even though they are accepted in the industry, we haven’t had a good experience with. Therefore we are calling them out to warn you that you may run into trouble with them as well. Sometimes this is because we don’t think they’re mature enough yet; sometimes it means we think they’re irredeemably flawed; or just being misused. We do place things in the Hold ring that we wish the projects wouldn’t use.
Databases, messaging systems, data managements tools and any data centric components.
Things that we build software on top of such as mobile technologies like Kubernetes, Clouds, virtual platforms (Android, JVM) and other tools used for the infrastructure.
Software development process, design patterns and techniques for structuring software.
Programming languages, frameworks, libraries and related components.
The Tech Radar is a tool to inspire and support developers to pick the best technologies for new projects; it provides a platform to share knowledge and experience in technologies, to reflect on technology decisions and continuously evolve our technology landscape. Based on the pioneering work of ThoughtWorks and the open source project of Zalando, our 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 use in their projects.
The Tech Radar is maintained by a group of architects who faciliate and drive the technology selection and discussion across the company. Assignment of technologies to rings is the outcome of ring change proposals, which are discussed and voted on. The Tech Radar is open for contribution for all developers and depends on their active participation to share lessons learned, pitfalls, and contribute to good practices on using the technologies.