This is partially extracted from our internal Open Source Training documentation.

When does Zalando own your work?

For the legal definition, have a look into your employment contract, but it usually says something like this.

In any of the following three (often overlapping) cases, works created by employees (or rather, exclusive copyright on them) are owned by the employer:

The work is in connection with business-activities

The work is part of fulfilling your job role. It might not be a direct output of your role, but also work which was needed to be able to get your daily tasks done.

The work is part of an agreed upon assignment at Zalando

Your lead told you to create this, you might have worked on it in your personal time, but it is still the property of Zalando as it is a work assignment.

The work is done with Zalando resources or materials

You spend time during work hours, you used servers or cloud services paid for by Zalando, used Zalando data or other Zalando intellectual property or used other company resources such as marketing or sales.

When does Zalando not own your work?

If you work on your own time, on your own computer (and using also no other Zalando resources), on a non-Zalando-related project, Zalando generally has no rights on your creations.

Avoid grey areas, where the ownership is not clear.

(your personal project)

The project is your property. If you get contributions from others, those are property of the contributors, though usually you should require them to at least license them to you.

(a project of someone else)

The project is property of its owner. Your contribution is your property (but generally at least licensed to the project (and other users) under some license, and often a CLA requires you to assign copyright to the owner).

(a Zalando project)

The project is property of Zalando. Your contribution is your property, but licensed to Zalando (and all other users) under MIT License.