Over the last two decades World Wide Web has become a new branch of industry. As such it is a subject of engineering in designing, building, maintaining and improving various web services and their components. However, it is hard to refrain from observing that some components of the web are constructed in an ad-hoc way. Web engineering should not be exempted from the analysis and optimization of its processes. Hence, web engineering should profit from many decades of OR experience. And vice versa, the OR society should not omit this new and emerging field of applications.

The stream on Operations Research and Combinatorial Optimization in Web Engineering at Euro 2016 conference, to be held on July 3-6, 2016 in Poznań, Poland, is intended to bring together OR/CO researchers and Web engineers to share their experience for a common benefit. We understand "web engineering" very broadly, so all studies on web operations and optimization are welcome.