Geoffrey De Smet | Devoxx

Devoxx Belgium 2018
from Monday 12 November to Friday 16 November 2018.

Geoffrey De Smet is the founder and lead of OptaPlanner (, the open source A.I. constraint solver in Java that is used across the globe to automatically solve employee rostering, vehicle routing, task assignment, maintenance scheduling and other planning problems.

See also

The battle of 2 automated conference talk scheduling algorithms for Devoxx


Each conference talk has a timeslot and room. These aren’t assigned randomly. Ideally, a rock star speaker gets a big room. And if a speaker is still flying in on the first day, his/her talk must be on a later day. An introductory session should be before the advanced session on the same topic. These are all constraints. And there are many more of them. Some are soft (we can break them), but others - for example a speaker cannot have 2 talks at the same time - are hard, because no person can be in 2 places at the same time under the laws of this universe.

As you can image, scheduling those talks optimally is hard. So let’s automate it. Two separate projects use advanced A.I. algorithms to tackle this problem for Devoxx Belgium.

In one corner we have OptaPlanner, the general purpose open source constraint solver in Java, lead by Geoffrey. In the other corner we have NoConf, a dedicated algorithm in Scala, lead by Piotr and Viktor. Which one delivered the best result according to Stephan Janssen?

Let’s get ready to rumble!

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