As part of the prestigious Belgian "Excellence of Science" research project SECO-ASSIST (see https://secoassist.github.io) we have an open PhD position at the Software Engineering Lab of the University of Mons (Belgium), conveniently located close to Brussels (Belgium) and Lille (France). The goal of the PhD is to explore new recommendation techniques to attract newcomers and retain contributors in software ecosystems, identifying “toxic” team members, predict future abandonment, and find adequate replacements. The PhD will be supervised by Prof. Dr. Tom Mens, head of the Software Engineering Lab of UMONS http://informatique.umons.ac.be/perso/Mens.Tom/ https://scholar.google.com/citations?user=5RJe8dsAAAAJ The position is available immediately for a period of up to 4 years with the aim to obtain a PhD degree. Candidates should be eligible for starting a PhD in Computer Sciences (they should have a Master or Engineering degree or equivalent) and are expected to complete their PhD during the project period. The candidates should have a clear interest in open source software development. Practical programming experience is required, and (practical) knowledge of statistical analysis is a plus. Motivated students that are currently finishing their second year of Master are encouraged to apply. Candidates should send their detailed CV together with a motivation letter expressing their interest in the project by e-mail to Tom Mens (tom.mens(a)umons.ac.be)