Gioni Mexi, Deborah Hendrych, Sébastien Designolle, Mathieu Besançon, and Sebastian Pokutta were awarded the Land-Doig Competition Prize 2025 at the Mixed-Integer Programming Workshop 2025 for the best contribution to the heuristic solution of Mixed-Integer Quadratic Optimization Problems (MIQP and MIQCQP).
The competition focused on the development of innovative primal heuristics that can quickly generate high-quality feasible solutions. The awarded contribution extended Boscia.jl – developed at the Zuse Institute Berlin – with novel Frank-Wolfe-based large neighborhood search heuristics, as well as gradient- and decomposition-based heuristics, specifically designed for quadratic optimization problems.
The method found feasible solutions for 88 out of 95 benchmark instances, on average in just 12.8 seconds, and achieved a mean optimality gap of 5.1%. In addition, it improved eight best-known solutions in the QPLIB benchmark library.
The photo shows, from left to right: Jan Kronqvist, Assistant Professor at KTH Royal Institute of Technology in Stockholm and member of the competition’s organizing team, and Gioni Mexi.