Preface Anthony Nixon and Sean Prendiville; 1. Fair partitions Noga Alon; 2. Hypergraph Turán Problems in \ell_2-norm József Balogh, Felix Christian Clemen and Bernard Lidický; 3. Circuit imbalance measures and linear programming Farbod Ekbatani, Bento Natura and László A. Végh; 4. Intersection problems in extremal combinatorics: theorems, techniques and questions old and new David Ellis; 5. Finite geometry and extremal graph theory Valentina Pepe; 6. Rainbow subgraphs and their applications Alexey Pokrovskiy; 7. Explicit bounds for graph minors Paul Wollan; 8. Convex and combinatorial tropical geometry Josephine Yu.