Most European airlines open pilot selection with an online cognitive assessment, and a large share of them use one publisher: Aon (formerly cut-e). Expect a battery of short, tightly timed tests — numerical and verbal reasoning, working memory, multitasking, concentration and often a situational judgement test. The question formats are identical across airlines; only the mix and norm groups differ.
Note: not every airline uses Aon — Lufthansa/Austrian test via DLR, Eurowings/Condor via Interpersonal, Wizz Air and Brussels Airlines via COMPASS, TUI via Sova. Your invitation names the provider.