Ask whether the Zielbonus is individual, team, or company-wide, and what percentage of target was paid in each of the last two years for your role family.
Clarify the payout calendar. Some plans settle in March for the prior year; others withhold until you clear probation.
Commission roles need territory definitions, clawbacks, and what happens when accounts move. Get those in writing, not only in a deck.
If equity or virtual shares appear, note vesting, leaver clauses, and whether the plan is a formal Mitarbeiterbeteiligung or an informal promise.
For negotiation, convert variable components into a conservative expected value. Argue from that number, then decide how much risk you accept in exchange for upside.