If you were improving a system, how would you pick a KPI? Can you give me an example of a KPI you would keep an eye on, at Adyen?

Free for the first 3 answer contributors

Interview question asked to Technical Program Managers interviewing at Adyen: If you were improving a system, how would you pick a KPI? Can you give me an example of a KPI you would keep an eye on, at Adyen?.