Tips are welcome, and the cleaner receives them in full — the company does not take a share.
There are two ways to leave one. You can add the amount to your card payment, and it goes to the cleaner's account together with the settlement for the order. Or you can simply hand cash to the cleaner at the end of the visit, which many clients in Kyiv prefer.
There is no expected percentage, and nobody will be offended if you leave nothing. The cleaner's pay does not depend on tips: it is a fixed share of the order value, so a tip really is a bonus rather than part of the wage.
If you want to say thank you in a way that lasts longer, a public review with the cleaner's name matters more. Ratings determine how many bookings a person receives, and requesting the same cleaner for your next visit is the strongest signal of all — such repeat orders are also paid at a higher rate.