The employee never pays out of pocke. Note it's not a loan, but an investment.
Upon a liquidity event, the employee needs to pay back the investment amount + certain percentage of their shares. If the total amount is lower than the investment amount, the payback amount is capped by the amount they received for their shares. Thus, the employee will never pay out of pocket.
Regarding the share %, that varies based on the demand by the investor community for the specific company, and the specific employee strike price.
Upon a liquidity event, the employee needs to pay back the investment amount + certain percentage of their shares. If the total amount is lower than the investment amount, the payback amount is capped by the amount they received for their shares. Thus, the employee will never pay out of pocket.
Regarding the share %, that varies based on the demand by the investor community for the specific company, and the specific employee strike price.