Is it safe to carry cash, and how do people handle large payments?

Use everyday street smarts: carry only what you need, withdraw from ATMs inside banks or malls (not on the street), and keep your phone discreet. For big cash payments like rent, ask the landlord if they accept a bank/Nequi transfer (many do once asked), or withdraw at a bank during business hours. "No dar papaya" — don't flash valuables — is the local rule of thumb.