As Israeli drones buzz overhead and ambulance sirens wail in the distance, Tarik Zaeem stays hunched over his laptop, working through lines of code for a Saudi valet parking app, debugging its barcode reader.

Nickolay Mladenov, who is overseeing the U.S.-led truce in Gaza, has tried to convince the militant group to give up its arms, but it has so far refused amid Israeli cease-fire violations.