I'm doing backend development but interact with frontend developers all the time. Something I've noticed, especially among younger devs, is that they are sometimes unknowledgeable about how HTTP, DNS, certificates, and related tech work, and have a hard time grasping why state persistence and synchronization need to be done a certain way. The problems arise when something goes wrong and they immediately need support from backend, when a little more knowledge about the technologies below React or Angular would suffice.