What practical issues arise when deploying WiFi (or 2.4 GHz wireless) on embedded devices?

Several recur. Provisioning headless devices: a device with no screen or keyboard still needs the WiFi SSID and password, so you need a setup flow, commonly a temporary BLE or SoftAP (the device hosts its own access point) mode that a phone connects to, enters credentials, and the device then joins the real network; this must be designed in early and secured so credentials aren't sniffed. Power and reconnect cost, as discussed, duty-cycling helps but association/DHCP/TLS setup costs energy each wake. 2.4 GHz coexistence: WiFi (on 2.4 GHz), BLE, Zigbee, and microwaves all share the band, so congestion causes retransmissions, latency, and extra power; combo chips arbitrate BLE/WiFi internally, and you may need channel planning, and RF layout/antenna design and matching strongly affect range and reliability. Security configuration: WPA2/3 must be set up correctly and credentials stored safely; BLE pairing/bonding modes must be chosen to actually authenticate and encrypt rather than shipping "just works" open. Network realities: handling DHCP lease renewal, captive portals, AP roaming, and graceful reconnection after the link drops. And certificate/time management if using TLS (the device needs correct time and trust anchors). So embedded wireless is less about the happy-path connect and more about provisioning, power-aware reconnection, RF coexistence and layout, and security, the operational concerns that determine whether the product works reliably in the field.