I have been working in networking for over a decade but I am a newbie in IoT domain.
I wanted to know if someone can advise how to find wifi throughput on photon 2.
For an outdoor wifi mesh solution I was thinking to use p2 as a probe but I am unsure if it is capable of running such code due to limited memory? If so, what is the theoretical throughput that it can achieve on 2.4GHz and 5GHz.
I wouldn't try to use a Photon 2 for measuring Wi-Fi throughput. The Wi-Fi interface is intended for low-volume IoT traffic and won't come anywhere close to measuring the maximum throughput of a Wi-Fi network. Something like a Raspberry Pi would probably be a better choice.
Measuring signal strength would work well. The WiFi.scan() function finds all nearby APs and returns the SSID, MAC, RSSI (signal strength), and channel. That should be all you need.