I am developing a solution where, Fixed BLE beacon detects a moving BLE device and sends the relevant data to the server using wifi/ethernet/etc. All the examples I have found have BLE beacons talking to the mobile phone which in my case isnt true. AFIK an embedded systems engineer can configure the fixed beacon to send data to server. BUT is there any ready to use solution that lets the beacon connect to backend? Thanks.
You mention having a "[f]ixed BLE beacon [detect] a moving BLE device". Understand that this is very different from the way an Apple-style BLE iBeacon works, which is a transmit only device. (I mention this because the question is tagged with ibeacon.)
What you are describing is probably better described as either a beacon scanner or a BLE scanner. My company has a Raspberry Pi-based product that can scan for beacons and take programmatic action based on detections. We have a blog post about how to make a beacon turn on a lamp using this device, but you could just as easily make it contact a server when a BLE device is detected.