Some data sample analysis done during interview

Installation

Make sure you have java 1.8 JRE and JDK installed
Navigate into project root directory
Run ./activator 'run [data file] uid1 uid2'

Definition of "meeting"

I'm assuming that both persons were within a distance of 3 meters in 1 minute time frame

Bonuses

Detecting time and location of meet
No external database
Use of functional language
Modular and testable components

Things I could improve

Remove noise, maybe some clustering algorithm
Add grouping by floors, and run the search in parallel on each floor