I applied online. The process took 2 months. I interviewed at BT Group (Londres, Inglaterra) in Dec 2018
Interview
Firstly there is an SJT which is simple scenerio questions. This is then followed by a video interview which was not very long and tests competency questions. If successful, you're invited to the assessment centre where you have to complete a set of tasks and also have a 1 to 1 interview.
Interview questions [1]
Question 1
Describe a difficult situation you were in and how you overcame it and what you learnt from it.