Soon after I applied online I received a phone call from Deliveroo. They asked a few basic questions about my bike, ability to work in the Uk and my cycling ability. Then they arranged for me to have a trial session.
For the trail session I had to meet a Bike Courier in town. I arrived at the specified time, but it took 15 minutes before a Bike Courier arrived. The Courier then said he didn't know who was conducting my trial session. After making a phone call he decided to do it himself. The trial session involved following him while he did a few deliveries. The guy darted rather quickly though pedestrians on a footpath, in a very busy part of town, in a very dangerous manner. As such I trailed behind him slightly. I asked him afterwards whether it was okay for him to be driving in that manner on footpaths. He replied that it was probably not okay, but in order to make deliveries in time he had to. He said they have a very quick turnover of cyclists, and if you don't make deliveries quick enough they let you go.
In the end he said he didn't want to progress me as he didn't like the location of the gears on my bike. I have a road bike where the gears are located on the frame of the bike instead of the handle bars. This was definitely just an excuse though, as I have since seen several Deliveroo couriers with single gear bikes.
The interviewer said he was quitting soon anyway. So I was under the impression he didn't really care much. In all honesty I think he did me a favor.