Our flight was TAP Air Portugal from Manchester, and arrived on time at 2pm. We were bussed to the terminal, and the arrivals area was COMPLETELY EMPTY APART FROM OUR FLIGHT.
There were around 20 machines that you go to, and some of them didn't work properly, or took several attempts, so I can see that if you arrive along with other international flights the queue would build VERY quickly. You scan your passport, then have a face photo, then fingerprints. Then it asks if you have completed the Travel Europe app, which we had, and you scan the QR code on the app, and it tells you 'proceed to e-gates'. (I assume that if you haven't done the app you would just answer the same questions on screen.)
My husband's worked first time, but mine had a problem - I had to do the photo twice because I wasn't fast enough taking my glasses off so I wasn't facing the camera. (I have to keep my glasses on until that point otherwise I can't read the instructions on the screen 😂) And then after the fingerprints it didn't ask me for the app but told me to go to the manned passport check. We walked across to the place where you separate according to which lane you're using, and there was an attendant advising people which way to go. (He was the ONLY staff member there in that area, which was fine for us, but would be totally inadequate for hundreds of people arriving at once.) He said if we wanted to stay together I could just try again at the machine and it might work. As there was still no queue, I did that, and it worked perfectly, so we both headed for the e-gates.
To go through them you scan your passport to go through one gate, then stand still while it takes your photo, then the second gate opens and you're through. Except I got caught out taking my glasses off again (it doesn't wait till you're ready!) and the screen just stuck on 'please wait', and never changed. So I was now stuck in the little space between the 2 gates, no way to get back out of the first one, and there was no-one around to ask what to do! Eventually my husband managed to get the attention of a staff member at one of the nearby gates. She came over, and said 'I think you just have to keep waiting', but after a while longer she asked for my passport so she could scan it again at the entrance. This didn't seem to make any difference, but after several more minutes the screen did eventually clear, and I was able to take the photo and get through.
Even with those delays it was literally only 15 minutes until we were out the other side. The only downside for us was that we had pushed our car hire booking back to 4pm instead of 3, anticipating long delays, and had one and a half hours to wait! But I'd rather that than the alternative, and we just had a nice coffee and snack while waiting.
So the moral is - be lucky with timing (I don't think there's really a way of controlling or anticipating how busy it will be when you arrive, but others might know how to figure that out?) And if you wear glasses be prepared to whip them off quick and face the camera 😂