The wifi works well for working purposes - video meetings etc. The host were really great with communication and the location is good with restaurants, grocery shopping and access to public transportation nearby.
There are no windows in the living room so it felt crammed at times. The main door is directly to a busy street so we couldn't open the blinds in the door because people would be able to view directly at us. You could hear most things happening on the street because the main entrance was a glas door with metal grids. There's a convenience store next to the flat and people were hanging out, sitting on the doorstep and drinking beer most of the day.
There's a backyard from the living room, however, since it's a silo without any views, it felt like sitting in a back alley so we didn't use it at all.
The kitchen was well functioning.
Would recommend for short stays and if the main purpose is to explore Lisbon. It wasn't ideal for remote working because of the lack of getting fresh air throughout the day.