Kubica, who has one grand prix win to his name, convinced Williams to give him a race seat alongside F2 Champions George Russell after the work he has done as reserve driver this year.
“One of the things that impresses me most about Robert is the fact we didn’t give him the race seat for this year, yet he still took on the role of reserve driver and I think that says a lot about his personality,” deputy team principal Claire Williams said.
“The very fact he has had the time he has had this year, working with the team behind the scenes, has given him invaluable experience to step up into that race seat for next year.
“He knows everybody in the team, he gets on well with everyone in the team, he is dedicated, he spends a lot of time back in the factory in order to help drive our performance.
“Now he’s absolute ready. We undertook that evaluation process and he came out on top of the pile, and for us next year, it was always a question of making sure we secured the best talent rather than any other factors.”
Kubica made a number of outings in FP1 during the season, as he continues to make his way back to the top after a horrifying crash back in 2010.
The Pole sustained severe aim injuries in a rally crash, which interrupted his promising racing career.
After eight years out of the sport, Kubica will return, having helped Williams develop the FW41, and next year’s contender, the FW42.
“We have done a thorough analysis into what’s gone wrong this year,” Williams explained.
“Robert has played an instrumental part into the development of the FW41 and he is going to be a big part of helping us develop the FW42 and beyond that.
“He has an extraordinary understanding of engineering and is a real pusher as well, he helps drive the engineers in what they’re doing and he pushes me.
“He talks to me at 2AM in airport lounges around the world around what has gone wrong, what we need to be doing.”
The man himself acknowledged how important the development role was, adding that it provided him with a opportunity to get embedded into the team.
“Many people see it as a kind of loss from my side but I don’t see it like that,” Kubica said.
“I see it as a very useful year for myself, with having the opportunity to work with the team and the opportunity to drive the car.
“Everyone remembers me from the old days but when I joined last year at the team and when I came here for the test it was only the second time I had driven a new generation of F1 cars.
“This gave me the opportunity to understand a bit more about the car from a technical point of view and gave me the opportunity to understand it from a different perspective about how the team works when you are a race driver as you are focused on your job.
“I have been an active part of the team this year, I haven’t been racing, so it gave me a lot of time to see different things.
“I think it was very useful, maybe not from a driving perspective, but from a teamwork perspective, how to do it, how it works and what we can do better.”