The Spaniard finished fifth in the drivers' championship with four podiums over the course of 22 races, besting team-mate Charles Leclerc in the final reckoning.
Sainz proved quick out of the gates as the season opened, seemingly adapting to the SF21 with comparative ease – certainly when compared to other drivers who switched teams such as Sebastian Vettel and Daniel Ricciardo.
Looking back on the year, the 27-year-old was left pleased with his performance.
“It definitely gives me satisfaction to finish the year stronger than I started,” Sainz said.
“I think I always managed to start the year on a very good level, which was the biggest challenge, learning a new car.
“Then I had a lot of things to improve on my driving, on the starts, on the race management,” he added.
“I would say this last third of the season I've been the Carlos that I wanted to be, and the Carlos of the two very strong years in McLaren.
“This has given me the opportunity to be very good in qualifying again and good in the races, and consistent.”
Sainz ended the year with 164.5 points to his name while Leclerc, in his third season with the Scuderia, scored 159.
“More symbolic more than anything,” Sainz said when it was put to him that he'd finished ahead of Leclerc in the title race.
“But it's yet another strong sign that this year was strong, that this year was positive for me, especially a way it finished in this last third just gives me a lot of confidence going into 2022.
“Whatever happens, and whatever car Ferrari and I have, we will go for it because my confidence is high.”