Alonso made headlines when he produced a tenacious drive in the Hungarian Grand Prix, crucially holding off Mercedes' Lewis Hamilton for several laps while teammate Esteban Ocon secured his maiden victory.
But Budapest wasn't the first time 40-year-old Alonso left his Enstone team stunned by his race craft and his ability to read races from the cockpit, the double world champion often being aware of the full picture as much as his team on the pitwall.
"I've worked with a number of drivers a bit more than 20 years in F1 and he is extremely impressive," Budkowski said. "He's impressive in his approach, which is very, very professional.
"The other thing that blows me away is his race craft. And I think we've seen it in the [Silverstone] sprint race, we've seen it in Baku, they were great opportunities to see that.
"What Fernando did in Silverstone was effectively forming a DRS train behind him, because he wasn't afraid of [Lance] Stroll but he was afraid of [Pierre] Gasly and therefore he eliminated any possible attack from Gasly by putting him in Stroll's DRS.
"For me it's mind blowing almost because we're sat on the pit wall, we have all the data, we have full visibility on the race.
"He is in the car driving at full speed and he has almost the same analysis of the race that we have on the pit wall with nowhere near as much data and an ability to take a step back.
"That's I think the thing that impresses me the most in Fernando. I guess it's 20 years of experience driving Formula 1 cars but not many drivers, even with 20 years experience, will be capable of that."
Alonso claimed that his two decades of experience in F1 has only made him a better driver, suggesting he would now beat his 23-year-old self "with one hand".
Budkowski has also noticed Alonso is still as hungry and ambitious as ever, and believes the Spaniard will remain in F1 for years to come if Alpine manages to give him a fast car.
"How long [he'll go on], it's a question for Fernando, [but] he doesn't feel like an old man ready to retire," Budkowski explained.
"He's hungry, he's looking forward to next year. Every time he's in a factory he's asking how's next year car coming along.
"You can see that he's enjoying it, he's happy to be back in Formula 1 but obviously he's ambitious, like our ambition is to do better than we're doing now. That's what we're working hard on for next year and he's excited about that.
"If we give him a competitive car next year, I don't think he's going to go anywhere anytime soon, because he's going to want more and more of it."