Bottas enters his second year with the Swiss squad for whom he will again race alongside Zhou Guanyu.
The 10-time grand prix winner amassed 49 of the team's 55 points, which saw it end the year tied with Aston Martin but ahead on countback.
While Aston Martin is believed to have made strong progress during the off-season, Bottas is optimistic his team has done the same.
Good early indicators
“Second year, no doubt it's always easier to approach the season because the people know the way the team works,” he explained.
“So it's been smooth preparation.
“Obviously lots of work, as always, but I have no doubt we can do better than last year.
“I think already it was a positive start to the testing,” he added. “Seeing the quality of the car, of the details, everything just seems like a step forward.
“So I've good faith that we can do better than last year. That's the goal.”
Bottas better prepared for F1 testing
Testing went well for Alfa Romeo, although Bottas did stop on track on Saturday after completing a race run.
The team managed to get the C43 repaired, allowing its lead driver to amass just shy of 1000 kilometres of running over the three days – more than 700 of those coming on Saturday.
Zhou suggested the team had made “massive gains” over last year's car after he climbed out of the 2023 machine on Friday evening.
“It's a very different style to last year because last year the testing was a bit of a disaster in terms of reliability,” Bottas said of his time in the car.
“So in that sense positive, but also car balance wise it didn't sound like we were that far off, so a smooth start.
“Still obviously lots of learning to do and it's very early stages.”