The 36-3 win - featuring tries from Jonathan Spratt, Sam Parry, Josh Matavesi, man-of-the-match Justin Tipuric and an Eli Walker double - moved the Ospreys up to eighth in the table.
And, for Tandy, the key now is to find some continuity in order to maintain that climb.
"We are starting to get the group back together now - some boys have been away for four or five months - and now we are starting to get a little bit of consistency with everyone back in training," he said.
"The one thing I love about the group is that we don't doubt ourselves. We're a little bit short in some things but it isn't going to be for a lack of effort.
"It's a group that you can't wait to come to work and train, and those boys are responding. They aren't frightened of the fight to try and climb the ladder in this competition."
The Ospreys have no doubt been helped by the return of their Rugby World Cup stars, with Tipuric, Alun Wyn Jones and Dan Biggar all impressing against Zebre.
And while Tandy is still missing injured scrum-half Rhys Webb - last season's GUINNESS PRO12 player of the year - he is confident that Brendon Leonard, Tom Habberfield and Martin Roberts have ample talent to fill the No.9 shirt.
He added: "Obviously it is disappointing to lose Webby, potentially until February, but the three nines we have got in training at the moment - that is one area that we have got strength in depth and all three are delivering in training constantly."
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