At this time last year, the Patriots were parading through Boston celebrating their fifth Super Bowl victory. About 15-20 minutes away, Don Sweeney paraded Claude Julien, the winningest coach in Bruins history, out of town.

There’s no question that Sweeney and the Black and Gold front office endured a public relations disaster with the announcement. A lot was resting on Sweeney’s shoulders with this decision to show Julien the door and promote Bruce Cassidy from assistant to head coach. Given the Bruins position at the time — on the outside looking in of a playoff spot — and a lack of assets and players that could’ve provided the team a spark at the trade deadline, Sweeney had little choice but to pull the plug on Julien and hope Cassidy could navigate the team back into the postseason.

One year later, Cassidy, Sweeney and company survived that PR nightmare and haven’t looked back.

“Yeah, not an easy decision in any way, shape, or form,” Sweeney said about dismissing Julien while the rest of the city was watching the Pats Duckboat route back on Feb. 7, 2017. “In a lot of ways, people would say, well why can’t you just ride out the season…Well, I think the timing became an opportunity for us to evaluate going down the stretch, where these players are and how many of them can fit in to what we want to do going forward and the decisions that we have to make accordingly.”

Sweeney didn’t need any further evaluation after Cassidy guided the team back to the postseason following an 18-8-1 mark during the last 27 regular season games of 2016-17. The third-year Bruins GM removed Cassidy’s interim tag in the days following the team’s six-game first-round series loss to the Ottawa Senators.

Even with a bumpy ride to start the season, Cassidy’s encore performance has been even better.

Whether it’s finding the next man up to replace injured players, getting consistent performances from fellow veterans — most notably Brad Marchand, Patrice Bergeron, Zdeno Chara and Tuukka Rask — or a youth movement led by the likes of Charlie McAvoy, David Pastrnak, Danton Heinen, Jake DeBrusk and Sean Kuraly, Cassidy is pushing the right buttons.

All this has led to the Black and Gold getting points in 20 of their last 21 games and going 26-5-4 in their last 35. Not bad for a team that was written off at certain points under Cassidy, including this their 6-6-4 run through their first 16 games of 2017-18.

Through their highest and lowest points of Cassidy’s tenure, the former Capitals coach sees one constant measure in the Bruins locker room: chemistry.

“I was asked a question a while ago about what came first, the chemistry or the winning? I think it was the chemistry,” Cassidy said following the Bruins 4-1 win over the Maple Leafs Saturday night. “You could see it earlier in the year. It didn’t result automatically in wins, but you could see our guys pulling for one another, [then] when we got healthy and started playing the way we wanted to.”

That B’s victory over the Leafs Saturday in a playoff-like atmosphere at TD Garden snapped a six-game losing streak against their Original Six rivals. A complete opposite result of the early-February meeting last year, which just so happened to be Julien’s last game in his 10-year Boston tenure.

Oh, and that aforementioned 26-5-4 record in the last 35 came after the home and home sweep courtesy of the Leafs in November.

Obviously, there’s a lot more than getting over the Toronto hump that’s led to the success under Cassidy. Aside from the youth movement stealing regular roster spots from the likes of Matt Beleskey and Frank Vatrano, there hasn’t been a whole lot of transition in the Bruins locker room.

It’s all coming together for Cassidy. He has, at his disposal, the top scoring line in the NHL (Marchand, Bergeron and Pastrnak) that accounts for 39 percent of the Bruins offense; a giant 40-year-old presence in Chara who isn’t showing any signs of slowing down in spite of his age; a Calder Trophy candidate in McAvoy; a goaltender that is unbeaten in his last 20 games (Rask); and a balanced scoring depth to go along with three solid defensive units.

“They’re playing with speed, they’re playing fast, they’re not messing around with the puck,” Leafs forward Mitch Marner said, “and I mean when they’re getting their chances, they’re putting them in.”

Come April, the Bruins will be one of 16 teams fighting for Lord Stanley’s Cup. Sure, Sweeney will need to find an upgrade or two by the Feb. 26 Trade Deadline — most notably a second-line winger to play with David Krejci and a left-shot defenseman.

In a year’s time, the Bruins have gone from playoff afterthought to having the fourth-best record in the National Hockey League. And maybe, just maybe, they’ll take another leap forward and hoist the Cup come June and end Boston’s pro sports championship drought, which now stands at 12 months following the Pats loss to the Eagles at the Super Bowl.