Friday evening, thousands of city residents and college students will flood Boston City Hall Plaza as folk singer Gregory Alan Isakov kicks off the performances of this fall’s edition of Boston Calling, the city’s premier music festival. The festival’s organizers, however, won’t be as quick to celebrate.

“No high fives until the last piece of equipment leaves the plaza,” said Mike Snow, co-founder and producer of Boston Calling.

Construction started on the festival earlier this week, and the venue will be used for two and a half days — from Friday afternoon to Sunday night. After the performances are over, everything will come down in under 36 hours.

“It’s a killer,” Snow said. “It’s a lot of work, but everybody here is sort of really passionate about it, so it always pays off.”

Though the construction process only takes a few days, Snow said that the line-up selection and curating process started about seven or eight months ago and, with all the touring schedules to juggle, took approximately four to five months to complete.

“When you really think about it, a band is a whole moving city and a whole moving business, and to get it so that business locks into one of your six days of the year is kind of a feat in and of itself,” he said.

The festival announced its fall lineup in May, with The Avett Brothers, alt-J and Alabama Shakes headlining each of the three days, in that order. Other notable acts include Of Monsters and Men, Walk The Moon, Chvrches and Father John Misty.

Snow said the festival has an in-house talent buyer and works with Aaron Dessner, of the Grammy Award-nominated band The National, who helps curate a varied, appropriate lineup that fits with Boston Calling’s brand.

“We like to be able to put a pretty diverse show out,” Snow said. “We like to put out the best show that our group feels like we want to present to the city and to New England. An awful lot goes into it, a lot of yeses, a lot of no’s and three times as many maybes as you’d ever like to see.”

The lineup this fall is as eclectic as ever, with genres ranging from the hard electronic rap aesthetic of Doomtree to the folksy blues-rock sound of Alabama Shakes. On Saturday alone, festivalgoers will get to hear the moody, indie Father John Misty show, followed by the groovy disco jams of Canadian duo Chromeo within an hour of each other.

On Sunday, fans can enjoy everything from the catchy dance-inducing hooks of MisterWives to the heavy riffs of Hozier (who, if fans are lucky, might bring his creative cover of Ariana Grande’s “Problem” to the Plaza).

The festival also prioritizes bringing smaller local acts to the big stage during the weekend, Snow said. Grey Season and Dirty Bangs, two Boston-area bands, will open the show on Saturday and Sunday, respectively.

Two big changes to this festival include pushing the date back three weeks and the creation a mobile app for fans.

In previous years, Boston Calling has taken place the first weekend of September, or Labor Day weekend. The date was changed, Snow said, because that time of the year was simply too awkward to have a major festival.

“If you live around here, you know that transition from summer to fall is like getting the three year old to get dressed in the morning,” he said. “It’s like getting teeth pulled … I think that the festival being too close to summer and not really fall, it made things a little confusing. There was a lot of people who were in transition in their [lives].”

The app, on the other hand, shares the performance times for each day of the festival, allows fans to create personalized schedules and provides them with the latest news about Boston Calling.

With this interactivity and the exciting musical performances in mind, Snow said he still gets excited for every festival he puts on.

“The planning and everything is fun,” he said. “But once that first piece of equipment shows up before the festival and you go out there and work for four days building it, and then to see that crowd of people that inevitably sort of runs in right when the doors open, that’s one feeling of accomplishment.”