The Giants on Friday announced that they had hired Joe Schoen as their new general manager, the first step in the team’s attempt to fill a leadership vacuum after the previous general manager and the former head coach both departed after another unsuccessful season.

Schoen, 42, spent the past five seasons as the assistant general manager of the Buffalo Bills, helping Brandon Beane construct a roster that reached the A.F.C. championship last season. The Bills face Kansas City in the divisional round on Sunday. Schoen replaced Dave Gettleman, who retired as the Giants’ general manager this month.

“Throughout our search, Joe impressed us with his ability to communicate a progressive and comprehensive vision for our team,” Giants president and co-owner John Mara said in a statement. “His philosophy and collaborative approach to building a roster and coaching staff align with what we were looking for in a general manager.”

Gettleman, who became general manager in 2018, retired shortly after the regular season concluded and the Giants had limped to a 4-13 finish. They never reached the playoffs during Gettleman’s tenure, and the two coaches he hired, Pat Shurmur and Joe Judge, went a combined 19-46, the team’s worst four-year stretch since 1975-78. The Giants fired Judge this month.

In his four seasons as general manager, Gettleman’s high-profile draft selections underwhelmed. Running back Saquon Barkley, whom the Giants chose with the No. 2 overall pick in 2018, has not played a complete season since his rookie year because of injuries. Daniel Jones, selected No. 6 overall in 2019, has continually lacked a strong offensive line, and his play has not offered a concrete answer on whether he should be the team’s long-term quarterback.

Mara and co-owner Steve Tisch interviewed nine candidates. Mara said they were drawn to Schoen for his collaboration skills and his vision for the team.

In Buffalo, Beane and Schoen drafted Pro-Bowl quarterback Josh Allen and executed smart trades for safeties Micah Hyde and Jordan Poyer and the receiver Stefon Diggs, among other players. Schoen hopes to apply that discernment with the Giants.

“Our goal is to build a roster that will be competitive, have depth, and most importantly, win football games,” he said in a statement.

His first major decisions will be the hiring of the team’s next coach and a determination about Jones’s future. The Giants have not reached the postseason since 2016 and have not won the N.F.C. East since 2011, a season they also won the Super Bowl.

Jones is on the last season of his rookie deal, and the team must decide by this spring if they will pick up his fifth-year option.

And as Schoen considers his options, he will now have the pressure of the top job and the scrutiny of a new set of fans in the N.F.L.’s largest market.