Kwiatkoski attended Bethel Park High School where he played wide receiver and safety.

[4] On January 30, 2016, Kwiatkoski recorded three combined tackles as part of Dallas Cowboys head coach Jason Garrett 's North team that lost 27–16 to the South.

On April 1, 2016, Kwiatkoski participated at West Virginia's pro day, but opted to stand on his combine numbers and only performed positional drills.

[6] At the conclusion of the pre-draft process, Kwiatkoski was projected to be a fourth or fifth round pick by NFL draft experts and scouts.

[12] He ended the 2017 season as the third-best inside linebacker in run-stop percentage and fourth-best in pass-rush productivity according to Pro Football Focus.

In the game, he recorded a team-high ten tackles and sacked quarterback Kirk Cousins once in the 16–6 win.

[17] In Week 10 against the Detroit Lions, Kwiatkoski recorded a sack and an interception off Jeff Driskel in the 20–13 win.

[19] In Week 8 against the Cleveland Browns, Kwiatkoski forced a fumble on tight end Harrison Bryant which was recovered by the Raiders during the 16–6 win.

[20] In Week 10 against the Denver Broncos, Kwiatkoski recorded his first interception as a Raider off a pass thrown by Drew Lock late in the fourth quarter to secure a 37–12 win.

[21] In Week 12 against the Atlanta Falcons, Kwiatkoski recorded his first sack of the season on Matt Ryan during the 43–6 loss.

[28] On October 16, he made his season-debut after being inactive the first five weeks of the year, with one tackle during a 28–14 win over the San Francisco 49ers.