Attaochu attended Archbishop Carroll High School in Washington, D.C.. He played football for Archbishop Carroll. He had 118 tackles and 14 sacks as a senior, while recording four touchdowns by blocking kicks or returning fumbles. He played three seasons of varsity football as a linebacker and defensive end, and served two years as team captain.
Considered a three-star recruit by Rivals.com, he accepted a scholarship from Georgia Tech over offers from Illinois, Kansas State and Syracuse.
As a freshman, Attaochu played in all 12 games and started in the Independence Bowl. He finished the year with 23 tackles (18 solo tackles), 4.0 tackles for loss, 3.0 sacks, and one quarterback hurry. In 2011, he played in 11 games and started 10 times, missing two games due to an injury. He led the team in tackles for loss (11.5), sacks (6.0) and finished third in total tackles with 59, intercepted one pass, while breaking up two others and recovering a fumble, earning a conference honorable mention selection. In 2012, he played and started in 13 games. He registered 69 tackles, including 44 solo tackles, had 12 tackles for loss, 10 sacks, one forced fumble and one fumble recovery. He had two sacks in the ACC Championship Game vs. Florida State. In 2013, as a senior, he played and started in all 13 games, recording 45 tackles, including 16 for loss, while adding 12.5 sacks, two pass break ups and one forced fumble, while earning himself All-ACC and All-American honors.
He finished his career as Georgia Tech's all-time leader in sacks with 31.5, surpassing Greg Gathers' 31 that he set between 1999 and 2002.
Attaochu sat out drills at the 2014 NFL Combine due to a finger injury (medical exclusion). However, he was able to participate fully on his pro day. He ran the 40-yard dash in 4.58 and a 4.63, had a vertical jump of 37.5 inches, a 3-cone of 7.28, and a short shuttle of 4.64. His 10-yard split was 1.55.
Attaochu was selected by the San Diego Chargers in the second round of the 2014 NFL Draft. In the 2014 season opener against the Arizona Cardinals, Attaochu made an impressive debut, recording one strip sack that forced a fumble and one blocked punt. The two plays helped set up 10 points for San Diego in an 18–17 loss.
In 2016, Attaochu missed three games with a sprained ankle suffered in Week 6 and then suffering a broken foot in Week 10. He was placed on injured reserve on December 3, 2016. He finished 2016 with eight tackles, two sacks, nine pressures and seven quarterback hits over eight games.