In 2015, he also reached the semi-finals of the Championnat de France - Coupe Ganay, and in 2016, he was runner-up at the Lytham Trophy in England.

[2] Coussaud represented France at the 2016 Eisenhower Trophy together with Jeremy Gandon and Antoine Rozner, where he finish 10th individually.

He also played in the 2016 European Amateur Team Championship, where France recorded the best score in the qualification round, but fell to Sweden 21⁄2–51⁄2 in the quarter-finals to finish 5th.

He finished runner-up to Lukas Nemecz at the Gösser Open, and secured his maiden professional win the following week at the Open Golf Clément Ader Paris, where he defeated Spanish amateur Adri Arnaus on the 5th hole of a playoff, having started the day 9 shots back of the lead.

[6] In his rookie season on the European Tour, he finished runner-up at the 2024 Qatar Masters, a stroke behind Rikuya Hoshino of Japan.