The brothers · AJ2
Julien Lepleux
Angel investor, founder and growth operator.
Julien Lepleux is a partner at AJ2, the deep tech angel investment vehicle he shares with his brother Adrien. He co-founded MoldCo after working in venture investing and startup growth.
Investing and operating
Julien was previously Principal at Bleu Capital, a family office investing in companies and venture funds. Earlier, he worked on growth and operations at Cargo, later known as Ara Labs.
At AJ2, his investments with Adrien include Exodys Energy, Firestorm, The ImmuneCo and Catalyx Space.
Writing
Julien writes Engineered Grains, covering hard tech, investing and company building. Selected essays include Embracing the Uncertainty in Hard Tech Investing, Selling Nuclear with Carl Perez, and Make Hardware Great Again.
AJ2 investments
Professional background reviewed September 2026.