Before moving into venture, Julian Mattes led payments and deposits teams at Deutsche Bank and Commerzbank, and he later credits his years training in decathlon and triathlon, including national championships, for shaping his belief in hard work and following conviction—an approach that shows up in his investing style, where he builds quick conviction while stress-testing a company's market and scaling potential, and where he believes a fast no serves founders better than a slow yes. At Yttrium, he focuses on Europe's missing middle of later-stage funding, often framing funding rounds around whether a founder keeps control of their company and how investors can concretely help by shaping boards, opening doors to follow-on rounds, and enabling strategic exits, with hands-on involvement across companies like CleverConnect, Upsun, quantilope, Cosaic, Truce, Seven Senders, riskmethods, and orderbird.