Yuri Stern is their chosen name (and it’s androgynous because “Yuri” is the transliteration of either a male Russian name or a Japanese female name (the latter is more likely, given the prominence of German and Japanese in the game); even their prior (presumably dead) name, featured in prior games, is androgynous), and they use they/them pronouns. I didn’t find info about their gender but wouldn’t be surprised if they considered themselves lesbian (enbys can be lesbian too). The other dev, Barbara Wittmann (aka antihelios) is likely a woman (uses she/her pronouns). They are featured in a “Women in Gaming” listicle but that’s hard to trust. They seem to keep their personal info (gender and relationship status) private.