After the Storm by Key Dyson, Raymond Roach, Hannah Birchwood

Rich Merrill, gene-tweaked supersoldier by birth and AI support technician by vocation, is done fighting. Finally reassigned after four hellish years aboard the Sympatico, a dysfunctional ship with a deadly crew, all he wants is to make the most of his second chance. The survival skills that got him through his last posting aren't going to help him on the Reliant, though. In among a kinder, gentler crew, Rich's old scars and bad habits are just as much of a problem as vengeful ex-crewmates, or the Sympatico's corrupted AI, which wants him back. Rich wants to be a better person. He wants to make some friends, finally. He'd especially like to be friends--or more--with Basil Wright, a brilliant teen rival who's grown up captivatingly handsome; or Liam Beaker, a beautiful, mercurial botanist and fellow tweak. Rich wants to reconnect with what's left of his family, pick up some hobbies, get some sun, learn to relax. But if he can't learn how to leave his old life behind, his new life won't be worth living.