(written from a Production point of view)
He broke into the industry in 1986 and has worked primarily as a penciller (occasionally inking his own work). His first job was backup stories in The Savage Sword of Conan that led to a regular job on Conan the Barbarian.
That led to stints on The Demon and Lobo at DC Comics working with Alan Grant on both titles. John Dell inked all of his Lobo stories. From there, Semeiks moved to Marvel Comics to work on X-Men and Wolverine, the latter written by Larry Hama, coincidentally Semeiks' first ever editor. Returning to DC led to work on JLA and Batman: Legends of the Dark Knight.
He has also worked for MAD Magazine and Paradox Press in addition to video game and toy design work.
In 1996 he contributed pinup art to Star TreX that was inked by John Dell.