Complex sentence: Hirschhorn's entry into the tech world came in 1995 when, as a student, he started the website design firm Mischief New Media, which focused on building sites for major label artists.
Split into simpler sentences: Hirschhorn's entry into the tech world came in 1995 when as a student he started the website design firm Mischief New Media. The company focused on building sites for major label artists.