Baker is known for being a session and touring guitar player for the likes of Olivia Rodrigo, Miley Cyrus, Demi Lovato, Adam Lambert, Bea Miller, Bonnie Mckee and many others.

In 2004, Heather Baker and a group of friends formed the band As Night Falls, releasing their debut EP The End of All Innocence in 2004.

She joined vocalist Aja Kim, guitarist Sara Marsh, bassist Wanda Ortiz and drummer Linda McDonald as part of the Maidens' 2007–2008 lineup.

In 2013, Baker began commercial composing and arranging for feature films and television including soundtrack music for Holy Ghost People (2013), Raised by Wolves (2014), A Beginner's Guide To Snuff (2015), Little Paradise (2015), The Night Watchmen (2016), Dead Draw (2016), Cynthia (2017), Embeds (2017 TV series) and Starlight (2019).

Her direction clients include Olivia Rodrigo (Driving Home 2 U), Tegan and Sara, Towa Bird, Ricky Montgomery, Em Beihold, Chappell Roan, Peter McPoland, Meg Myers and many more.