Duff looked casual and cute for the outing at Alfred Coffee in Studio City, California, sporting ripped jeans, and tied-up flannel button-down and cute booties. Koma also went for the distressed denim look, wearing a white T-shrirt, black jacket and cool shades.
The pair also reportedly spent the long weekend together at Santa Barbara's San Ysidro Ranch -- the same hotel Duff spent her wedding night with then-husband Mike Comrie in August 2010 -- where they were seen kissing at a restaurant, according to Us Weekly.
Koma, who produced several tracks for Duff's fifth studio album, Breathe In. Breathe Out. in 2015, was last linked to Carly Rae Jepsen, whom he dated from 2012 to 2016.
Duff, meanwhile broke up with Walsh in December, just five months after taking their romance public. The Younger star's divorce from Mike Comrie, with whom she shared 4-year-old son Luca, was finalized in February 2016.
Earlier this month, Duff opened up about dating to Cosmopolitan, revealing that she wasn't "desperate" to find a man.