He ran the Build web design conference in Northern Ireland, and co-founded the XOXO indie artist and creator festival with Andy Baio in Portland, Oregon.

[12][13] In 2015, McMillan and Baio worked to open Outpost, a shared, pay-what-you-can workspace in Portland for members of the XOXO community.

[14][5] Outspace was open from February to December 2016, but ultimately shuttered due to high rental costs.

[15] McMillan co-founded the Suckerpunch non-alcoholic cocktail bar in Portland, Oregon, attracting a large online following in early 2020.

[1][16][17] After running several pop-up events, the COVID-19 pandemic stymied Suckerpunch's original plans to open a physical location, so they began selling non-alcoholic cocktail kits online.