Smoak Technologies was founded in March 2019 after Curtis Holt transferred full ownership of Helix Dynamics to Felicity Smoak. Shortly afterwards, Felicity hires Alena Whitlock as the CTO and the two began working on Archer, the DNA tracking program developed by Felicity.
By 2040, the company had fallen into dissolution, Felicity led William to the company via coordinates. Felicity was believed to be dead, but she was in fact alive and being held hostage by Eden Corps.
In 2031, Star City was invaded by Grant Wilson/Deathstroke's army and when most of Team Arrow were killed and Oliver incapacitated and presumed dead, Felicity left, deeming the city a lost cause. Before leaving, she had most of her projects relocated for safekeeping.
In 2046 the building was shown to still be standing. To repair their ship Rip, Sara and Connor broke into the warehouse where Felicity's projects were being kept to acquire the technology they needed.
DC's Legends of Tomorrow