Was given a job offer over the phone but no written letter, it was the end of the year and for whatever reason kept putting off the official offer letter. I had another job offer come up while I was waiting for Zymergen, and Zymergen told me that I should remain patient because the official job offer was coming soon. I turned down the other job offer and then a few days later I received a poorly written email stating the position was no longer available. I was told it was "a last minute decision by the management." Extremely unprofessional, do not recommend.