As the founder of a company, you will likely play many roles across the life of the company. The core tenet of being a founder is that you should do whatever it takes to make your company successful.
Although my title at Color for the last ~4 years was CEO, at different times I played the role of recruiter, supply chain lead, product manager, office manager, and head of sales. Similarly, my 3 other co-founders played a variety of roles across engineering, design, PR, genetics, and other areas. As Color has grown we have hired smart experienced people to take over these areas. It is always a magical moment (and a relief) when you find a smart, experienced person to take over a function from you who does the job much better then you ever will. The role of the CEO is, in part, to find amazing talent so that the company as a team is as strong as possible. Many startup CEOs think they themselves need to be great at everything, which leads to all sorts of bad dynamics. Startups are fundamentally a team sport.
My co-founder Othman Laraki and I have been working together for 9 years. We co-founded MixerLabs together, were acquired by Twitter, and then co-founded Color together (along with Taylor Sittler and Nish Bhat). Traditionally over the last 9 years of working together, he and I have divided up roles with me as CEO and he as President. While we ran different areas of the company between us (I ran most business functions, the lab, and science; Othman ran product, engineering, design, PR) in practice the lines were more blurry and there was redundancy between us. Since we made major decisions together, this created both inefficiency in where time was spent, but it also slowed us down. Teams needed to be able to schedule both of us for every key meeting, and people bounced back and forth between us to get to a decision.
As Color scaled to 80+ people, Othman and I decided this structure need to change. We felt that the company needed a single decision maker and owner of the day to day operations. We spent some time talking through scenarios between the two of us and then discussed it with our amazing board of directors (Hemant Taneja and Sue Wagner).
We wanted to create a structure with the following characteristics:
A. Clear decision making and ownership of areas
B. Something that would keep us both involved full time with the company
C. Allocation of roles based on where we thought the future of the company lay to maximize the impact and value of the company and its products. As a software company dealing with important health information, we wanted to re-emphasize both the technology roots of Color, but also the patient advocacy side of what we are doing 
In the end we were most excited by a structure where Othman would move to CEO, and I would move to full time chairman. My reports would move to Othman, freeing time up on my end and giving him direct operational control. This means Othman could make decisions unencumbered, and I could focus on four areas we both felt were key to the future of Color. As part of this process it was important to ensure there was a clear breakout of roles so that people internal and external to Color would know who to go to for what.
The next steps were to communicate this decision. We started with our major shareholders, then my direct reports, then the company, and then our smaller investors. The last step was to let people know externally what had changed. We thought about skipping a blog post about it as not much is really going to change at Color day-to-day, but in the end our spectacular CMO Katie Stanton convinced us that this could be good information to share as almost a "how to" for other entrepreneurs facing similar decision points. As a sucker for entrepreneurs blogging experientially to help each other - I fell for Katie's reasoning. Hence this post :)
Our goal for Color is to empower people, their families, and their healthcare providers to make more informed health decisions. We think this new structure is the best way to achieve the world changing goal.
 Othman is a BRCA2 carrier and has breast cancer in his family. The lack of affordable, high-quality, streamlined, available genomics and genetic testing is part of what drove the four of us to found the company.
 The four areas I will focus on include large deals, engineering hiring (I am going to focus on female and diversity hiring in particular), longer term product roadmaps, and short 3-6 week projects that need executive bandwidth but lack an executive sponsor.
 Our first two calls were to Vinod Khosla from Khosla Ventures and Joe Lonsdale from 8VC. Their insights, wisdom, and feedback are always spot-on and helpful.