Hi Andrew,
We too are self implementing, have about 35 team members and do engineering, sales, installation, manufacture, software, etc. Very tricky when you are highly vertically integrated and have a lot of complexity for a small organisation.
We have people filling multiple roles in the accountability chart. Today I am the CTO, Marketing Manager, CEO and shared services manager (HR, legal, insurances). My COO is also the Sales Manager, Production Manager and Procurement Manager. We are hiring a full time CTO at the moment, but don't expect the accountability chart to change, just some of the names in it.... (More)