Question - are the non-technical employees requesting work done by the senior developer directly to him? Some developers are often just that - hard headed code

Question - are the non-technical employees requesting work done by the senior developer directly to him? Some developers are often just that - hard headed coders, if they haven't come from a role or a background that has required them to "Customer Facing" then you need to re-evaluate the reporting chain or if it is crucial that they be "customer facing" then you need to broach the subject with him that he needs to understand how to talk to them. As CTO of a small company you should head up the engineering team, if required you will need to act as the go between to get the requirements distilled into a format your senior dev can then action with the rest of the team. If you cant absorb this responsibility then you need to get a project manager of some sort in to manage it :)