What makes a exceptional/great CTO for a startup?

I think it depends on the what stage the startup is in. In the early days(V1 product or under 30 employees) of the startup, its not about the title. Whether its, CTO or head of engineering or head xyz, or just an engineer, what matters is bringing clarity to the founders vision and razor sharp focus in executing the founder vision. Here execution implies that build, get feedback from customers, incorporate the feedback if it make sense and iterate again. Quicker and faster this iteration is, its better for the startup. So as I said earlier its not the title. Can THE guy facilitate this ? Can he bring clarity to founder vision ? Can he execute with all the constraints like time, money and resource ? If he does all of this he is successful. Eric Ries talks about execution in great detail in his book Lean Startup and in here https://www.startuplessonslearned.com/

There are two primary roles that a CTO has to play: (1) Ensure that medium term and long-term objectives of the organisation is fairly clear to his/her team and (2) Identify and remove all the roadblocks from the path of Engineering team (and it includes dev/devops/qa/support). The first requires him/her to be a great communicator (and by that I don't mean his/her capability to drop buzzwords about). A CTO should be able to 'influence' his team and peers positively and that presupposes an affinity and ability to communicate. The second requires him/her to have a thorough understanding of the recent history and future direction of technology, as well as to have grasp of what makes the engineering team function well. This obviously means that s/he is comfortable with the choice and implementation of tech-stack and holds a discussion, well! In a Start-Up, a CTO will almost always be coding/building too - so that's a given - but as time progresses and team grows, s/he should be more focused on identifying potential opportunities to add value, spotting possible integration with other applications/platforms, publicising APIs, enumerating parameters of performance, patterns of customer interactions and keeping the overall architecture together.

Thanks Ancy, I'm about to become the CTO of my company so I'm super interested in the results from your survey. From my experience, I can add a few things: 1. Ability to think about the platform wholistically, how changes or optimizations in one part of the platform may affect others. 2. Dependency management. Making sure that engineering teams aren't ever blocked by product, design, infrastructure, or other engineering teams. 3. Simplification. Making sure business needs are translated into the most technically simply designs that still meet the core business needs.

Well I can comment about the traits I would rather not associate with an exceptional CTO based on my experience at 4 startups: 1. Thinking just from the technology perspective, and not working backwards from the customers, which often results in building awesome technology with no takers. 2. Building products without defining the key success metrics for the product and not having any mechanism to measure those. 3. Hiring a Head / VP / Director of Engineering and not giving them full authority over engineering. Either relinquish some control, or don't hire someone in the capacity of "head". Have a clear division of responsibility. 4. Assuming that you are the best developer around. Teaching developers how to fix the bugs, how to design, how to write the code is not a good use of your time. 5. Sacrificing the quality of the design/code with an excuse of too much ambiguity and fast changing requirements. Ideally your design should be extensible enough to cater to such deviations to a certain degree.