Background: I'm a non-technical founder that has contracted a B2B SaaS MVP.
Now I've started getting clients that are interested in purchasing, and will need to start making improvements.
What should I give equity wise to CTO/1st engineer hire coming on? This is still part-time.
But even if I am a developer myself, I disagree.
There is a tendency on HN to consider the technical people in a company as the ones that contribute the most. In my opinion, that is often not the case.
In fact, someone even called you "the idea guy", as if all you did is having the idea.
I think that, as others have pointed out, the sensible approach is to split equity based on the value brought to the company. But value does not equal necessary effort, time spent or "tangible" output in the form of code.
While a CTO might spend a lot of time building "tangible" assets which are definitely important, that is not the only value brought to this company. There are assets other than code.
You went through the process and the risks of validating the product and bring in the first customers. Those are assets too and are what makes the business exist in the first place. Without those, all the code a technical person can produce is worthless.
So I would say you should consider the value this CTO will bring to the company and compare it to the value you already brought yourself and will bring in the future.
All in all, though I think that proposing anything from 50% up for the CTO like others are doing in this thread is not reasonable.
Also consider that with an even split, it will be hard to take a decision when you disagree with each other. Someone must be able to have a final say on each matter. Since I doubt you want that person to be the new one you will bring in, I would say that their share should be from 49% down.
Finally, it's not in your question, but do you need a technical founder? You might, so you are the only one that can answer this. But also consider that, since you have clients that will bring in revenue, you can just use that revenue to hire someone on a contract basis first and on a stable basis later, without slitting the equity.