Just as a gut check: 25% of the company for 200k is a lot of equity for a low price. That's a yellow flag to me. It says to me that the investor doesn't think the company will grow huge and/or there should be room for future investors.

I'm not sure what you product or idea is, but companies where technology is the core tend to have all founders (or N-1) capable of building product. You have 1 of 3, so what are those other two folks doing? Again, a yellow flag. In terms of the business, I'd worry this is going to be low margin, if it takes 2x as many sellers to sell as it takes builders to build, from day 1.

Technology is leverage, and you're the only one building the lever that lifts this company off the ground. My advice is to make sure your founders understand this and to make sure all three of you are focused on building a true MVP. You need to build something that is easy to set up, easy to use, and delivers true value. Your cofounders will smooth over some of the rough edges, but push hard on making sure you're aiming for product-market fit in a good market.

If not, you'll end up as the IT group for a consulting business. It's not a bad gig, but it's not the startup journey you've probably come to this website to talk about.