Here are some places where you can find a co-founder (technical or not).
In searching for a tech co-founder you also need to be aware of what you bring to the table besides the idea. If the product is mostly or wholly tech based then you’re asking your CTO to do all the work upfront. Think hard about how you can even the deal - maybe you have necessary connections which can help the startup, maybe you are a good "salesman" to win early leads and generate revenue or investment, maybe you have marketing skills, maybe you have the money...or all of these. A prospective CTO will ask you these and you’ll have to be prepared to respond. You’ll have to win this person over to become your CTO and convince them that you and your vision are worth investing in. Like I said (and others said), it's like a marriage...and, like with all marriages, it can sometime go wrong so you have to be prepared for that too.
Things to consider
Remember when you partner with a CTO you’ll also be giving a lot away. You’ll need to provide a large chunk of equity and/or a salary, you’ll be giving up some decision making power and ownership. You’ll also be investing a lot in this person. Make sure you have the skills to assess whether this person is capable of building the product you need but can also bring the high level visioning for a technical product roadmap. We’ve worked with a few startups who have struggled to find CTO’s or who have wasted time and money on low value individuals demanding large salaries and equity, or taking several months to progress the project. The drain of such people can be a killer to young bootstrapped startups and founders can be left shocked months later when they’re tens of thousands of dollars down and don’t even have an MVP. It’s a big bet to play on one person but if you find right person they can skyrocket your startup!Good luck in finding the one!