I have advised a number of Clarity members on this question exactly. LinkedIn can be a great place to find your technical cofounder. I would look for someone who has been at their current company longer than 18 months and has relevant experience or interest in the problem you're looking to solve. Reaching-out "cold" can work, if you keep your message short and relevant.
Here's what a technical cofounder will need to see in order to feel comfortable joining you:
1) That you can fund and/or have raised sufficient money to cover the expenses up to and past launching the first version of your product.
2) That - in their assessment - you have what it takes to raise multiple rounds of funding (if the business is reliant on VC) or that you have what it takes to successfully bootstrap the business.
3) That you are realistic or at least credible in your assessment of the opportunity and have done sufficient customer development to ensure there is a viable market for your product or service.
4) That you and the technical cofounder have sufficient personal chemistry so as to want to and be able to survive an incredibly stressful and emotionally intensive journey together.
Happy to talk you through any of this in detail in a call and go into the specifics related to your location, background, and type of product or service you're looking to recruit a cofounder to.
I would suggest looking within your local Tech community. Search out various tech centric events through Meetup.com or look for something like a DemoCamp (or a Camp like event). Those events will attract people within the tech community that are interested in either new ideas, concepts or potentially becoming a cofounder. You could also look to see if your city has a Start-up Weekend. If you're comfortable, presenting your concept or through an event like that to see if you can match up with a passionate tech cofounder.
I had a conversation the other day with a UX specialist at Google. He has itchy feet and wants to leave. He happily told me he has a developer friend and a biz dev friend, both from Google, that are happy to jump ship with him. His major motivation "is to make a lot of cash".
The one thing lacking from his story is vision. In my experience, if you don't already have the friends (as the UX guy did), vision is the most powerful force for finding talented co-founders, partners and employees. The best developers I know (and I know some of the absolute best) are motivated by a desire to have an impact on the world: they want their code to mean something. They don't want to write code for code's sake. They want to leave a mark. Code is their vehicle.
My suggestion is to immerse yourself in the local scene. Make friends with the local tech guys at meetups and hackathons, at parties and dinners, and put yourself in a position where you can talk about the impact you want to have on the world. Irrespective of the platform or circumstance you use to meet someone, there is no escaping the reality that you need to have an inspiring story about how you want to make a change in society. If it's good enough, that story will spread and you'll get an introduction to someone that's interested.
Keep in mind that the best guys are employed and are being headhunted every day for big dollars. The best chance you have of finding a technical co-founder that is prepared to leave that massive paycheck behind is through a vision and credible story about how you can have broader impact.
If you want to find and attract someone with coding skills to join your venture, here are the tips I usually give people:
1. Find Where We Hang Out.
Note that this isn't just founder dating events and places where you're "supposed" to find us. There are other communities where programmers congregate that you could join if you do a bit of research.
Find a few technologies that might be relevant to the product and find some local meetups for those. Engage with us in online communities as well. I've made many strong friends over the internet, some of whom I've never met in-person before, one of whom I even started a (now failed) business with a year ago, without us ever having been in the same city.
2. Realize What You're Asking For.
The most frequent mistake I see "idea" people make is grossly underestimating what they're asking for. Don't explain your entire concept and then ask how many days or weekends we could build it in.
Starting a new project from nothing takes a long time, even if the developer is experienced. You're not looking for a "quick favor", you're looking for a cofounder and some serious commitment.
3. Don't Be Possessive.
If the relationship works out and we come on board to start building, it won't be "your" idea anymore. The concept *will* morph and change as it runs into the real-world constraints of technology, resources and time. You have to be willing to trust our judgement on some of those decisions.
4. Demonstrate Your Value.
If we're deciding whether or not to join your project and add our valuable skill set to the venture, we need to know that you're generating value as well. And no, "having an idea" does not constitute adding value.
What will you be doing while we're sitting in front of our keyboard for hours and days and months? You should be out interviewing potential customers, analyzing the market and competitors, setting up some branding and a basic landing page, growing an email list of interested users, working on the company's pitch and marketing/sales copy, and setting up an industry blog with regular content about your industry.
Ideally, you'll have started doing all of these things before you started looking for a technical cofounder. If you can show that your idea already has demonstrable traction and potential, you'll have a much easier time finding someone to help you.
5. Be Cool.
This should go without saying, but don't be snobbish. Don't tell us how your idea is the next Facebook or Google and we better get on board before we miss out. No one responds well to those kinds of things.
The conversations I get most excited about are the ones where someone comes to me genuinely just asking for feedback on their product or idea, with no sales pitch of "you HAVE to build it for me."
Despite common social stereotypes, coders are people with feelings and opinions just like you. Think of it like a date, if there's no initial chemistry, the relationship (and potentially, the product) are doomed to fail. Just be cool.
I've written about this a bit more extensively on my blog: http://blog.hartleybrody.com/find-a-coder/ Feel free to give me a call if you'd like some feedback on a product concept!
Having been involved with technology-based startups for almost 20 years, this is probably one of the most important questions - who should be co-founders? Considering this is your business, you need to be comfortable with the co-founder you bring on board. In my opinion, the key characteristic is trustworthiness. The co-founders of my previous ventures have all come from my network - people whom I've worked with in the past. That way I know their personal traits as well as their technical capabilities. If this isn't an option for you, then here are some possible places to look:
1. Co-Founders Lab - check to see if there's a Co-Founders Lab in your area.
2. Local technology group meetings - depending on your technical needs, attend appropriate local meeting such as those with IEEE (electrical engineers) and ACS (chemists). There are technical associations for almost any technical discipline so find out what is available in your area.
3. Local Universities - if you are located near a research university, then you may be able to find someone interested in startups there.
4. LinkedIn - you can search for people with the right technical discipline.
Regarding attracting or convincing someone to be a co-founder, this should be secondary to you being comfortable with the person. Each person will be different regarding their comfort level in joining you. Some will want a certain salary, some will want equity, some may want autonomy, etc.
Good luck with your new venture. Feel free to follow up with me if you need any further advice on attracting a technical co-founder.