Ask HN: Where should I start as a 34-year-old switching to software as a career?

You say you lack experience but you don't say what experience you do have. Do you lack experience compared to a 35 year old software developer, or compared to a 21 year old computer science graduate? It will take you years to catch up if you're starting from zero. Don't think about it as a career change. Think about it as a new hobby. If you think you're good at it one day, then try to find a job where you need it.

I'm looking for someone with lab experience to contribute to some open source software, I used to teach web-application development. Would like to trade experience, my HN handle at gmail.com

Find a bootcamp that has a good record for placing people into jobs, or advertises it, or has a reputation, or has aligning incentives to do so, or whatever. Your first job doesn't have to be anything glamorous, but should then allow you to get to eventually wherever you want to be in your software career. Some of these bootcamps have skill/interview requirements, so that will help direct where your home study and practice should be.

Or, you could go to college and get a master degree in CS. Colleges then have on-campus-recruiting and some set of companies that will basically hire anyone who graduates from the university with a CS masters degree. It's the same idea as the bootcamp; go somewhere with the connections/infrastructure in place to help you get your foot into the industry.

Now, once you have your choice of companies to choose from, I tend to recommend startups. That's the one place where you have the opportunity to do things that you definitely shouldn't be doing given your experience level. But, since they have so few employees and so much to do, you're it. Then with those rapidly acquired skills, and with a year or two of relevant experience now on your resume, you can more easily get a cushier, more stable job at a larger company, if you wish.

If you work in a lab in microbiology you already have the mindset for detail, dedication and testing that development requires.

Since development is problem solving, find something that you can solve in your field, a tool for other microbiologists maybe (web, app, content, tool), and build a prototype. Keep iterating on projects, and ship to the world in whatever tech you find fits your style. Or do something entirely new in a field you want to work in, I prefer gaming, promotions, household management and more, but find one that you will enjoy.

Having a project to work on will propel you through all the walls, from design to develop to ship to maintenance, the full cycle. The projects might be subpar initially as with anything newly learned, but they will be very empowering because you will hit some shots on the fairway and green even if you spent some time in the rough and sandtraps. I still love the feeling of solving problems and shipping games/apps that people play or use, almost a drug.

Don't worry about age or your field, you are too old when you are dead, and you clearly are alive with motivation to want to make a move.

A great coder who shipped solid products and fun stuff that I worked with was an agriculture major and worked on farms initially.

This was me 3 years ago! I was an academic cellular/genomics lab tech and now I write software.

Have you tried programming? I got my start with python courses on coursera and udacity, then moved on to solving problems on Project Euler. A few years after my first taste of python, I started going to meetups, then researched and entered a boot camp, graduated, and got my first job.

I went into the boot camp knowing that I liked programming, and that was important. I'd strongly recommend you see if you have that inclination as a first step.

Personal projects are great, but as a project manager told me in an information interview, a well chosen boot camp can provide you with structure and accelerated learning.

"too old to ever get a job in the field": I was only a few years younger than you when I started my boot camp. I don't think your age should dissuade you from trying. Your age = experience you have in a different domain, and in my experience, helps with the learning, application, and working process.