This article explains the options for visas. Based on your situation, I don’t think you could receive a highly skilled foreign professional visa, as I can’t see how you’d get more than 60 points (10 for JLPT N2, 10 for being 30~35, 40 for a salary of ¥10 million per year). Since you don’t have a degree, I think the only other option is passing a recognized exam like the PhilNITS Fundamental Information Technology Engineers Examination to qualify for an engineering visa.
As for your chances of finding employment, it’s unlikely you’d find a company willing to hire you from abroad, as generally companies will be looking for someone with proven experience to take a chance on relocating them.
The best route to Japan would be to focus on growing your career locally first, as you’re much more likely to be able to find a company to take a chance on you if you don’t need to deal with things like visas or relocation.