I've been using computers and programming them for over 30 years, albeit self-taught with no official qualifications.
Do you have a portfolio of projects that can be presented to potential employers? It could be in the form of a website or a GitHub profile. If you happen to have been contributing on Stack Overflow, that could be used as a strong indicator of your skills too.
While obtaining a certificate would be a good idea, it's more suited for individuals who are new to the domain and lack a decent experience (or the domain is highly specialized). Also, going the certification route could be a bit lengthier route if your immediate goal is to get a job and enter workplace quickly.
If you have a presentable portfolio as above, with projects that you worked on in recent time, it can give a potential employer confidence about your skills.
I'd use this to go ahead with applying for job via various good job boards on the Internet.