PMI certification matters more to some companies than others. For technology companies that provide services to other tech companies (such as project-based development work), such certifications can really help you stand out from other people who don't have them. If you're set on this, do your research ahead of time -- check job descriptions for what you're applying for and see if any of them call this out as a preferred qualification.

My feeling is that actual technical knowledge of the field might stand you in better stead in terms of your overall hireability than just a PMI certification, for a few reasons:

1. When money is tight, tech companies will prioritize hiring for positions that build or develop new products that can go to market. So, software developers have a fair amount of built-in job security because their work directly impacts future profits. Project managers are significantly more disposable because while they help make sure all the deliverables for a product are delivered on time, they don't often produce anything intrinsic that adds to the overall profitability of the product. (And sometimes the logic is: why not get a dev lead to do the work?)

2. Technical literacy is ALWAYS going to improve your hireability. Ask yourself: if you had the opportunity to hire a PM who was PMI certified, but didn't have in depth knowledge of the coding processes involved in dev, OR, you could hire a PM who had deep technical knowledge but no certification (though a knack for project management), which would you choose?

I think you should build your technical skills first and THEN if you find that people are requiring the PMI certification, then go for it. There are lots and lots and lots of very capable PMs out there who've never gone for certification.