Hi and welcome to the forums!

It sounds like you've got plenty of experience and the right background to make a go of your move to Portugal. The biggest challenge is always that of getting a visa, because normally you need a valid reason for relocating to the country. Finding that job ahead of time is usually the easiest way to go, particularly if the employer is willing to help with the visa.

You may want to take a look at the EU site on working in Europe: EUROPA - EURES - the European Job Mobility Portal

They have specific information on the various countries in the EU (in various languages) and you might find some of the information there useful in the job search.
Cheers,
Bev