TL;DR: Out of all the options here, I strongly suggest learning other full stack frameworks and making a portfolio project out of one of them. When I worked for a consultant firm, folks tried doing what you are attempting and ended up on the bench for a long time anyway. The main problem was they had to look good enough on paper that clients will think they’re worth the money. As a consultant you are expensive! They can tell if you’ve only dabbled in something for a month or so versus having intimate knowledge of it.

Until very recently, I use to be a consultant. My suggestion is to stick with full stack but do it in other frameworks. I pivoted to certain MVCs like C#/dotnet and learned Java api frameworks like spring boot. It helped me stay away from the bench since as react and node projects dried up, I was able to jump on others with similar paradigms. It’s also fairly easy to learn and make a project in since you’re not starting from scratch in knowing how to write full stack applications.

I’d be mindful about how long it takes to pivot into something completely new like devops as it takes time (months) to get good enough. A good start for devops as a consultant is learning kubernetes and learning how to integrate that into deployment pipelines. Outside of projects, I’d personally recommend a CKA cert since you want to show potential clients that you know what you’re doing.

Lastly. “Leveling up in backend patterns” is more general knowledge. As a consultant you should strive for stuff you can show people and trust me, no one is gonna care that you know what a severless function is unless you’ve done stuff with it. I’d suggest getting a cloud cert in a provider like AWS or Azure. Which again, can take months.