I freelance. Though that journey is going to greatly slow down because I recently got a very high paying job.
Oh yeah, I also wanted to say that like you, I have a background in Engineering. Apart from what AGF said above, I want to add: I am not discouraging you from learning front-end dev. I am just cautioning you that, for almost every skill in the world (except for ones needing a very high level of education like Masters & PhD), you can almost always guarantee that there are lowballers in price.
If you still do not know what value looks like, I'd like you to do an exercise and write a log about this:
Look if there is a job opening you like (for example: front-end dev or aerospace engineering), then take the effort to hit up recruiters & managers in LinkedIn. Say you're interested in the role; and you'd like to have a quick chat about them, the company, and some of the problems they're having in the company. Say you'll buy them lunch/ whatever you can offer to make it look like they're not wasting their time.
^By doing that, you will be able to see what they value. Maybe it's to create a project to automate some processes, saving them hundreds of thousands of dollars/ whatever currency you're using in labor. Maybe it's to build their authority online to improve online presence, to drive more sales. If you like the sound of the problem you're solving, you can double down on it, and go to interviews selling yourself your skills. And, you will also know their problems and speak it to them, which is a plus,
Sales calls as a freelancer & job interviews as a candidate are very similar; I do all this in some form with my prospects. I also do this when I was interviewed & landed a very high paying job. Just doing what I said will put you leagues ahead of everyone because they only care about salaries, while here you are talking about business problems.