You can call yourself a software engineer. You just need to have qualified with the professional body in charge of engineering. Like, say, a doctor or a lawyer.
Software lawyer sounds like you're a lawyer with a specialization. But ultimately I think it shouldn't come down to the specifics of what you call yourself since that's something people can weasel out of, but rather if you're communicating that you provide professional legal services.
as does "software engineer", but the title could be used in the US by someone who graduated a code boot camp, and doesn't know any engineering principles.
Programmers write the code, though. A better name might be "software legislator." Given that lots of us work on top of a giant, partially-understood heap of frameworks and libraries, that might actually be a more appropriate name than Software Engineer.
What about writing code for decentralized contracts, since contracts are lawyery but I’m writing software and have no formal legal background or credentials? Surely no one would object to me using the term “lawyer” for that!
I dunno actually, do you need to be a lawyer to write a contract? I think anyone can do it, right? You just might screw yourself over by missing an edge case or writing an unenforceable contract.
Feel free to just drop the "software" part, since it's a mouthful, and just call yourself a "lawyer." What's the difference anyway, we're all just typing words and numbers into computers at the end of the day.