Ask your co-workers in similar roles what they make. Or, reach out to people you trust at other companies. I won't post what I make here, as that could limit the range of future negotiations, but I'd be happy to tell you what I make in a private conversation on email or Twitter.
For software developers in Utah, USA, starting salary is $40k-$60k, growing toward $80k-$100k within 5 years and usually peaking at $120k-$140k a few years later. It's always changing, though, and certain skill sets or backgrounds can command a higher salary.
For my first real software gig I ask for what I thought was on the high end for someone with no real job experience. I felt like being on the high end was beneficial for me but also my likelihood to get the job. I feel like it demonstrated quality through price. I asked for $60k and they gave me the job.
Less than two years later I interviewed for another job and was offered 120k plus like 30k signing bonus. I didn't wind up taking the job (and still don't make that much because entrepreneur) but that was good validation.
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