Accepted a below-market offer for my first job on purpose and renegotiated a year later with numbers to back it

Needed the job more than I needed the ceiling at the time, so I took a number I knew was low just to get in the door and start building a case. Tracked what I shipped for twelve months, brought a specific list to my first review instead of a vague "I think I deserve more." Got most of the gap closed in one conversation. Wouldn't recommend it as a strategy for everyone, but it worked for where I was.