Miner
You worked underground, mining rare elements or energy. Life as a miner is hard, even with all the technology available today, and it rarely pays well. You feel at home beneath the surface, and have learned not to fear the dark.
What were you mining? Why did you leave? Who employed you? Did you witness any tragedy, and if so how was it handled?
Flashlight, gas mask, multitool.
You are accustomed to dangerous environments and know how to negotiate them. You gain an expertise die on skill checks made to detect a trap or hazard.
Hardship breeds strong bonds, and you feel a connection to those you left behind. Perhaps you may get the opportunity to return and make their lives better in some way, or get revenge on the organization which exploited you.