If you want a lightweight, secure, modern OS, consider:
Elias wasn’t a hacker in the cinematic sense; he was a digital archeologist. He lived in the "Gray Zones," outskirts of hyper-urban cities where high-speed fiber didn't reach and the hardware was decades old. In these regions, the standard, bloated operating systems of the modern era were a death sentence for a computer. They demanded too much RAM, too much telemetry, and too much power.