Every time you book a flight or check a hotel room, your request is routed through a green-screen mainframe system that traces back to the 1960s — and the entire multi-billion-dollar travel industry still relies on this ancient digital foundation because replacing it would be enormously expensive, dangerous, and slow (opens in new tab)

When you book a flight on your phone — a clean, modern app with smooth animations, real-time pricing, and one-tap payment — the part of the system you’re touching is the very thin, very recent layer at the surface. Underneath it, almost invariably, your request is being routed into one of three vast, deeply old […]