The application booted in half the time. The memory footprint dropped by thirty percent. The log files, once a chaotic scream of deprecation warnings, fell silent.

Then, from the main lobby display, a cheerful jingle played. The ATM test harness fired up. Transactions flowed like water. The old mainframe emulator, now wrapped in a modern HTTP client, shook hands with JRE 17 without a single complaint.

Leo threw up his hands. “See? I told you. Burn it down. Rewrite in Go.”

She looked at the console one last time. Somewhere in the digital ether, a million virtual threads were sleeping peacefully. The switch expressions were clean. The records were immutable.