Real-Time Decoding: The Classical Control Layer Inside Quantum Computing
Why fault tolerance depends on low-latency classical infrastructure
Quantum fault tolerance is often presented as a problem of better qubits, lower physical error rates and larger processors. That framing is incomplete. A useful fault-tolerant quantum computer also requires a classical subsystem able to interpret error information continuously and fast enough to keep the logical machine operating. Real-time decoding is the layer that receives syndrome data, infers likely errors, updates the Pauli frame or triggers feedback, and prevents the quantum system from becoming limited by classical backlog. Its importance is therefore not merely technical. It determines logical clock speed, system architecture, hardware cost, control-stack integration and the credibility of future claims about scalable quantum computation. The decoder is the classical computer hidden inside the quantum computer.