Cirq

Google's framework for building and running quantum circuits, whether you're simulating locally or deploying to actual quantum hardware from Google, IonQ, AQT, or Pasqal. You get the full stack: circuit construction with parameterized gates, exact and noisy simulation, optimization passes, and noise modeling with channels like depolarizing and amplitude damping. The skill covers practical patterns like variational algorithms (VQE, QAOA), parameter sweeps, and the ReCirq experiment framework. Honestly, if you're doing quantum work in Python, this is the main alternative to Qiskit, and it's especially natural if you're targeting Google's processors or need tight integration with their tooling.