Quantum technologies are expected to revolutionise many aspects of our lives from computers to communication networks. However, due to exponential scaling of the Hilbert space the behaviour of a general quantum system can only be simulated classically for small system sizes. To go beyond small systems, as suggested by Richard Feynman, the only solution is to use one quantum system to simulate another. In fact, one of the near-term developments of quantum technologies is “quantum simulators” which are already available in various physical systems, including , ultra-cold atoms, trapped ions, superconducting qubits and dopants in silicon. A quantum simulator is a group of quantum particles with highly tuneable interactions which can be used to emulate another quantum system with greater complexity and less controllability. In our group, we are focused on two different approaches: (i) Certification of quantum simulators as neither classical simulation nor quantum state tomography can verify the validity of their outcomes; (ii) Finding new applications for near-term noisy quantum simulators for which the error correction is still not available.