An efficient readout of the available information is the key ingredient for understanding many-body systems when performing quantum simulations. In quantum systems every extraction of information implies a back action altering the system’s state. The main objective of this proposal is to develop and experimentally apply minimum disturbing and quantum limited probes for many-body quantum systems. We aim at understanding the influence of measurement back action onto many-body systems. We will combine techniques known from the field of ultracold atoms, quantum optics, and biological imaging with our expertise on many-body quantum systems. Ultracold bosonic quantum gases in one-dimensional trapping potentials are used to study fundamental open problems in the realm of quantum many-body systems. The probing is performed in two ways: Interferometric schemes with off-resonant light are used to implement local weak measurements. Out coupling of few atoms allows us to realize weak probing of the quantum system. Both methods will allow for local probing and spatially resolved readout. We will perform benchmarking measurements with many-body systems studying the quantum back action. With the new methods at hand, we will investigate the role of controlled openness for isolated many-body quantum dynamics. Further, our methods will for the first time allow the measurement of a fluctuation-dissipation relation with ultracold atoms. The project is relevant for the Horizon 2020 program as it will offer new possibilities to study large quantum systems which are fundamentally important for future quantum technologies. The insights will be of importance beyond the ultracold atoms community and trigger and enable research also in different fields as for example biological imaging.