ALLEGRO is a detector concept optimised for precision measurements at the electron-positron phase of the Future Circular Collider (FCC-ee) with a noble liquid electromagnetic calorimeter. An extensive R&D program on the high granular noble liquid calorimeter has been launched. The fine segmentation of the calorimeter is realised by the usage of the straight multi-layer electrodes. This proceeding focuses on the introduction to the ALLEGRO concept, the discussion on the design of its calorimeter, as well as relevant measurements and tests performed in the laboratory. Specifically, the results of the simulations and the measurements with the first prototypes of the multi-layer electrodes are compared. The optimisation studies of the mechanical structure of the calorimeter, along with the results of the tests on the absorber prototype will be shown. The status of the preparation for the test-beam prototype module is discussed.