Gaia Coordination Unit 5 (CU5) is the team responsible for calibrating the photometry and low-resolution spectroscopy coming from the European Space Agency’s Gaia spacecraft. It is a group of more than 60 people from all over Europe working on this particular segment of the Gaia data. The CU5 centre, also known as the Data Processing Centre at the Institute of Astronomy (DPCI), is located in Cambridge, UK. The procedure of calibrating the photometry and spectroscopy for approximately two billion sources observed by Gaia spacecraft is complex and iterative. The pipeline requires extensive validation and inspection of the intermediate and final results in order to ensure the quality of the final catalogues, published as Gaia Data Releases. The applicant will be embedded in the DPCI CU5 team, where he will contribute to the tasks related to the validation of the outputs of the calibration procedures, identification of the non-nominal situations, recommendations of the strategies to improve the results and implementation of the improved procedures where necessary.