The Earth Cloud Aerosol and Radiation Explorer (EarthCARE) mission, implemented by the European Space Agency (ESA) in collaboration with the Japan Aerospace Exploration Agency (JAXA), aims to measure vertical profiles of aerosols, clouds, and precipitation properties, along with radiative fluxes and heating rates. The mission's data will be used to evaluate the representation of these elements in weather forecasting and climate models. The satellite carries four instruments: the Atmospheric LIDar (ATLID), the Cloud Profiling Radar (CPR), the Multi-Spectral Imager (MSI), and the Broadband Radiometer (BBR). The science data from these instruments are processed on the ground, producing calibrated instrument data (level 1) and retrieved geophysical data products (level 2). This paper provides an overview of the data processing chains of ESA and JAXA, explaining the instrument level 1 data products and calibration algorithms, and an overview of the level 2 data products. The processing chains at ESA and JAXA are almost independent, with ESA producing nominal and calibration products at level 1, and both agencies producing level 2 products. The level 2 processing chains use data from multiple instruments and meteorological data from the European Centre for Medium-Range Weather Forecasts (ECMWF) to derive top-of-atmosphere radiances and fluxes, which are compared to measurements from the BBR instrument. The paper also details the processing algorithms for each instrument, including ATLID's crosstalk management and radiometric pre-processing, CPR's Doppler velocity and surface estimation, MSI's flat-fielding and radiometric calibration, and BBR's radiometric corrections and spatial summations. The processing chains are designed to ensure the accuracy and reliability of the data products, which are essential for improving the representation of clouds, aerosols, and precipitation in weather and climate models.The Earth Cloud Aerosol and Radiation Explorer (EarthCARE) mission, implemented by the European Space Agency (ESA) in collaboration with the Japan Aerospace Exploration Agency (JAXA), aims to measure vertical profiles of aerosols, clouds, and precipitation properties, along with radiative fluxes and heating rates. The mission's data will be used to evaluate the representation of these elements in weather forecasting and climate models. The satellite carries four instruments: the Atmospheric LIDar (ATLID), the Cloud Profiling Radar (CPR), the Multi-Spectral Imager (MSI), and the Broadband Radiometer (BBR). The science data from these instruments are processed on the ground, producing calibrated instrument data (level 1) and retrieved geophysical data products (level 2). This paper provides an overview of the data processing chains of ESA and JAXA, explaining the instrument level 1 data products and calibration algorithms, and an overview of the level 2 data products. The processing chains at ESA and JAXA are almost independent, with ESA producing nominal and calibration products at level 1, and both agencies producing level 2 products. The level 2 processing chains use data from multiple instruments and meteorological data from the European Centre for Medium-Range Weather Forecasts (ECMWF) to derive top-of-atmosphere radiances and fluxes, which are compared to measurements from the BBR instrument. The paper also details the processing algorithms for each instrument, including ATLID's crosstalk management and radiometric pre-processing, CPR's Doppler velocity and surface estimation, MSI's flat-fielding and radiometric calibration, and BBR's radiometric corrections and spatial summations. The processing chains are designed to ensure the accuracy and reliability of the data products, which are essential for improving the representation of clouds, aerosols, and precipitation in weather and climate models.