This Chapter reviews the credit assessment methodologies applied to large non-financial corporations. It examines selected ECAIs, IRB models, ICASes of Eurosystem central banks, and Credit Rating Agencies (CRAs) operating in the Italian market. The review highlights the integration of financial and qualitative data, namely governance, market positioning, and strategic outlook. Besides differences in regulatory frameworks, objectives, and target populations, several common practices emerge. These include group-level assessments, sectoral specialization of analysis, monitoring procedures and the integration of hard data with soft information, gathered from the interaction with assessed firms. The analysis also covers recent methodological developments such as the incorporation of ESG factors and the use of artificial intelligence tools, identifying significant differences across rating sources. The regulatory implications of EU initiatives such as the AI Act and ESG disclosure requirements are expected to significantly impact data governance, model transparency, and oversight—especially in systems that rely on expert judgement or hybrid methodologies.