Chilli peppers (Capsicum spp.) are indispensable components of global culinary traditions and serve as important raw materials for diverse processed products. Due to their high moisture content and perishable nature, effective processing strategies are essential to preserve quality, enhance shelf life, and enable value addition. This chapter comprehensively examines traditional and modern processing technologies applied to chilli peppers. Particular emphasis is placed on the fermentation systems, exploring their microbial ecology, metabolic transformations, and implications for flavour development, safety, and functional enhancement. Advancements in drying technologies, cryogenic grinding, controlled fermentation using defined starter cultures, and process optimization approaches such as Response Surface Methodology are discussed in relation to product quality, bioactive retention, and industrial scalability. Furthermore, the chapter outlines the development of value-added chilli products including powders, flakes, pastes, sauces, pigments, oleoresins, and seed-derived products.