This post discusses the approaches AWS employs to ensure system correctness, specifically through formal and semi-formal methods. It highlights some skepticism regarding the actual application of formal proofs in real-world scenarios at Amazon, suggesting they may only exist in niche areas and questioning the effectiveness of Amazon's hiring practices in relation to the theoretical knowledge of candidates. The perspectives shared indicate a disconnect between formal education or knowledge and practical hiring assessments that focus on algorithmic challenges rather than system design principles.