Explore safety-critical systems and techniques for ensuring their reliability in this 48-minute conference talk from Devoxx Poland 2021. Delve into how laws of physics are applied to guarantee fail-safety, the benefits of using multiple CPUs for defect detection, and the importance of separating less critical tasks. Learn about ensuring communication safety, creating useful and up-to-date documentation, and how programming language choice impacts system safety. Discover if it's possible to formally prove code is free of runtime errors. Gain insights from embedded software developer Maciej Gajdzica, who specializes in safety-critical systems for industries including railway, automotive, and medical.