In the early days of software development, the process was often sequential and compartmentalized. Developers wrote the code and then handed it off to Quality Assurance (QA) for testing. This model, sometimes referred to as the "waterfall" approach, often led to quality issues and delays as problems were discovered late in the cycle. Enter the concept of Shifting Left – the idea of applying processes and practices earlier in the life cycle.
Understanding DevOps and Shifting Left
DevOps, a combination of "Development" and "Operations", is a set of practices that aims to shorten the system development life cycle and provide continuous delivery with high software quality. Shifting Left is a paradigm shift in DevOps, revolving around the idea of incorporating quality assurance and testing processes much earlier in the development cycle, hence "Left"— as in, to the left on the timeline of a project.