Please respond to the following in a substantive post (3–4 paragraphs): · What a

Please respond to the following in a substantive post (3–4 paragraphs):
· What are the stages of the system development life cycle? Which stage is the most critical stage and why do you think so? 
· There are new approaches to building systems, such as rapid application development, agile, DevOps, etc. Choose any one of the approaches and explain the value it contributes to the system development process. Feel free to use industry examples.