> For the complete documentation index, see [llms.txt](https://cs61b-2.gitbook.io/cs61b-textbook/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://cs61b-2.gitbook.io/cs61b-textbook/27.-software-engineering-i/27.1-introduction-to-software-engineering.md). # 27.1 Introduction to Software Engineering ### Scale CS 61A is an introductory course that focuses on the correctness of a program. CS 61B, however, focuses on *engineering* software projects. These projects are larger but now require decisions between valid options by considering tradeoffs. The choice between using a LinkedList and an ArrayList, for example, is a tradeoff of runtime and implementation decisions. Working on smaller scale projects isn't the same as larger scale projects that place more emphasis on design. These tasks are often ambiguous. In the real world, there are no specs, no hints to guide you through your project; there's also no end date where you can submit your code and be done with it. This lecture features some light theory and then some real-world examples to illustrate these concepts. Project 3 (Build Your Own World) will allow you to embrace the challenge of large scale projects yourself. ### Further Reading Please read **A Philosophy of Software Design Paperback by John Ousterhout** if you are very interested in this topic. --- # Agent Instructions This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com. ## Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter, and the optional `goal` query parameter: ``` GET https://cs61b-2.gitbook.io/cs61b-textbook/27.-software-engineering-i/27.1-introduction-to-software-engineering.md?ask=&goal= ``` `ask` is the immediate question: it should be specific, self-contained, and written in natural language. `goal` is optional and describes the broader end goal you are ultimately trying to accomplish on behalf of the user. GitBook uses it to tailor the answer towards what is most useful for that goal. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.