An Introduction to Information Infrastructure II

Editors: Alexander L. Hayes, Erika Lee, Shabnam Kavousian, Matt Hottell

An introduction to the infrastructure that runs our modern digital world. We introduce the technical background for informatics and computer science. This includes workflows and tools to help you be successful across a variety of computing disciplines. We will briefly review some math foundations, and then introduce programming languages, such as using Python for building backend systems. The final project is to build and deploy a full-stack web application.

We value computing as a discipline for everyone. We therefore aim to avoid misconceptions around computing and strive to keep the material as accessible as possible—accessible in terms of content (we will avoid hand-waving away the details as much as possible), and accessible in terms of monetary cost (this book is free to use, available under the terms of a fairly permissive creative commons license, and one of our goals is to eventually make it possible to be successful with this book without even owning a computer).

I211 Summer 2024

Hi friends! 👋

The key components of this class are the (1) lessons, (2) practice sets, and (3) the final project. This course is online and asynchronous, but we will stick fairly close with the schedule illustrated in this diagram:

How to succeed with technology

Imagine this situation: “You want an app that sends 30-second song snippets to your friends”.

Let’s imagine you have ten friends in this scenario. Would you rather: (Case 1) buy ten computers and mash buttons until all ten computers have an app that sends and receives song snippets? Or would you rather: (Case 2) write one program, and tell your friends to download an app?

Think about these cases for more than three seconds, you will likely conclude that case (1) would be extremely inconvenient for everyone. Buying ten computers would be expensive…. Writing custom programs for all ten computers would be time-consuming…. Delivering a computer to each friend would require coordination. Maybe you’re even a forward-thinking individual and realize that if something goes wrong (and our friend Murphy promises that something will go wrong) it could spell disaster. In the best case: there’s a problem on one computer, and your friend can send it back to you for repair; in the worst case you have to start this whole process from scratch. Buying new computers… writing new programs for them… delivering the new computers….

Why are we beleaguering this point? Well, we have some bad news. If you previously learned programming (either through being self-taught, learned during a course, or perhaps picked up from some basics introduced during high school) there’s a good chance that you were taught how to build hardware–not software.

The whole point of software, or “the code we write” is meant to contrast the hardware: or the physical infrastructure responsible for running the code we write. Hardware is typically whatever part is difficult, time-consuming, or expensive to change. Software–by contrast–should be anything that is easy to start and easy to fix. Therefore we’ll adopt a kind of five-point scale for everything we do:

“It works on my machine” is a meme in programming circles. It’s in the middle of our scale because it’s better than nothing: but we should be aiming higher. We’ll only consider things “to work” when we have a safe way to build, test, reproduce, and ship code to the end user. How do we do that? Read onward.