Foundations of computer science

Time

31–40 weeks

Leads to

Every other path

Anyone starting out, or anyone who learnt to code from tutorials and has gaps.

1. Stage 1: Learn to program , 6–8 weeks

   What to learn

   • Variables, conditions and loops
   • Functions
   • Lists and dictionaries
   • Reading error messages
   • Debugging

   Free resources

   • CS50x: Introduction to Computer Science Course, Harvard University
   • The Python Tutorial Docs, Python Software Foundation

   Build: A small command-line program you design yourself, such as an expense tracker that saves to a file.

   Move on when: You can write a 100-line program without following a tutorial.

2. Stage 2: The terminal, Git and Linux , 3–4 weeks

   What to learn

   • Shell commands and pipes
   • Files and permissions
   • Git commits, branches and merges
   • GitHub
   • A code editor

   Free resources

   • The Missing Semester of Your CS Education Course, MIT
   • Pro Git Book, Scott Chacon and Ben Straub
   • The Linux Command Line Book, William Shotts

   Build: Put every program you have written on GitHub, each with a short README.

   Move on when: You can work in the terminal without a mouse and fix a merge conflict.

3. Stage 3: Data structures and algorithms , 8–10 weeks

   What to learn

   • Big-O notation
   • Arrays, linked lists, stacks and queues
   • Hash tables
   • Trees and graphs
   • Sorting, searching and recursion

   Free resources

   • 6.006 Introduction to Algorithms Course, MIT OpenCourseWare
   • Open Data Structures Book, Pat Morin

   Build: Write your own hash table and a graph search (BFS and DFS), with tests.

   Move on when: You can explain why a dictionary lookup is fast and choose the right structure for a problem.

4. Stage 4: How computers and networks work , 8–10 weeks

   What to learn

   • Logic gates to CPU
   • Memory and processes
   • Operating systems
   • TCP/IP, DNS and HTTP
   • Concurrency basics

   Free resources

   • Nand2Tetris Course, Noam Nisan and Shimon Schocken
   • Operating Systems: Three Easy Pieces Book, University of Wisconsin–Madison
   • Computer Networks: A Systems Approach Book, Larry Peterson and Bruce Davie

   Build: A tiny web server written with raw sockets that serves a page to your browser.

   Move on when: You can explain everything that happens between typing a web address and seeing the page.

5. Stage 5: Math and databases , 6–8 weeks

   What to learn

   • Logic and proofs
   • Sets, counting and probability
   • Relational databases
   • SQL queries and joins
   • Designing tables

   Free resources

   • 6.042J Mathematics for Computer Science Course, MIT OpenCourseWare
   • SQLBolt Practice, SQLBolt
   • Intro to Database Systems (CMU 15-445) Course, Carnegie Mellon University

   Build: Design a database for a small library or shop and answer 20 questions about it in SQL.

   Move on when: You can write a query with joins and grouping, and reason about a simple probability.

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