Recall: The Engine Behind Anki
Build the real SM-2 algorithm that powers Anki and Duolingo. Schedule every flashcard by how well you know it, and watch the intervals stretch as you master them.
What you'll be able to build
Build the real SM-2 algorithm that powers Anki and Duolingo. Schedule every flashcard by how well you know it, and watch the intervals stretch as you master them. Along the way you pick up real, transferable Python skills, not just this one project:
- dicts as records / mutable state
- functions that update state in place
- floating-point math with clamping (max/min)
- conditional scheduling logic
- simulating a process over time
- rounding & formatted reporting
A course like this one
Yours is built from your own placement, so module count and depth will differ. This map shows what a intermediate-level Python learner building Recall actually gets.
- Module 1: Values and output5 lessons
Builds the script for your recall.
- Module 2: Collections and data5 lessons
Builds the data flow workflow for your recall.
- Module 3: Branching and state5 lessons
Builds the function that powers your recall.
- Module 4: Functions and tests5 lessons
Builds the reusable module for your recall.
- Module 5: Files, APIs, and persistence5 lessons
Builds the service boundary for your recall.
- Module 6: Packaging and review3 lessons
Builds the release package for your recall.
How the lessons actually work
Every lesson has you predict what a piece of Python code will output before you run it, then run it for real in your browser and fix what you got wrong. Each module ends in a challenge gate with hidden tests, so you can't advance until your code actually works. The course closes with a capstone that assembles everything into Recall, and a runnable proof page tied to your own code.
Common questions
How long does the Recall: The Engine Behind Anki course take?
about 7 hours, across 6 modules and 28 lessons, at roughly 15 minutes per lesson. Your own course may run shorter or longer, since it's sized to your placement result, not a fixed template.
Do I need experience?
Some. This is an intermediate-tier Python project, so it assumes you're comfortable with Python basics and pushes past them.
How much does it cost?
$15 one-time, no subscription. The first module is free, so you can see exactly how the course teaches before you pay for the rest.