| # | title | topic | type | difficulty |
|---|---|---|---|---|
| 1 | The accidentally quadratic accumulator | Patterns & Performance | Multiple choice | Medium |
| 2 | Kill the O(n²) lookup | Patterns & Performance | Coding | Medium |
| 3 | Plain object or Map? | Patterns & Performance | Multiple choice | Medium |
| 4 | Observer pattern with unsubscribe | Patterns & Performance | Coding | Medium |
| 5 |
| Prototype pattern: share the methods |
| Patterns & Performance |
| Coding |
| Medium |
| 6 | Mixin pattern: compose behaviors | Patterns & Performance | Coding | Medium |