---
title: 'Week 2'
description: 'Windows, search, lists, and the first trees. Build the HyperAuth reverse-design walkthrough.'
sidebar:
  icon: search
---

**August 24–30, 2026.** Add four patterns. Build the HyperAuth reverse-design walkthrough.

## Goals

- [ ] Learn sliding window, binary search, linked lists, and the first trees.
- [ ] Solve 21 A-set problems, timed and out loud.
- [ ] Build the HyperAuth reverse-design walkthrough. Cut it to 10 minutes.
- [ ] Write stories 4 and 5.

## Daily schedule

| Day | Concept — B1 (untimed) | Timed problems — B2 and B-set | Track B — B4 | Behavioral and pipeline — B5 |
|---|---|---|---|---|
| Mon | Sliding window (5 walkthroughs) | Best Time to Buy and Sell Stock, Longest Substring Without Repeating Characters, Longest Repeating Character Replacement (3) + B-set | Read the Ticketmaster breakdown | — |
| Tue | Sliding window, more depth | Permutation in String, Minimum Window Substring, Sliding Window Maximum (3) + B-set | Build the HyperAuth walkthrough, version 1 (30 min) | — |
| Wed | Binary search (5 walkthroughs) | Binary Search, Search a 2D Matrix, Koko Eating Bananas, Search in Rotated Sorted Array, Find Minimum in Rotated Sorted Array (5) + B-set | Cut the walkthrough to 10 minutes. Add one diagram. | — |
| Thu | Linked list (5 walkthroughs) | Reverse Linked List, Merge Two Sorted Lists, Reorder List, Remove Nth Node From End, Linked List Cycle (5) + B-set | System design solo rep 3: the checkpoint drill | Write story 4: a hire that failed |
| Fri | Gate day. Do no new lesson. | 2 random mediums in 40 minutes. | Review the gate result. | Write story 5: onboard 120+ developers |
| Sat | Linked list (hard) and trees (intro) | LRU Cache, Add Two Numbers (2); Invert Binary Tree, Maximum Depth of Binary Tree, Same Tree (3) + B-set | Matrices (3 bonus walkthroughs) | — |

## Daily blocks

Use the same 10-hour day as [Week 1](/schedule/week-1). Keep Sunday off.

## Friday gate

:::warning[Gate]
Solve 2 random mediums in 40 minutes. Pass with 1 clean solve and 1 near solve, each at 7/10 or more. If you do not pass, repeat the week.
:::

## Outputs

- 21 A-set problems, timed.
- About 12 B-set problems.
- The HyperAuth reverse-design walkthrough, built and cut to 10 minutes.
- Stories 4 and 5.