Day 1 · Mon 2026-10-05 · LeetCode FULL
LeetCode baseline: API, entities, submissions, runners, and leaderboard reads
Week 11 trains two designs with one operating spine: admission, isolation, durable work, queue/backpressure, streaming/reconnect, derived state, evals, and recovery.
3contiguous 1-D DP slots
25-35mattempt + follow-up window
Staffinvariant, failure, recovery, metrics
Exact Daily Schedule
No drift: the same six blocks run every day.
| Time | Block | Contract |
|---|---|---|
| 08:50-09:00 | Target | Write one Staff-level invariant and one failure window before reading. |
| 09:00-10:05 | Project design | 25-35m LeetCode blank-page attempt, then Hello Interview LeetCode baseline anchors. |
| 10:05-10:45 | DDIA / source grounding | Map the design to exact DDIA anchors and only direct applied-AI sources. |
| 10:45-10:55 | Spoken close | Record the architecture in English, then say the Chinese invariant aloud. |
| 14:30-16:15 | 1-D DP contiguous block | Three NeetCode slots below; each slot is 25-35 minutes plus follow-up. |
| 20:30-21:15 | Recall / artifact | Run English Senior+/Staff recall and patch the scorecard evidence. |
Canonical Hello Interview Anchors
Direct day-page anchors only. Source titles were verified live before build.
| Canonical anchor | Disposition | Design decision |
|---|---|---|
| Understanding the Problem | FULL required reading | Read the problem as a product contract before naming services. |
| Functional Requirements | FULL required reading | Separate browse, solve, submit, and leaderboard behavior. |
| Non-Functional Requirements | FULL required reading | Turn instant feedback and contest spikes into explicit SLOs. |
| The Set Up | FULL required reading | State assumptions before drawing the architecture. |
| Planning the Approach | FULL required reading | Move from entities to APIs to high-level services. |
| Defining the Core Entities | FULL required reading | Problem, Submission, Attempt, TestCase, Contest, and Leaderboard are distinct records. |
| API or System Interface | FULL required reading | Submission creation is not synchronous code execution. |
| High-Level Design | FULL required reading | Use a runner queue and durable attempt state. |
| Users should be able to view a list of coding problems | FULL required reading | Problem listing is a read path with filters and cacheable metadata. |
| Users should be able to view a given problem and code a solution | FULL required reading | Problem detail and editor state are different latency classes. |
| Users should be able to submit their solution and get instant feedback | FULL required reading | Submission writes enqueue execution and poll or stream results. |
| Users should be able to view a live leaderboard for competitions | FULL required reading | Leaderboard is a derived view from accepted contest submissions. |
Exact DDIA Mapping
Only Ch5, Ch9, and Ch13 sections are in scope.
| Chapter | Exact section | Interview use |
|---|---|---|
| Ch5 | 流经服务的数据流：REST 与 RPC | Submission creation and runner execution are remote calls with uncertain failure semantics. |
| Ch5 | 事件驱动的架构 | A queue decouples API availability from runner capacity. |
Applied AI Source Gate
First-party/original sources appear only when they change a serving, eval, security, or operating decision.
No applied-AI source is introduced today unless it changes a concrete serving, eval, security, or operating decision.
21-Slot 1-D DP Runway
Today is slot 1-3 of 21, contiguous across the week.
| Block | NeetCode problem | Mode | Invariant | 25-35m follow-up | Complexity |
|---|---|---|---|---|---|
| 14:30-15:05 | Climbing Stairs | Warm-up recurrence | dp[i] depends only on i-1 and i-2; compress to two scalars. | Ask for O(1) space and base cases for n=1. | O(n) / O(1) |
| 15:05-15:40 | Min Cost Climbing Stairs | Cost recurrence | State is cheapest cost to stand on each index; answer is min(last two). | Ask why the top has no cost. | O(n) / O(1) |
| 15:40-16:15 | House Robber | Take/skip recurrence | At each house, carry best with and without current adjacent conflict. | Ask for proof that local choice is not greedy. | O(n) / O(1) |
Artifacts And Recall
Use these in the evening block and scorecard.
Required spoken close: explain one invariant, one failure window, one recovery path, and one metric in English. Then restate the same design decision in Chinese without adding new components.
Detailed lecture notes, audio, recall scripts, PDFs, Staff Q&A, and mock packs are archived locally and are intentionally not published on this site.