- Coding Patterns & Strategy
Before jumping into problems, understand the patterns:
All LeetCode Articles on Coding Patterns Summarized (https://leetcode.com/discuss/interview-question/5366542/all-leetcode-articles-on-coding-patterns-summarized-in-one-page)
Solved All Two Pointers Problems in 100 Days (https://leetcode.com/discuss/study-guide/1688903/Solved-all-two-pointers-problems-in-100-days)
Tree Question Pattern 2023 — Tree Study Guide (https://leetcode.com/discuss/study-guide/2879240/tree-question-pattern-2023-tree-study-guide)
Important and Useful Links from All Over LeetCode (https://leetcode.com/discuss/general-discussion/665604/Important-and-Useful-links-from-all-over-the-LeetCode)
Coding Interview Preparation Problems for Beginners (https://leetcode.com/discuss/interview-question/448284/Coding-Interview-preparation-problems-for-beginners)
- Company-Specific Prep
Google, Meta, Apple, Amazon Senior SDE Preparation (https://leetcode.com/discuss/study-guide/2559798/Google-Meta-Apple-Amazon-Senior-SDE-Preparation)
A Study Guide for Passing the Google Interview (https://leetcode.com/discuss/study-guide/713716/A-study-guide-for-passing-the-Google-interview)
I was solving problems randomly but had no way to track progress by company. So I built a small tool where you can filter problems by company, mark status (todo/solved/revision), and it auto-schedules what to review next. Also added an AI coach that gives hints (not full solutions) — helps me stay honest when I'm stuck. Have added company-wise questions (https://sdevault.onrender.com)
- System Design (HLD)
The general LeetCode docs are great for breadth, but what actually moved the needle for me was working through structured, progressive sheets instead of random docs. The Design Round has curated HLD sheets that go from crash-prep to full coverage — start narrow, expand when ready:
Arch 25 — crash sheet of the highest-frequency systems and reusable patterns to cover first (https://thedesignround.com/system-design/sheets/arch25)
Arch 50 — Arch 25 plus deeper infra, data, reliability, and advanced product systems for SDE2/Senior prep (https://thedesignround.com/system-design/sheets/arch50)
Arch 75 — Arch 50 plus high-signal variants, niche domains, and company-style specialization (https://thedesignround.com/system-design/sheets/arch75)
Arch All — the complete 103-question HLD bank for full coverage and long-term mastery (https://thedesignround.com/system-design/sheets/archAll)
Core Concepts — 33 distributed-systems deep dives to build the underlying intuition (https://thedesignround.com/system-design/core-concepts)
- Machine Coding (LLD)
The machine coding / LLD round caught me off guard the first time — it's a different muscle from DSA, and most prep ignores it. The Design Round has LLD sheets and design-pattern references that map directly to what gets asked:
MaCo 30 — the core 30 machine-coding problems, highest ROI for interviews (https://thedesignround.com/machine-coding/sheets/maco30)
MaCo 60 — MaCo 30 plus extended coverage across all categories (https://thedesignround.com/machine-coding/sheets/maco60)
MaCo All — the complete list of all 103 machine-coding problems (https://thedesignround.com/machine-coding/sheets/macoAll)
Design Patterns — 31 OOP & structural patterns you'll lean on during the round (https://thedesignround.com/machine-coding/design-patterns)
- Cheat Sheets & References
Big-O Cheat Sheet (https://www.bigocheatsheet.com/)
