🧠

byte-by-byte

A little bit every day. A lot over time.

每天一点,积少成多

15 minutes of tech knowledge, delivered daily — system design, algorithms, soft skills, frontend, and AI. Bilingual Chinese & English.

5 things, every day

Each day you get one bite of each topic. Small enough to read before coffee. Big enough to compound.

🏗️
System Design
3–4 min
Architecture patterns, tradeoffs, and real-world systems — from DNS to distributed databases.
💻
Algorithms
3–4 min
NeetCode 150 problems in Python, taught through pattern recognition. Solve the next one yourself.
🗣️
Soft Skills
2–3 min
Communication, leadership, and decision-making scenarios — STAR method responses with reflection.
🎨
Frontend
2–3 min
Progressive mastery: CSS → JavaScript → React → Next.js → TypeScript. One concept per day.
🤖
AI
2–3 min
Latest AI news + foundational concepts explained clearly. Stay current without the hype.

What Day 1 looks like

Here's the Algorithms section from Day 1. Every lesson uses real-world analogies, step-by-step traces, and ends with a challenge.

💻
Algorithms Day 1 — #217 Contains Duplicate
Pattern: Hash Set · Difficulty: Easy · 3 min

你负责给活动签到。来了100个人,你需要确认有没有人用同一张票进场两次。

You're checking tickets at an event. 100 people arrive — you need to detect if anyone uses the same ticket twice.

方案A(笨方法):每来一个人,翻遍之前所有人的名单。100×100=10,000次。
方案B(聪明方法):准备一本空白通讯录。每来一个人,查一下——没有就登记,有就报警!

Approach A (Brute Force): For each person, scan all prior names. 100×100 = 10,000 checks.
Approach B (Smart): Keep an empty notebook. For each person — if not seen, record; if seen, alert!

方案B 用的就是今天的核心数据结构:哈希集合 (Hash Set)

def containsDuplicate(nums: list[int]) -> bool:
    seen = set()              # Our "notebook" — starts empty
    for num in nums:
        if num in seen:       # Already stamped this ticket?
            return True        # Duplicate found!
        seen.add(num)         # First time — stamp and record
    return False              # No duplicates
Step-by-step trace with [1, 2, 3, 1]:
Step 1: num=1, seen={} → not found → seen={1}
Step 2: num=2, seen={1} → not found → seen={1,2}
Step 3: num=3, seen={1,2} → not found → seen={1,2,3}
Step 4: num=1, seen={1,2,3} → FOUND! ✅ return True

📂 Browse the full archive for past days with all 5 sections.


How we teach

🎯
Teach, don't lecture
Real-world analogies and "guess the output" challenges — not walls of theory.
🔍
Pattern recognition
We don't just solve problems — we teach patterns so you can solve any problem.
🌏
Natively bilingual
Chinese and English — not translated, but written for both audiences simultaneously.
📈
Builds on itself
Each day references prior lessons. After 30 days, the concepts connect.
Quality-checked
Every lesson goes through self-review and automated QA before delivery.

Get it every day

Two ways to receive your daily byte. All free, all open-source.


Run it yourself

Requires OpenClaw. Takes ~5 minutes to set up. Your data, your cron jobs, your inbox.

1

Clone the repo

git clone https://github.com/YushengAuggie/byte-by-byte.git && cd byte-by-byte

2

Configure your settings

Copy config.env.example to config.env and add your email credentials and delivery settings.

3

Run setup

./scripts/setup.sh — creates cron jobs automatically. You're done.

4

Wake up to content

At 8 AM, your agent generates 5 lessons and delivers them. Every. Single. Day.

📖 Full setup guide on GitHub →