Fun with Learning Technology
LearnCoursesQuestionsTracksToolsNewsExplorePractice
Fun with Learning Technology

A new problem, explained clearly, every day.

Subscribe
Learn
  • Lessons
  • Topics
  • News
  • Tools
  • Courses
  • Career tracks
  • Everything
Site
  • About
  • Contact
  • Support
  • Privacy
  • Terms
Get the daily one

One email per new problem. No spam.

Request a tutorial

Requests shape what gets made next.

© 2026 Fun with Learning TechnologyRSS
170+ free lessons · a new one every day

Crack the coding interview, one lesson a day.

Daily video walkthroughs on Python, LeetCode, SQL and AI — the working code and the intuition behind it. Free to watch, no account needed.

Browse lessonsStart practicing →
  • ✓ 170+ lessons
  • ✓ Updated daily
  • ✓ 100% free — no login

🔥 Trending now

What learners are watching most

6:44Free

2029. Stone Game IX | LeetCode Daily Python Solution (winner decided before move one)

General
6:31Free

Longest Subsequence With Non-Zero Bitwise XOR

General
3:39Free

Building My Own AI Developer Platform — Ep 2: AI architecture

General
4:27Free

Python Lesson 28: The Phone Number Pattern That Breaks match()

Python

📚 Browse by topic

Every lesson, sorted into tracks

6:49Free

Length of Longest Subarray With at Most K Frequency

Hashmap
4:27Free

Python Lesson 28: The Phone Number Pattern That Breaks match()

Python
7:28Free

Longest Substring of One Repeating Character

TreeHard
3:09Free

Lesson 19: The O(N) Way to Compare Row Context vs Group Totals

Sql
4:08Free

Python Lesson 29: parametrize() Turns 1 Test Into 10

Python
3:00Free

Lesson 1: What Is n8n? (Nodes, Triggers & Workflows Explained)

N8n
3:44Free

n8n Lesson 4: Why Does the Output Panel Show Nothing?

N8n
3:17Free

n8n Lesson 5: Why Does This Node Run Three Times, Not Once?

N8n
7:29Free

Maximum Length Substring With Two Occurrences

Tree
3:42Free

SQL Lesson 20: CHAR vs VARCHAR — Which One Should You Use?

Sql
4:00Free

SQL Lesson 21: The One Missing Word That Wipes Your Whole Table

Sql
0:45Free

deepseek-harness — trending on GitHub

General
3:50Free

Python Lesson 30: Why Does print() Stop Working in Production?

Python
4:04Free

SQL Lesson 22: One Line Can Erase Your Whole Table

Sql
6:31Free

Longest Subsequence With Non-Zero Bitwise XOR

General
3:44Free

Why You Freeze in System Design Interviews (And 10 Habits That Fix It)

Dp
4:46Free

Python Lesson 31: Why Does a 200 Status Code Still Break Your Code?

Python
3:02Free

Why Did Pharma Sales Drop in March? Python Project Tutorial

General
4:16Free

Lesson 23: The 4 SQL Constraints That Kill Bad Data at the Source

Sql
6:44Free

2029. Stone Game IX | LeetCode Daily Python Solution (winner decided before move one)

General
1:43Free

A Coder Blocked 1.5M Bot Pages in a Year — Here's How

Tree
3:45Free

Python Lesson 32: The GIL Is Lying to Your Threads

Python
4:17Free

SQL Lesson 24: One Typo Broke 20 Rows (Here's Why)

Sql
5:48Free

1563. Stone Game V | LeetCode Daily Python Solution (the O(n^2) trick with prefix sums)

Dp
4:24Free

Software-Architecture Lesson 1: Software Architecture Lesson 1: One Login Screen, Three Different An

Architecture
3:37Free

Python Lesson 33: Your Scraper Isn't Slow, It's Just Waiting

Python
4:27Free

SQL Lesson 25: Find 1 Row in 1 Million in Just 20 Steps

Sql
6:17Free

Find the Largest Almost Missing Integer

Twopointer
3:51Free

Python Lesson 34: The Six-Hour Hang timeit and cProfile Could've Stopped

Python
3:58Free

SQL Lesson 26: Why Your View Recomputes Every Single Time

Sql
6:30Free

1386. Cinema Seat Allocation | LeetCode Daily Python Solution: 3 fixed blocks, one AND

GraphMedium
4:44Free

Maximum Subarray Sum With Length Divisible by K

General
3:54Free

SQL Lesson 27: One SQL Fix, Live in Five Apps at Once

Sql
4:58Free

Python Lesson 35: The 5-Line Descriptor That Controls Every Dot

Python
4:23Free

3069. Distribute Elements Into Two Arrays I | LeetCode Daily Python Solution (the trick nobody sees)

Greedy
4:22Free

Python Lesson 36: Your Script Broke In Their Email -- pyproject.toml Fixes That

Python
2:54Free

Lesson 28: The Bug That Loses Money — Transactions & ACID Explained

Sql
8:28Free

3116. Kth Smallest Amount With Single Denomination Combination

Binary
2:17Free

Recursion vs Iteration — Kai vs Tek | FLT Debates

Stack
5:32Free

Python Lesson 37: The Install Problem Nobody Warns You About

Python
0:48Free

2026-07-30_sql-lesson-28-transactions-and-acid-properties-short3

Sql
6:25Free

3622. Check Divisibility by Digit Sum and Product

General
3:51Free

Python Lesson 24: Your Decorator Is Silently Deleting Your Function's Identity

Python
3:39Free

Building My Own AI Developer Platform — Ep 2: AI architecture

General
3:39Free

Type 100, Get 160.9 — Build a Unit Converter (Beginner, Web App) in Python Tutorial

General
3:30Free

Lesson 16: Stop Using Subqueries (Try This Pattern Instead)

Sql
4:26Free

Building My Own AI Developer Platform — Ep 1: The idea

General
7:44Free

1140. Stone Game II | LeetCode Daily Python Solution — grab 2 piles now? You still lose

Greedy
2:12Free

State of Coding — Week of Aug 09: One Release Just 32x'd What AI Can Read

General
3:45Free

n8n Lesson 6: The Silent Typo That Breaks Nothing (And Everything)

N8n
5:43Free

Lesson: 5 Rounds, 1 Catch — Why Proxy Fools Everyone in Round 5

Dp
3:58Free

Python Lesson 25: One yield Replaces Two Dunder Methods

Python
5:13Free

Lesson 17: ROW_NUMBER vs RANK vs DENSE_RANK — Which One Breaks Your Logic?

Sql
7:30Free

1510. Stone Game IV | LeetCode Daily Python Solution (The One Line That Flips the Winner)

Tree
5:05Free

One Bucket, 10,000 Keys — The Attack Hiding in O(1)

Hashmap
4:53Free

Python Lesson 26: Why Loops Hide Bugs That map() and filter() Can't

Python
0:51Free

Lesson 18: Stop Grouping! See Previous Rows Without Collapsing Data

Sql
6:13Free

Smallest Missing Integer Greater Than Sequential Prefix Sum

Dp
7:34Free

2026-08-08_find-the-lexicographically-smallest-valid-sequence

Graph
3:11Free

Lesson 15: Breaking the GPS Problem: Matching Coordinates Without Errors

Sql

Reading about code isn't the same as writing it.

Run real mock interviews, get instant feedback, and track your progress — free, no card needed.

Start practicing free →