Series: I Tell Huiqi About

1. What is LLVM? I Tell Huiqi About It. Part 2

Jun 20th 202018:45

This is part 2 of 2 of a conversation I had with Huiqi Zhou where I tell her about LLVM and just can't stop talking. In this episode I show some LLVM IR code examples and explain SSA - Static Single Assignment. LLVM is an open source compiler infrastructure / framework. It contains a state of the art C compiler called clang, and if you want to make your own compiler, it can provide you with building blocks that can make your work easier.

Watch “What is LLVM? I Tell Huiqi About It. Part 2”

2. What is LLVM? I Tell Huiqi About It - Part 1

Jun 20th 202017:03

I've been knee deep in LLVM and in this video I talk to Huiqi about it. LLVM is a compiler infrastructure / framework. It contains a core library which you can use to build your own compiler.

Watch “What is LLVM? I Tell Huiqi About It - Part 1”

3. How Strings Actually Work - with guest Huiqi Zhou

Jun 5th 202027:50

In this video with guest Huiqi Zhou I explain how strings actually work. We go over string encodings, unicode, UTF-8, UTF-16, and more using code examples in Node.js.

Watch “How Strings Actually Work - with guest Huiqi Zhou”

4. Deep-Zoom Debugger Demo with Huiqi Zhou

May 16th 202017:47

I demo the deep-zoom debugger to my colleague Huiqi Zhou.

Watch “Deep-Zoom Debugger Demo with Huiqi Zhou”

5. How Databases Work

Sep 16th 202029:58

Huiqi and I use the analogy of a book to explain about how database work. We explore some very interesting data structures and algorithms that are used in the database.

Watch “How Databases Work”

6. How Time Traveling Works

Nov 16th 202031:55

In this video, Huiqi and I talk about the time traveling debugging I've been working on. We plan to explain the architecture and inner workings of the debugger as well as covering some important computer science concepts along the way over a series of episodes.

Watch “How Time Traveling Works”

7. Memory Management with malloc and free

Nov 30th 202032:16

We are with Huiqi again and this video is part 1 of a series where we walk about memory management. In this part, we will talk about how manual memory management is done in the C programming language. In upcoming episodes we'll talk about garbage collection (GC) as well as automatic reference counting (ARC).

Watch “Memory Management with malloc and free”

8. Games and Education

Dec 8th 202024:12

Toby and Huiqi have a conversation about games and education.

Watch “Games and Education”

9. Automatic Reference Counting

Dec 9th 202031:31

Huiqi and Toby talk about Automatic Reference Counting - a system of automatic memory management used by some popular programming languages including Python, Object-C, Swift, Rust, and more.

Watch “Automatic Reference Counting”

10. Garbage Collection with Mark and Sweep

Dec 17th 202024:39

Toby and Huiqi talk about the full garbage collection mechanism that is used in the most popular programming languages like JavaScript, Java, C# and more. We introduce the mark and sweep algorithm. We also compare it to ARC (Automatic Reference Counting) languages like Python, Swift, and Objective-C.

Watch “Garbage Collection with Mark and Sweep”

11. What it's Like to Code with a Time Traveling Debugger

Jan 11th 202147:52

In this video I want to allow Huiqi and you the viewers to experience what it's like to code with a time traveling debugger. We do a medium difficulty challenge from called Add Two Numbers: At the end we also go over how to get setup if you want to take the debugger for a spin yourself. You can find that info at

Watch “What it's Like to Code with a Time Traveling Debugger”

12. Automatic Test Case Simplification Tool

Jan 27th 202123:28

I tell Huiqi about an tool I made to automate the tedious process of a debugging technique called test case simplification (

Watch “Automatic Test Case Simplification Tool”

13. rr and Time-Traveling Debuggers

Mar 10th 202129:00

In this video I tell Huiqi about rr: a report/replay debugger for C and C++. We talk about how record/replay debuggers work using Redux as a starting point.

Watch “rr and Time-Traveling Debuggers”

14. dabeaz's Compilers Course And X86 Registers

Mar 10th 202115:22

In this video I tell Huiqi about David Beazley's "Write a Compiler" course and X86 registers.

Watch “dabeaz's Compilers Course And X86 Registers”

15. Let's Talk About Performance

Apr 21st 202138:37

I tell Huiqi about a performance war story that took place last week.

Watch “Let's Talk About Performance”

16. Learning C/C++ vs Go or Rust

Apr 21st 202106:39

I talk briefly with Huiqi about learning C and C++ vs more modern languages like Go and Rust.

Watch “Learning C/C++ vs Go or Rust”

17. Let's Talk about Performance! (2)

Apr 28th 202116:33

We talk about performance again! We follow up on the previous week's plan to speed up the "recreate" program. Short version: it worked as predicted! Long version: watch the video. The Stackoverflow answer written by Mike Dunlavey that was cited can be found here:

Watch “Let's Talk about Performance! (2)”

18. Python vs C: Side by Side (Plus Macros!)

Apr 28th 202112:02

I rewrote some Python code in C last couple of weeks to improve the performance of the "recreate" program. Here I show a brief side-by-side comparison of the code before and after with Huiqi.

Watch “Python vs C: Side by Side (Plus Macros!)”

19. Reverse Engineering with GDB

May 12th 202129:43

In this video I excitedly tell Huiqi about reverse engineering: my latest obsession.

Watch “Reverse Engineering with GDB”

20. Visual Concepts: Subway Maps and Flight Paths

May 20th 202121:27

I share with Huiqi (and you!) inspirational visualization concepts I learned from the book: Beautify Visualization. The first is a redesign of the NYC subway map called KickMap(, created by Eddie Jabbour. The second is an animated visualization of the flight paths in North America by Aaron Koblin and Valdean Klump for which you can find the video here:

Watch “Visual Concepts: Subway Maps and Flight Paths”

21. Visual Concepts: Social Graphs and Wikipedia Edit Histories

May 20th 202119:28

This is the second episode where I share with Huiqi (and you!) inspiring visualization concepts from the book: Beautiful Visualization. First we talk about Valdis Krebs' social graphs. Then we talk about Martin Wattenberg and Fernanda Viegas' visualization of the edit history of Wikipedia articles:

Watch “Visual Concepts: Social Graphs and Wikipedia Edit Histories”

22. Making a Terminal-Based UI Framework

May 26th 202119:23

I am making a terminal-based UI framework for the time-traveling debugger project. Here I share what I did so far with Huiqi.

Watch “Making a Terminal-Based UI Framework”

23. Law of Leaky Abstractions

Jul 7th 202110:39

Huiqi and I have chat about Joel Spolsky's Law of Leaky Abstractions: We touch on various topics including TCP/IP, SQL, ORMs, frameworks, and more.

Watch “Law of Leaky Abstractions”

24. Real World Leaky Abstractions 1: Kubernetes, ng, and React

Jul 14th 202113:30

In this chat Huiqi and I give some concrete examples of leaky abstractions. In particular, we give examples in Kubernetes/Docker, Angular, and React in which the abstraction failed to hide the details of the implementation.

Watch “Real World Leaky Abstractions 1: Kubernetes, ng, and React”

25. Real World Leaky Abstractions 2: Sharing TypeScript

Jul 14th 202110:52

In this video I share with Huiqi a war story where I try to share TypeScript definitions among 3 projects: a nest.js project, a React-create-app project, and a React Native/Expo project. It is a classic case of a leaky abstraction: where something which seems like it should be straightforward ends up sendings me through a long series of rabbit holes.

Watch “Real World Leaky Abstractions 2: Sharing TypeScript”

26. Real World Leaky Abstractions 3: Python and Having No Time

Jul 14th 202115:05

Huiqi and I continue our journey into the realm of leaky abstractions. This time we give examples of low code/no code tools, i.e. code generators, Python 2's range function, and then talk about the prospect of making choices when one "has no time".

Watch “Real World Leaky Abstractions 3: Python and Having No Time”

27. Can Leaky Abstractions be Solved?

Jul 14th 202108:43

Huiqi asks me a pressing question: what is the solution to the problem of leaky abstractions? Do I have an answer? Watch and find out.

Watch “Can Leaky Abstractions be Solved?”

28. Leaky Abstractions IRL

Aug 4th 202108:34

Even more leaky abstractions talk! This time Huiqi and I give examples of leaky abstractions that happen in real life, as in outside of coding. Enjoy!

Watch “Leaky Abstractions IRL”

29. Thoughts on Ejecting from a Framework

Aug 11th 202107:21

Huiqi and I talk about the notion of ejecting from a framework using React as an example and I express my problems with the concept.

Watch “Thoughts on Ejecting from a Framework”

30. How to Print a Booklet on OSX

Aug 12th 202103:26

I learned how to print a booklet on Mac OSX and happily share it here.

Watch “How to Print a Booklet on OSX”

31. Global vs Local

Aug 12th 202114:38

Huiqi and I analyze the pros and cons of global/centralized control vs local/distributed control in software projects. The discussion was partly a reaction to an argument I had with my coworker. It's a fun discussion for us and it ended with a poignant moment.

Watch “Global vs Local”

32. Time Machine Status Update 3

Aug 26th 202109:16

This is the first status update on the time-travel debugger in a while, and I do it in Huiqi's presence. I made a windowing system on top of a UI framework I call oui. I implemented a tree widget which is now able to display composite data structures like dictionaries and object with the expand and collapse feature.

Watch “Time Machine Status Update 3”

33. Seeing Code As Fractals

Aug 26th 202118:50

I show Huiqi an interesting performance bug and the interesting way I visualized the execution of the code to understand the problem.

Watch “Seeing Code As Fractals”

34. Time Machine Status Update 4

Sep 2nd 202104:40

Another status update for the time-traveling debugger.

Watch “Time Machine Status Update 4”

35. Eureka Moments

Sep 2nd 202111:35

Huiqi and I talk about eureka moments as they are observed in programming, at least in my observations of myself.

Watch “Eureka Moments”

36. How to Code the Mandelbrot Set

Sep 30th 202135:26

The Mandelbrot Set is one of the most incredible things I've ever witnessed in life. This is part 1 of a 2 part series where I share it with Huiqi and you. I give a step by step tutorial for how to create a Mandelbrot Set visualization yourself, using nothing by HTML and JavaScript. Enjoy! If you'd like, the source code produced in the episode can be found at

Watch “How to Code the Mandelbrot Set”

37. GPUs, Shaders and OpenGL

Oct 21st 202132:30

This past week I've gone on an adventure learning OpenGL, WebGL, GLSL and more all in an effort to get a fast Mandelbrot Set render. It's been a ton of fun and I share my experience with Huiqi and you. Here is my repo learn-opengl where I've posted a curated list of learning resources for OpenGL:

Watch “GPUs, Shaders and OpenGL”

38. Is Code Reuse Bad?

Nov 4th 202117:14

This is a conversation between Huiqi and I about the notion I have heard recently from multiple very intelligent people that software reuse is bad, which flies in the face of most current opinion. Here are my sources:

Watch “Is Code Reuse Bad?”