Why I still take some notes by hand

A scan of the page from my notebook where I review some calculus.
My notes on calculating the grad values of nodes farther away from L (located on the far right). I’m quite pleased that I remembered the Chain Rule despite not having done calculus in ages!
Andrej Karpathy.
Andrej Karpathy is a founding member of OpenAI and worked there as a research scientist from 2015 to 2017. He also was Tesla’s director of artificial intelligence from 2017 to 2022.

I’m very, very slowly working my way through the first of Andrej Karpathy’s “Neural Networks: Zero to Hero” video series as part of one of my missions this year — to pick up some AI programming skills.

I’m deliberately moving very, very, slowly because I’m trying to make sure that I’m not missing any key details, and also because it’s a field that I don’t know much about and one that’s dense with branches of math that I haven’t touched in a long time, such as calculus.

Whenever I do this, I use an older method for note-taking, namely an actual paper notebook, and preferably one that’s graph-ruled. Fortunately, the nearby Walmart is a reliable source. The notebooks they carry even look like the notebook that the hacker character Elliot uses in the Mr. Robot TV series, minus the damage incurred from the considerably more dangerous (if fictional) life that he leads:

My notebook.
My notebook.
Elliot’s notebook from “Mr. Robot.”
Elliot’s notebook in Mr. Robot.

For me, taking handwritten notes and working out all the details behind Karpathy’s description of the system that he’s building step by step in his video helps me get a solid understanding of how and why it works. It’s also so much easier to write equations and draw diagrams by hand…

A scan of the page from my notebook where I calculate the gradient of each node in the neural network.
Calculating the gradient of each node in the neural network, which requires performing some basic calculus at each node.

…and of course, if you’re so inclined, you can easily enhance hand-written notes with comics:

Cartoon self-portrait of me exclaiming “I remember!”
My facial expression, upon realizing that I remembered the chain rule and how I could use it to figure out the gradient for each neural network node.

In his videos, Karpathy does his level best to spell out every last little bit about how AI systems work. It’s impressive — he does explain AI programming better than most lecturers I’ve seen or books I’ve read.

But he’s also someone with a bachelor’s degree in computer science and physics, a masters in which he worked on computer simulations, and a PhD from Stanford where his area of study was some mash-up of computer vision and natural language processing. While he says that all you need to understand his video is a “basic knowledge of Python and a vague recollection of calculus from high school,” it’s pretty clear that he operates on a different level than the rest of us.

I have years of Python experience and took university-level calculus, but I still decided to not skip or skim over anything Karpathy covered. I followed the math in his “first principles” review of what a derivative is, and walked through the process of stepping through the neural network he introduced, which is essentially depth-first binary tree traversal. It’s straight from the standard “algorithms and data structures” course from the sophomore year of a computer science degree program, But hey, it never hurts to review stuff to make sure you truly understand it:

A scan of the page from my notebook where I review of the process of building sets of the nodes and edges that define Karpathy’s example neural network.
This page of notes has a step-by-step review of the process of building sets of the nodes and edges that define Karpathy’s example neural network.

I’m thinking of putting out a series of videos to help people who don’t have a computer science and math background understand some of the stuff that Karpathy covers. It’ll be kind of like the help that Homer Simpson could’ve used when trying to understand marketing:

I’ll close with the first video in Karpathy’s series. If you have any questions about it, feel free to ask me — I’ll see if I can help!


Don’t miss out on’s Black Friday sale!

Here’s your chance to learn mobile development where I learned mobile development, and at a sale price!, the premier mobile developer tutorial site, is having a big Black Friday sale until December 2nd, and you don’t want to miss these bargains…

The offering The price You’ll want this if…
Yearly Plan:
A year’s subscription to the site, which gives you access to all the articles.
$99 / year
(It’s normally $20/month; you’ll save over $140)

You want a steady stream of tutorials — each one typically an afternoon’s worth of work — on a wide array of movile development topics: iOS/Swift, Android/Kotlin, Unity, Flutter, and server-side Swift.

If you’re just getting started with mobile development, especially cross-platform mobile development, you’ll find this quite useful.

Beginning iOS & Swift Black Friday Bundle:
5 books: iOS Apprentice, Swift Apprentice, Core Data by Tutorials, Data Structures & Algorithms in Swift, and Living by the Code.
(Normally $270 for all the books)

You’re new to iOS development, Swift, or both, and want a deep dive. We’re talking a solid two or three months of serious learning in these five books — think of this bundle as boot camp for self-starters who want to learn iOS development.

You’ll want this is you’re serious about getting an app in the App Store or landing a job doing native iOS development.

Beginning Android & Kotlin Black Friday Bundle:
5 books: Android Apprentice, Kotlin Apprentice, Saving Data on Android, Data Structures & Algorithms in Kotlin, and Living by the Code.
(Normally $270 for all the books)

You’re new to Android development, Kotlin, or both, and want a deep dive. We’re talking a solid two or three months of serious learning in these five books — think of this bundle as boot camp for self-starters who want to learn Android development.

You’ll want this is you’re serious about getting an app in the Play Store or landing a job doing native Android development.

Advanced iOS & Swift Black Friday Bundle:
10 books: SwiftUI by Tutorials, Combine: Asynchronous Programming with Swift, Catalyst by Tutorials, iOS Test-Driven Development by Tutorials, Machine Learning by Tutorials, Advanced iOS App Architecture, Concurrency by Tutorials, Design Patterns by Tutorials, Metal by Tutorials, and Mastering Git.
(Normally $580 for all the books)

You’ve been doing iOS development for a while and want to take it to the next level. These books will take you four to six months to go through, and by the end, you’ll be an iOS development force to be reckoned with.

Are you angling for a senior developer position doing iOS development? This is for you.

Advanced Android & Kotlin Black Friday Bundle:
Reactive Programming with Kotlin, Kotlin Coroutines by Tutorials, Advanced Android App Architecture, Android Test-Driven Development by Tutorials, and Mastering Git.
(Normally $300 for all the books)

You’ve been doing Android development for a while and want to take it to the next level. These books will take you four to six months to go through, and by the end, you’ll be an Android development force to be reckoned with.

Are you angling for a senior developer position doing Android development? This is for you.

If you don’t want a bundle, the individual books are also available at sale prices. Don’t miss this opportunity — go check out the store and get these bargains before they’re gone!


The “Your first iOS and SwiftUI app” video course — based on my chapters from the “iOS Apprentice” book!

In the next couple of days, the 8th edition of iOS Apprentice — a great book for beginners who want to learn how to write iOS apps — will be available. I learned iOS programming from an earlier version, and fittingly enough, I wrote the first two sections of the upcoming edition.

In my sections, I show you how to write apps using SwiftUI, the new declarative Swift-based way of defining user interfaces for iOS and other Apple operating systems. This required me to not just revise the previous edition, but to rewrite my sections nearly from scratch. It was a lot of work, but it was enjoyable work, and I’m quite pleased with the results.

If you’d like a taste of what my section of the book is like, check out these sample videos from the course called Your first iOS and SwiftUI app. It’s based on some of my chapters from iOS Apprentice, where you learn how to write your first app: a simple game called Bullseye. You can access the whole course with a subscription, which is a worthwhile investment.

And now, the sample videos…

Your First Programming Challenge: Making a Programming To-Do List

The course starts with a challenge: given a description of the game you’re about to develop, make a to-do list of tasks that you, as the programmer, will have to perform in order to have a completed app.

Getting Started with SwiftUI

Now that you’ve go a to-do list, it’s time to build your first Swift and SwiftUI app — an app that displays a button.

Objects, Data and Methods

Now that you’ve created your first app, you’ll need to learn a little programming theory and how it relates to the code behind the app.

Buttons and Actions

At this point, the app displays a button on the screen, but nothing happens when you press it. Let’s fix that.

Swift UI State

State is a key part of programming with SwiftUI. In this section, Ray introduces the concept of state and how it relates to how the SwiftUI draws the user interface.

Solving Code Problems

One of the biggest pitfalls when learning iOS development when something goes wrong. Here’s how you deal with these situations.

Portrait vs Landscape

In this section, you’ll learn about portrait and landscape modes, iDevice screen resolutions, and setting up the app so that it displays its content in landscape mode only.

Swift UI Views

This covers views, which are anything that’s drawn on the screen.

Swift UI Layout

You’ll learn the basic of laying out user interface elements on the app’s screens in this section.

Spacers and Padding

Cluttered interfaces aren’t as usable, so here come spacers and padding to the rescue!

Once again, you can watch the entire course (plus every other course and tutorial at with a subscription, and you can get this tutorial in book form soon when the book i co-wrote — iOS Apprentice, 8th edition — comes out in just a few days!

Current Events Tampa Bay Uncategorized

If you like my “Tampa Bay tech events” posts, you’ll LOVE the mailing list!

If you want to know what’s happening in the Tampa Bay tech scene, or want to know what tech, entrepreneur, or nerd events are happening in and around the Tampa Bay area, it’s easy: just subscribe to the Tampa Bay tech, entrepreneur, and nerd events mailing list!

It’s got the same content as the weekly post here in Global Nerdy, but delivered straight to your inbox! It’s free of charge, “all ham and no spam,” and I don’t sell your email address (I’ll explain why below).

Why do I make these weekly events postings and the mailing list?

According to the 2019 edition of the annual tech talent report [PDF link] put out by CBRE, Tampa is the top small tech talent market in North America. Our tech talent population grew by over 10,000 people — an increase of about 28% — between 2013 and 2018. With techies in leading markets becoming less available or moving to smaller markets or the Sun Belt, our small but scrappy scene is in a position to put the area on the larger tech map — if we’re willing to put in the work.

Doing the work we do for a living is only part of the job. The other part — and it’s a crucial one — is building a lively tech scene that extends beyond office hours. We need to get together, make friends, share ideas, find work, form clubs, start businesses or side hustles, and do all those things ordinary cities into tech powerhouses. I was there when Toronto was a tech backwater in the early 2000s, but by teaming up with other community-minded techies who brought back their experience from working at tech centers during the dot-com bubble, we built it up into one of the top 3 tech cities in North America. I’d like to help to make the same thing happen here.

Hence my weekly “tech events” post, and thanks to a suggestion by Justin Davis, it’s also available as a weekly email digest.

I don’t charge anything for the list, nor will I make money by selling your email addresses. I plan to profit from the list by helping to make Tampa Bay’s tech scene an active, lively, and prosperous one. So please — subscribe to the list, find some events that interest you, go attend them, and go forth and help build the Tampa tech scene!

Subscribe to the mailing list

Subscribing to the list is easy! Just enter the email address where you’d like to receive the weekly list below…

…and then click the button below…


…and that’s it!


I get asked this question two or three times a week

Sometimes, when it comes up in conversation that I know how to program Android and iOS applications, someone will say “Hey, I have an app idea — do you want to make it for me?” That’s why I laughed so hard at the most recent episode of Rick and Morty.

Here’s the opening scene from that episode:

In most cases, I politely demur — I can quite truthfully back out by saying “I’ve already got a lot on my plate right now.” Does this happen to you, and what do you do?


Coming soon…

Cover of “iOS Apprentice, 8th edition”

Take note of the first author in the list!

The early access edition is available now, and the finalized edition is coming out very, very soon. Watch this space!

Current Events Tampa Bay Uncategorized

What’s happening in the Tampa Bay tech/entrepreneur/nerd scene (Week of Monday, November 18, 2019)

Every week, dedicated individuals and organizations in around the Tampa Bay do more than just their “day jobs”. They get involved in events where they share their knowledge, make connections and friends, and gather together to build strong tech, entrepreneur, and nerd communities. That’s why I do this every week: I put together a list of tech, entrepreneur, and nerd events to make sure that they can be found and you can attend them!

Here’s what’s happening in Tampa Bay this week!

This weekly list is posted as a voluntary service to the Tampa tech community. With the notable exceptions of Tampa iOS Meetup and Coders, Creatives and Craft Beer — both of which I run — most of this information comes from, EventBrite, and other local event announcement sites. I can’t guarantee the accuracy of the dates and times listed here; if you want to be absolutely sure that the event you’re interested in is actually taking place, please contact the organizers!

Monday, November 18, 2019

Tuesday, November 19, 2019

Inno on Fire is Tampa Bay Inno’s inaugural awards ceremony recognizing the region’s entrepreneurs, executives, startups and tech businesses that are on fire. The event will feature “networking, tasty bites, cocktails, craft beer and wine, along with the very special announcement of the ‘Inno Blazer,’” where one standout company or individual from each category to be honored as a blazer, which will be announced at the event. Blazers will receive, yes, a red blazer. Tickets are still available at $55.

We’ll be celebrating the individuals, companies and organizations that are driving innovation across a variety of categories, including…

Wednesday, November 20, 2019

At Wednesday’s Tampa QA Meetup, Jeff Fudge of Green Pages Technologies will present DevOps 101, where he’ll answer questions such as: What is DevOps and why does it matter? What problems will DevOps help testers solve? How do I set up CI/CD pipelines for automated tests? What mistakes can I avoid? Why is continuous testing important?

Thursday, November 21, 2019

Thursday’s Women in Technology International meetup’s topic is Your Lion Inside Rewriting the Narrative for Women. This event will feature Kim Faith, an award-winning author, speaker, trainer, coach, and consultant who has worked with over thirty-thousand corporate leaders from companies including Amazon, American Airlines, Boeing, GE, Lockheed Martin and Target.

Friday, November 22, 2019

Do you have an idea you’d like to pursue? Do you want to work with a passionate startup team? Don’t know where to start or who to start with? Startup Weekend Orlando is THE place to look for a team, create a prototype of your idea, validate your business idea, and receive feedback from experienced entrepreneurs, all in one weekend. This is no exaggeration — Orlando teams won the Global Startup Battle across 150 cities and 15,000 participants in 2017 AND 2018. That’s the last 2 years in a row! Help them make it a 3-peat!

Saturday, November 23, 2019

Sunday, November 24, 2019

Do you have an upcoming event that you’d like to see on this list?

If you know of an upcoming event that you think should appear on this list, please let me know!

Join the mailing list!

If you’d like to get this list in your email inbox every week, enter your email address below. You’ll only be emailed once a week, and the email will contain this list, plus links to any interesting news, upcoming events, and tech articles.

Join the Tampa Bay Tech Events list and always be informed of what’s coming up in Tampa Bay!