When is Credit Card Cash Back Worth its Fee?
I have a credit card that offers cash back on purchases. Credit cards provide a time buffer between when a charge is incurred and when funds leave the checking account paying it off. This helps avoid
Brett Rowberry’s Blog
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Latest posts
Early Read on Kotlin Community
I want to get into the Kotlin community to accelerate my learning. Where should I go? Well, this was handy, https://kotlinlang.org/community/. I went through each of these resources. Unless stated oth
Hello, Kotlin!
We're switching from Clojure to Kotlin at work. Is that good? I don't know yet! Here are some things I love about Clojure: its incredible REPL EDN keywords maps with heterogeneous keys and values
Vertical Tabs in Chrome
I've been using Arc Browser for a long time. Why? Because I love vertical tabs in my browser. They allow me to read more of each tab's title when I have a lot of tabs. What Are Vertical Tabs? Tabs are
Transpose a Matrix in Clojure
Imagine rows of letters, numbers, and Greek letters: [[:a :b] [:1 :2] [:alpha :beta]] Now, you want to transpose them. You started with a vector of vectors. Clojure's map function is pretty amazing
Binary Search in Clojure
I decided to implement linear search before going after binary search. Now, I’m ready! With linear search, we required the elements be sorted. We didn’t require the elements be bounded. In binary search, the inputs must be bounded because we maintain...
Linear Search in Clojure
I consider myself a classically trained computer scientist. However, I don’t regularly practice implementing algorithms at home. I hope to do more of that! At work, I do much higher level things, like partnering with a product manager, establishing a...
Clojure +, +', and unchecked-add
+ In Clojure core there’s a handy function, +. I’ll bet you know what it does: (+ 1 2 3) ;;=> 6 Let’s introduce a handy function as we explore: (defn value-and-type [& args] (map (juxt identity type) args)) Let’s look at the largest supported L...
Clojure Ratios
Computers do math really quickly. Yet, computers struggle with all kinds of things with math. Take, for example, the simple fraction: 2/3. This should be easy to store right? In most languages, it isn’t. We’re going to use 2/3 throughout all our exam...
Repeating Digits in Clojure
My son asked me if I could make the computer double numbers, like 2 4 6 → 22 44 66 I started with a really ugly solution: (map (fn [x] (parse-long (clojure.string/join "" [(str x) (str x)]))) [2 4 6]) ;;=> (22 4...
Sliding Windows in Clojure
I was doing a little Clojure programming and my son asked me if the computer could make it go 1 2 3, 2 3 4, 3 4 5, … I thought, hmm, that’s a sliding window. Here was my first thought: (->> (range 1 4) (map (fn [x] [x (inc x) (inc (inc x))])))...
VS Code: Simple Browser
Updated September 16, 2025 to indicate that Flares have a singleton mode as explained by PEZ. I just learned about Calva Flares. Then I wondered, is there something built into VS Code for viewing webpages? There is! It’s called Simple Browser and was...
Calva Flares
Updated September 16, 2025 after PEZ showed me how to use the sidebar panel. I was playing with some Clojure code in Calva for Visual Studio Code and stumbled onto a feature. In my Primary Side Bar, I have the Calva view. I noticed the Inspector prev...
Sales Promises
Imagine you’re a salesperson for a boutique car manufacturer and you’re having a sales conversation with a new, important customer: Customer: Thanks for seeing me. I’m really looking forward to one of your custom cars!Salesperson: Absolutely. You can...
Understanding Stacks
In computer science, a stack is what you think it is. A pile. There are two important restrictions: Only add to the top Only remove from the top To illustrate, let’s track how we get dressed using a stack. At first, the stack is empty. Let’s add ...
The Assignment Meeting Squeeze
Say you want someone to do a task for you: fill out a questionnaire, sign off on a document, etc. You can ask them, and they may get around to it. Try this next time. Tell them what you need and set up a fallback meeting far enough in the future that...
Date for a Date
Imagine you’re at work and someone asks you when a new project will be done. Perhaps it’s a request for an on the spot estimate. Further, imagine you have little to no idea. I’d like to introduce you to a concept that I thought was entirely ridiculou...
Hacking the Project Management Triangle
Audience If you’re reading this, I assume you’re a software engineering manager. However, the overall content applies to all projects, and the hack applies to all projects in the context of a company. What’s the Project Management Triangle? For the p...
Prepending to Living Agenda Documents
Imagine you have a recurring meeting with an agenda open to contributions by all participants. Many meetings in the workplace are like this: 1:1s Sprint demos Team operational reviews Perhaps the agenda is written in a Google Doc or a Confluence...
Hello, Production!
When coding locally, a "Hello, World!" program demonstrates a functioning development environment. Deploying a minimal app to production ("Hello, Production!") demonstrates that the program runs in its intended environment. To eliminate uncertainty w...