Julia: A fresh approach to technical computing

You’ve got something running in Julia that’s pretty neat. It glues together some crazy-good libraries like DifferentialEquations and creates a cool output you want to share with the world.

You want normal humans to be able to try out your code from the convenience of a website. So begins your adventure in deploying Julia.

Websites are written in HTML and JavaScript. So you need your Julia functions to be available behind an API that can be called from JavaScript.

I’ll cut to the chase and tell you what we ended up using for saunasim.com, and then go over some things…

I’ve sold Vora.

A little less than 2 years ago, I embarked on the journey of Vora. Operating under my standard strategy of delivering ASAP in order to get feedback, it took a month from the first commit to publishing Vora on the app stores. The thrill of getting those first users was electric. Someone I’ve never even talked to was using my app and liking it. I incessantly logged into the Firebase Console and refreshed the user database. 10 users, 20 users, 50 users. At the time I was freelancing, so I was able to dedicate a good amount…

The idea of Airquill is simple: trade stories with your friends. It’s like writing letters or stories to each other, with the catch being that you must both submit before anything can be viewed.

The webapp is fully functional: airquill.com

I viewed the project as a social experiment. The technical side is simple, your standard CRUD app. But how people respond to a new social dynamic can only be empirically tested, speculation is fine but doesn’t really answer the question.

My goal from the start was to test it in the wild ASAP. Looking back at the git log, the…

Full disclosure: I’m the creator of Vora, a fasting app that turns a small profit.

I’ve seen a million ads for drugs. I’ve seen ads for essential oils, chiropractors, witch doctors, physical therapy, acupuncture, health coaching, yoga, etc.

I’ve never seen an ad encouraging fasting.

Of all the medical cures in the world, fasting is the ancient underdog. There’s no money to be made. Pharmaceuticals will spend millions trying to push a new concoction through the FDA, but they’d never do a study on the merits of fasting. No $.

Fasting works in theory and in practice. The theory checks…

What you’re doing wrong

Water Per Day 🌊

Water is an essential ingredient for our bodies. I strictly adhere to 8.23 glasses of water per day, as this is the amount of water recommended by experts. Sometimes I’m not thirsty and water isn’t appealing, but I persevere and meet the water quotas because I care about my health.

Eating Speed 🚓

I heard that eating slow will make me basically immortal, so I make sure to spend at least 30 minutes per day chewing my lunch. My jaw gets sore and I dread lunchtime lately, but eating slow has so many health benefits including preventing cancer. 😮

Superfoods 🥕

Every software developer has heard it: “How long do you think that will take?” And they are expected to respond with a single duration, to which they will be held accountable. This ignores uncertainty.

For many professions, the uncertainty is small enough that reasonable predictions can be provided. For example, a carpenter might tell you that he’ll take 2 weeks to build a fence. He doesn’t know that exactly, but he’s pretty sure:

Building a fence has small uncertainty. Created with uncertain.io

With this little uncertainty, a single duration suffices.

Let’s look at some software development curves. …

Vora has surpassed 100,000 registered users!

Some other awesome statistics:

  • 52k monthly active users
  • 66k pounds lost ⚖️
  • Nearly 1 million fasts
  • 50k published fasts with 100k “likes” 👍
  • 100k downloads and 1,000 ratings in the Play Store

I also posted Vora on Product Hunt, pitched at a local meetup, and did a fun interview on the “Tomorrow’s Tech” podcast!

I have yet to spend a single dollar on marketing Vora (not that this is optimal), so it’s been fun and surprising to see the progress it’s made.

The pro version of Vora unlocks these cool visualizations

Vora users have lost 12,000 pounds in a little over 2 months using the weight tracking feature of Vora. Vora is primarily a fasting tracker for those practicing fasting-driven diets.

When users have logged some weight data, they can view it in a chart:

Vora users who utilize the weight tracker have lost 3.6 pounds on average and 1.4 pounds per week! This data includes only people who use the weight feature and who have not gained weight. There are many people (like myself) who do IF to maintain or even gain weight, so I’ve filtered those users out.


After 3 years and many hundreds of hours spent on side projects, I’ve earned my first dollar with the pro version of Vora, a fasting tracker available on iOS and Android.

The pro version unlocks the 4 graphs to the right in the image below:

Since yesterday, 12 users have made the $5 purchase to unlock their graphs and to support the future maintenance and development of Vora.

For me, this is one of the most exciting things I’ve seen in my career.

Also, the heatmap is one of the coolest graphs I’ve ever made, so here’s a closeup:

2.5 months ago, on May 19th, I launched Vora on iOS and Android. Vora is a fasting tracker that’s mostly used by those practicing the intermittent fasting diet. Since the launch, 11,000 registered users have logged 41,000 fasts for a total of 100 years of fasting.

My 2 cents on fasting: Modernity has removed stresses on our bodies that our bodies are built for and used to. For example, our bodies are built to be exercised and there are detrimental effects of not being active. Thus, we must consciously choose to exercise for our own health. The same is true…

Mark Halonen

Software Developer

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