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# Developers share the most interesting tech they ever built

**By:** Luis Minvielle

**Published:** July 13, 2023

Most people's first thoughts about [Hacker News](https://news.ycombinator.com/news) revolve around venture capital, stock prices, company valuations, and $1499 dongles. But what if we told you that Hacker News could also be a place for pure, consummate, _wholesome_ content that tackles how tech projects can help surpass everyday pain points?

Yes, this is dead-on: Contrary to popular sentiment, Hacker News isn't always a forum to gag jokes around over employment or to prove [2000s R&B stars](https://blog.jgc.org/2023/07/unfortunately-kelly-rowland-couldnt.html) plain wrong. Occasionally, the community also features honestly good-for-you content — and it can’t go unnoticed. A recent [Ask Hacker News thread](https://news.ycombinator.com/item?id=35729232) about the most intriguing tech that developers had worked on garnered rightful attention because the answers were far off from Series B or Silicon Valley Bank territory — they brought up consequential tech that any developer should peek at.

It's also a reason to smile: In a corner of the online world in which brainpower is king, there's a thread — aptly titled _Ask HN: Most interesting tech you built for just yourself?_— that reminds us of the real impact that technology can have on our lives. So sit back, grab a cup of Java, and let's scroll through some heart-warming and impactful stories of tech for good. These are ten of the most fascinating projects that were featured by developers on the Hacker News thread.

## 1. Sharing a Wi-Fi password with bricks and toys

One of the [most-liked posts](https://news.ycombinator.com/item?id=35729232&p=3#:~:text=We%20recently%20remodelled,a%2037x37%20matrix.) on the thread solved an archetypal digital problem — obnoxious guests requesting the Wi-Fi password seconds after arriving at a party — with a street-smart, mom-and-pop style solution. The developer in question explained how they needed to decorate their walls after remodelling the kitchen and dining room because they looked too empty and barren, almost like a forum thread. Moreover, this developer realised they were tired of constantly repeating the Wi-Fi password whenever they had visitors. In 4 hours, [they built](https://news.ycombinator.com/user?id=glapworth) a QR code in Lego that lets anyone automatically link to the Wi-Fi network. The most wholesome part was that making it with Legos allowed the developer to undertake the project with their kids. Wasn’t “collaborative working” a trend in the post-pandemic world?

## 2. An original approach to supporting a loved one with dementia

Possibly the most-liked post in the thread, this story referred to a distressing situation involving an ageing family member. [According to the poster](https://news.ycombinator.com/item?id=35729232#:~:text=My%20grandmother%20has,parent%20%7C%20next), their grandmother, affected with dementia, called daily at few-minute intervals to her son (the poster’s father), forgetting that she had just called and spoken with him moments before.

Although the parents were incredibly patient, they eventually gave up and left the phone ringing — creating a sentiment of guilt for not putting up the phone. Trying to solve the interminable telephoning and to provide some solace to the lonely grandmother, is why the poster devised a system in which the calls are diverted by rotating the grandmother's relatives to answer her calls: with this system, each relative has 2 hours without receiving a call from the grandmother. Suppose none of them picks up or is unavailable. In that case, the grandmother gets a voice message recorded by the poster’s father telling her they love her and that everything is alright. The response to this story was unanimously optimistic.

This is basically how it works:

- Start: The Granny decides to make a call.
- Next: The call is automatically diverted to the relative whose turn it is to answer (According to a preset rotating schedule).
- Conditional:
- If the relative picks up: They chat with the Granny until she decides to hang up. Return to Start.
- If the relative doesn't pick up within a certain time (let's say 5 rings): Proceed to the next step.
- Next: The call is automatically diverted to a prerecorded voice message from the Granny's son.
- Next: The Granny listens to the recorded message.
- End: After the message, the call ends. Return to Start when Granny decides to call again.

## 3. The late-game-watching dilemma

A [sports fan](https://news.ycombinator.com/item?id=35729232&p=3#:~:text=A%20software%20developer,a%20few%20others.) enjoys watching football (soccer) games in the morning after they take place; they specifically enjoy watching one or two of the most entertaining games of the week. But, so it happens, traditional or social media usually slips a spoiler or two about sports matches. (This writer knows the feeling: He made extraordinary attempts to watch the Champions League 2023 final match hours after it took place, without knowing the result, and he couldn’t avoid the spoilers — out of the blue, a gas service station clerk told the whole lot to him just when he was about to get home to watch it). For this reason, the sports-loving user created [Laterball](https://laterball.com/epl). This web application algorithmically determines the best Premier League and Champions League games of the last seven days without spoilers, so the users can know which ones they should watch. The backend is a [Ktor](https://ktor.io/) server hosted on a Linode instance that extracts certain statistical data from an API. The user also created an associated Twitter bot that occasionally tweets when there is an entertaining and promising game. “Watchability” is the key term here.

## 4. An automated long-distance call

A user lived through what [pop songs](https://www.youtube.com/watch?v=-3b6hDCIeDk) and pre-teen dramas have explained we can’t ever sustain: a long-distance relationship between Peru and Germany, two places with considerably different time zones. The relationship took place during the dark ages of broadband connection, and being together via Skype — even if the other person was asleep — was unreliable since the internet connection jittered and disconnected. If the other person were sleeping, which was rather likely due to the time difference, the poster would rather not call back to not wake up or interrupt each other's moment. For this reason, the user [created a miniature script](https://news.ycombinator.com/item?id=35729232&p=2#:~:text=For%206%20years,happily%20living%20together%20%3A)) that allows you to send a secret word in the chat so that the other person’s Skype would call the counterpart back automatically, making the [long-distance call](https://www.youtube.com/watch?v=owD3d1S0LFg) a sustainable practice. Thanks to this, they kept their relationship healthy and now live happily together and probably browse through Hacker News regularly. Quite a story.

## 5. Aeroplane flying high!

A Hacker News user lives on the flight path of an airport in Toronto. One day, they became intrigued to know what kind of aircraft flew above them, so they [created an app](https://evergreen-labs.com/PlaneAboveMe.html) that listens to the sound of the plane. Once detected and pinned down, it polls the API data by reading the flight information and aircraft data, fulfilling the function of a “[flight announcer](https://news.ycombinator.com/item?id=35729232&p=4#:~:text=billylo%2074%20days,com/PlaneAboveMe.html).” Check [PlaneAboveMe.html](https://evergreen-labs.com/PlaneAboveMe.html) next time you can’t tell a Boeing from a paper plane!

## 6. No one knows me like the (MIDI) piano

If you think MATLAB is hard, try piano and think again. Playing the piano involves a lot of decision-making and discipline; moreover, sheet music is difficult to read for those learning the instrument. So to progress and enjoy this practice, a user [developed an application](https://news.ycombinator.com/item?id=35729232&p=5#:~:text=I%27m%20writing%20my,be%20very%20motivating%20%3A)) that listens to what you play through MIDI. It keeps track of the segments of a piece you are already good at and automatically lets you practice the ones you are still struggling with. Thus, you don't have to play everything from scratch every time you practice; it also optimises your time so that, after weeks or months, you can suddenly play the whole piece without difficulty. This means you’ll have an additional half an hour each day to stop practising the piano cover of Céline Dion’s “My Heart Will Go On” and instead invest that spare time learning how to [master AI prompts](/magazine/216-the-prompt-engineer).

## 7. An intricate supermarket map

After being tired and frustrated by thinking about which way to go to the supermarket to save time, one user [developed an app](https://news.ycombinator.com/item?id=35729232&p=5#:~:text=firechickenbird%2075%20days,travelling%20salesman%20problem) that gives you the fastest route to the grocery store. After a graphical construction of the entire space with nodes representing the shelves with the shopping items, it loads the shopping list and calculates the optimal route from the entrance to the exit. Has this user brought forward a possible solution to the classic [travelling salesman problem](https://en.wikipedia.org/wiki/Travelling_salesman_problem) without claiming a prize for themselves?

## 8. An out-and-out food tracker

One user [developed an app](https://news.ycombinator.com/item?id=35729232&p=5#:~:text=Nothing%20crazy%20but,stored%20in%20InfluxDB.) to track the information about different edible products in grocery stores. It allows scanning a barcode; the app gives you the product info, name, description, nutritional information, prices in all stores and price changes in the last 30 days. It is built with [React Native](https://reactnative.dev/) and [InfluxDB](https://www.influxdata.com/). The scraper collects prices from multiple stores daily and stores them in InfluxDB. If you were ever rambling about inflation, you might want to get in touch.

## 9. Uncle? Grandfather? Great-grandmother?

A family is genuinely interested in genealogical research, so they have a lot of information about their family tree. A member [developed a web app](https://news.ycombinator.com/item?id=35729232&p=6#:~:text=My%20family%20has,verify%20relationships/birthdays!) — fundamentally a Django CRUD app — to create and edit data, acknowledge links and relationships, and show ancestors and descendants of individuals, accompanied by images to enhance the information. They made an amusing feature called “you are my cousin”, where you choose two people from the database and calculate their relationship. Excellent, unless you’re in [Iceland](https://www.smithsonianmag.com/smart-news/some-icelanders-are-accidentally-dating-a-relative-and-now-theres-an-app-for-that-25175819/).

## 10. Optimal university enrolment

_Good Will Hunting_ suggested it, and students around the world confirmed it: Registering for university classes channelises an intolerable pain. There can be no slots for some courses, and students must constantly reload the page to refresh it until the coveted “Register” button finally shows up correctly.

This developer decided to [automate the process with a script](https://news.ycombinator.com/item?id=35729232&p=6#:~:text=Cuando%20estaba%20en,nuestro%20%C3%BAltimo%20a%C3%B1o.) that inputted the course IDs and checked for openings every few minutes. Every time a space became available, it could send out a text through [Twilio](https://www.twilio.com/en-us); it would then update itself to enrol you in the full course. Don’t use it to cop tickets to a sports event, please.

## So, in conclusion (or TL;DR)

Now that you see reckon Hacker News tech is not only doom and gloom, what are you waiting for? Any of these wholesome projects could be a feature that levels up an existing product. Scan for [companies that are hiring developers](https://www.wearedevelopers.com/) where you can leave your mark yourself. Let this Hacker News thread serve as inspiration!



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