Around 2 years ago, I had some time on my hands and got really interested into investing and playing with stock market data. After reading way too many books on the subject, I started building my own tools which led me to creating Itako. It’s a portfolio tracking and data visualization software that lets user journal their stock market transactions, and learn about their portfolio performance and diversification. Itako is now in a stable state, with enough features, so I felt like it was a good time to summarize this project. A prototype The very first thing I did was to create a script that could generate random walks to simulate investment returns over time, and return the graph in the CLI. This was fairly simple, and 250 lines of Python later, I could visualize those random walks going up and down. It allowed me to write my Shannon’s demon article, which explains the non-intuitive advantage of diversification and regular re-balancing. Of course, you can’t really go that far with random walks. Soon after this first step was finished, I decided to integrate real data from the stock market. Once my little script was able to fetch stock quotes from an API, I was able to do some fun things like compute the correlations between different tickers, or evaluate different strategies. Edelfelt As I started building more and more stuff, I got tired of playing with a bunch of Python scripts. I decided to consolidate my project in the form of a CLI that would act as a Swiss-army knife for my experiments. I called it Edelfelt. For this iteration, I also switched from Python to Go. Since the project was growing, Go allows me to really easily create robust and maintainable code that I can still painlessly work with years after. Edelfelt was able to read a list of transactions, turn this into a portfolio which is made up of different positions over time. From this portfolio, it generates a graph, but also output metrics such as the portfolio’s Sharpe ratio (basically the return/risk), compounded returns, total returns, and standard deviation. It could quickly be used to get a portfolio correlation matrix (showing if any 2 positions behave similarly), and weights vector (the % each position is taking in your portfolio). Lastly, you could use it to compare the portfolio to a benchmark (like the S&P500 or the 10-year US treasuries) and determine the excess returns from our strategies. Alpha To make this useable by other people I decided to turn this into a web application, named Itako. I decided to re-use Mikochi’s stack, which is Go and Gin for the backend with a Preact frontend. For a database, I decided to go with MySQL, because it is the only major database system that I have never seen catastrophically fail in production. The data visualization got a serious upgrade, thanks to Echarts (which is really awesome). I also decided to use DaisyUI to get some shiny looking CSS. The backend used the previous code from Edelfelt as a module. This avoided me from having to re-develop everything from scratch. The main improvement is that now, we could cache stock prices in our database. I didn’t expect that to be complicated, sadly cache invalidation is a pain. When I had a decent bunch of features to work with, I pushed the application to production and got around a dozen people to try it. People liked the visualizations, but also found a lot of bugs. Most were pretty minor UI issues, but some were more tricky. I hadn’t planned for some situations, like stock splits and delistings. Beta Aside from fixing the bugs noticed during the Alpha testing, the next step was to handle currency conversions. The aim of this was to let people have stocks from different countries in their portfolios. Getting currencies data is relatively simple since there’s a lot of APIs offering that. However, it completely changes how investment returns are calculated. This led me to refactoring Itako’s business logic and completely getting rid of the dependency to Edelfelt. I decided to go a bit more public about the project and made a Reddit post about it. Around 100 users decided to try Itako and I received plenty of feedback. The main point I learned from this was that I needed to focus on making the application a bit easier to use, and give more actionable data. Release To be honest, the project sat abandoned for a long while after this round of Beta testing. Nothing bad about it, I just really had to focus on shipping our Dice’n Goblins in time. After the game release, I manage to find a bit of time to work on Itako again. I shipped quite a few improvements. Users can now use a simplified input form and abstract away handling cash. Those who do not like this can head to their settings and change it back. I also added a bit of polish, and added a much needed rebalancing feature. This feature shows you the output of different rebalancing strategies on your portfolio. Currently, it implements two very common strategies: equal weights and risk parity. Quite recently, Itako removed its “Beta” badge. The project has most of the features I wanted to build when I created it. It feels weird saying it because I spent way too much time on this, but it is finished. If you want to try it out, just head to itako.app. If you have questions, feedback, or encountered any issues while using Itako, don’t hesitate to email me about it.

Kubernetes is not exactly the most fun piece of technology around. Learning it isn’t easy, and learning the surrounding ecosystem is even harder. Even those who have managed to tame it are still afraid of getting paged by an ETCD cluster corruption, a Kubelet certificate expiration, or the DNS breaking down (and somehow, it’s always the DNS). Samuel Sianipar If you’re like me, the thought of making your own orchestrator has crossed your mind a few times. The result would, of course, be a magical piece of technology that is both simple to learn and wouldn’t break down every weekend. Sadly, the task seems daunting. Kubernetes is a multi-million lines of code project which has been worked on for more than a decade. The good thing is someone wrote a book that can serve as a good starting point to explore the idea of building our own container orchestrator. This book is named “Build an Orchestrator in Go”, written by Tim Boring, published by Manning. The tasks The basic unit of our container orchestrator is called a “task”. A task represents a single container. It contains configuration data, like the container’s name, image and exposed ports. Most importantly, it indicates the container state, and so acts as a state machine. The state of a task can be Pending, Scheduled, Running, Completed or Failed. Each task will need to interact with a container runtime, through a client. In the book, we use Docker (aka Moby). The client will get its configuration from the task and then proceed to pull the image, create the container and start it. When it is time to finish the task, it will stop the container and remove it. The workers Above the task, we have workers. Each machine in the cluster runs a worker. Workers expose an API through which they receive commands. Those commands are added to a queue to be processed asynchronously. When the queue gets processed, the worker will start or stop tasks using the container client. In addition to exposing the ability to start and stop tasks, the worker must be able to list all the tasks running on it. This demands keeping a task database in the worker’s memory and updating it every time a task change’s state. The worker also needs to be able to provide information about its resources, like the available CPU and memory. The book suggests reading the /proc Linux file system using goprocinfo, but since I use a Mac, I used gopsutil. The manager On top of our cluster of workers, we have the manager. The manager also exposes an API, which allows us to start, stop, and list tasks on the cluster. Every time we want to create a new task, the manager will call a scheduler component. The scheduler has to list the workers that can accept more tasks, assign them a score by suitability and return the best one. When this is done, the manager will send the work to be done using the worker’s API. In the book, the author also suggests that the manager component should keep track of every tasks state by performing regular health checks. Health checks typically consist of querying an HTTP endpoint (i.e. /ready) and checking if it returns 200. In case a health check fails, the manager asks the worker to restart the task. I’m not sure if I agree with this idea. This could lead to the manager and worker having differing opinions about a task state. It will also cause scaling issues: the manager workload will have to grow linearly as we add tasks, and not just when we add workers. As far as I know, in Kubernetes, Kubelet (the equivalent of the worker here) is responsible for performing health checks. The CLI The last part of the project is to create a CLI to make sure our new orchestrator can be used without having to resort to firing up curl. The CLI needs to implement the following features: start a worker start a manager run a task in the cluster stop a task get the task status get the worker node status Using cobra makes this part fairly straightforward. It lets you create very modern feeling command-line apps, with properly formatted help commands and easy argument parsing. Once this is done, we almost have a fully functional orchestrator. We just need to add authentication. And maybe some kind of DaemonSet implementation would be nice. And a way to handle mounting volumes…

In the past few years, social media use has gained a bad reputation. More or less everyone is now aware that TikTok is ruining your attention span, and Twitter is radicalizing you into extreme ideologies. But, despite its enormous popularity amongst technology enthusiasts, there’s not a lot of attention given to Discord. I personally have been using Discord so much for so long that the majority of my social circle is made of people I met through the platform. I even spent two years of my life helping run the infrastructure behind the most popular Bot available on Discord. In this article, I will try to give my perspective on Discord, why I think it is harmful, and what can we do about it. appshunter.io A tale of two book clubs To explain my point of view about Discord, I will compare the experience between joining a real-life book-club, and one that communicates exclusively through Discord. This example is about books, but the same issues would apply if it was a community talking about investing, knitting, or collecting stamps. As Marshall McLuhan showed last century, examining media should be done independently of their content. In the first scenario, we have Bob. Bob enjoys reading books, which is generally a solitary hobby. To break this solitude, Bob decides to join a book club. This book club reunites twice a month in a library where they talk about a new book each time. In the second scenario, we have Alice. Alice also likes books. Alice also wants to meet fellow book lovers. Being a nerd, Alice decides to join a Discord server. This server does not have fixed meeting times. Most users simply use the text channels to talk about what they are reading anytime during the day. Crumbs of Belongingness In Bob’s book club, a session typically lasts an hour. First, the librarian takes some time to welcome everyone and introduce newcomers. After, that each club member talks about the book they were expected to read. They can talk about what they liked and disliked, how the book made them feel, and the chapters they found particularly noteworthy. Once each member had the time to talk about the book, they vote on the book they are going to read for the next date. After the session is concluded, some members move to the nearest coffeehouse to keep talking. During this session of one hour, Bob spent around one hour socializing. The need for belongingness that drove Bob to join this book club is fully met. On Alice’s side, the server is running 24/7. When she opens the app, even if there are sometimes more than 4000 members of her virtual book club online, most of the time, nobody is talking. If she was to spend an entire hour staring at the server she might witness a dozen or so messages. Those messages may be part of small conversations in which Alice can take part. Sadly, most of the time they will be simple uploads of memes, conversations about books she hasn’t read, or messages that do not convey enough meaning to start a conversation. In one hour of constant Discord use, Alice’s need for socializing has not been met. Susan Q Yin The shop is closed Even if Bob’s library is open every day, the book club is only open for a total of two hours a month. It is enough for Bob. Since the book club fulfills his need, he doesn’t want it to be around for longer. He has not even entertained the thought of joining a second book club, because too many meetings would be overwhelming. For Alice, Discord is always available. No matter if she is at home or away, it is always somewhere in her phone or taskbar. At any moment of the day, she might notice a red circle above the icon. It tells her there are unread messages on Discord. When she notices that, she instinctively stops her current task and opens the app to spend a few minutes checking her messages. Most of the time those messages do not lead to a meaningful conversation. Reading a few messages isn’t enough to meet her need for socialization. So, after having scrolled through the messages, she goes back to waiting for the next notification. Each time she interrupts her current task to check Discord, getting back into the flow can take several minutes or not happen at all. This can easily happen dozens of times a day and cost Alice hundreds of hours each month. Book hopping When Bob gets home, the club only requires him to read the next book. He may also choose to read two books at the same time, one for the book club and one from his personal backlog. But, if he were to keep his efforts to a strict minimum, he would still have things to talk about in the next session. Alice wants to be able to talk with other users about the books they are reading. So she starts reading the books that are trending and get mentionned often. The issue is, Discord’s conversation are instantaneous, and instantaneity compresses time. A book isn’t going to stay popular and relevant for two whole weeks, if it manages to be the thing people talk about for two whole days, it’s already great. Alice might try to purchase and read two to three books a week to keep up with the server rythm. Even if books are not terribly expensive, this can turn a 20 $/month hobby into a 200 $/month hobby. In addition to that, if reading a book takes Alice on average 10 hours, reading 3 books a week would be like adding a part-time job to her schedule. All this, while being constantly interrupted by the need to check if new conversations have been posted to the server. visnu deva Quitting Discord If you are in Alice’s situation, the solution is quite simple: use Discord less, ideally not at all. On my side, I’ve left every server that is not relevant to my current work. I blocked discord.com from the DNS of my coding computer (using NextDNS) and uninstalled the app from my phone. This makes the platform only usable as a direct messaging app, exclusively from my gaming device, which I cannot carry with me. I think many people realize the addictive nature of Discord, yet keep using the application all the time. One common objection to quitting the platform, is that there’s a need for an alternative: maybe we should go back to forums, or IRC, or use Matrix, etc… I don’t think any alternative internet chat platform can solve the problem. The real problem is that we want to be able to talk to people without leaving home, at any time, without any inconvenience. But what we should do is exactly that, leave home and join a real book club, one that is not open 24/7, and one where the members take the time to listen to each other. In the software community, we have also been convinced that every one of our projects needs to be on Discord. Every game needs a server, open-source projects offer support on Discord, and a bunch of AI startups even use it as their main user interface. I even made a server for Dice’n Goblins. I don’t think it’s really that useful. I’m not even sure it’s that convenient. Popular games are not popular because they have big servers, they have big servers because they are popular. Successful open-source projects often don’t even have a server.

Two weeks ago we released Dice’n Goblins, our first game on Steam. This project allowed me to discover and learn a lot of new things about game development and the industry. I will use this blog post to write down what I consider to be the most important lessons from the months spent working on this. The development started around 2 years ago when Daphnée started prototyping a dungeon crawler featuring a goblin protagonist. After a few iterations, the game combat started featuring dice, and then those dice could be used to make combos. In May 2024, the game was baptized Dice’n Goblins, and a Steam page was created featuring some early gameplay screenshots and footage. I joined the project full-time around this period. Almost one year later, after amassing more than 8000 wishlists, the game finally released on Steam on April 4th, 2025. It was received positively by the gaming press, with great reviews from PCGamer and LadiesGamers. It now sits at 92% positive reviews from players on Steam. Building RPGs isn’t easy As you can see from the above timeline, building this game took almost two years and two programmers. This is actually not that long if you consider that other indie RPGs have taken more than 6 years to come out. The main issue with the genre is that you need to create a believable world. In practice, this requires programming many different systems that will interact together to give the impression of a cohesive universe. Every time you add a new system, you need to think about how it will fit all the existing game features. For example, players typically expect an RPG to have a shop system. Of course, this means designing a shop non-player character (or building) and creating a UI that is displayed when you interact with it. But this also means thinking through a lot of other systems: combat needs to be changed to reward the player with gold, every item needs a price tag, chests should sometimes reward the player with gold, etc… Adding too many systems can quickly get into scope creep territory, and make the development exponentially longer. But you can only get away with removing so much until your game stops being an RPG. Making a game without a shop might be acceptable, but the experience still needs to have more features than “walking around and fighting monsters” to feel complete. RPGs are also, by definition, narrative experiences. While some games have managed to get away with procedurally generating 90% of the content, in general, you’ll need to get your hands dirty, write a story, and design a bunch of maps. Creating enough content for a game to fit 12h+ without having the player go through repetitive grind will by itself take a lot of time. Having said all that, I definitely wouldn’t do any other kind of games than RPGs, because this is what I enjoy playing. I don’t think I would be able to nail what makes other genres fun if I don’t play them enough to understand what separates the good from the mediocre. Marketing isn’t that complicated Everyone in the game dev community knows that there are way too many games releasing on Steam. To stand out amongst the 50+ games coming out every day, it’s important not only to have a finished product but also to plan a marketing campaign well in advance. For most people coming from a software engineering background, like me, this can feel extremely daunting. Our education and jobs do not prepare us well for this kind of task. In practice, it’s not that complicated. If your brain is able to provision a Kubernetes cluster, then you are most definitely capable of running a marketing campaign. Like anything else, it’s a skill that you can learn over time by practicing it, and iteratively improving your methods. During the 8 months following the Steam page release, we tried basically everything you can think of as a way to promote the game. Every time something was having a positive impact, we would do it more, and we quickly stopped things with low impact. The most important thing to keep in mind is your target audience. If you know who wants the game of games you’re making, it is very easy to find where they hang out and talk to them. This is however not an easy question to answer for every game. For a long while, we were not sure who would like Dice’n Goblins. Is it people who like Etrian Odyssey? Fans of Dicey Dungeons? Nostalgic players of Paper Mario? For us, the answer was mostly #1, with a bit of #3. Once we figured out what was our target audience, how to communicate with them, and most importantly, had a game that was visually appealing enough, marketing became very straightforward. This is why we really struggled to get our first 1000 wishlists, but getting the last 5000 was actually not that complicated. Publishers aren’t magic At some point, balancing the workload of actually building the game and figuring out how to market it felt too much for a two-person team. We therefore did what many indie studios do, and decided to work with a publisher. We worked with Rogue Duck Interactive, who previously published Dice & Fold, a fairly successful dice roguelike. Without getting too much into details, it didn’t work out as planned and we decided, by mutual agreement, to go back to self-publishing Dice’n Goblins. The issue simply came from the audience question mentioned earlier. Even though Dice & Fold and Dice’n Goblins share some similarities, they target a different audience, which requires a completely different approach to marketing. The lesson learned is that when picking a publisher, the most important thing you can do is to check that their current game catalog really matches the idea you have of your own game. If you’re building a fast-paced FPS, a publisher that only has experience with cozy simulation games will not be able to help you efficiently. In our situation, a publisher with experience in roguelikes and casual strategy games wasn’t a good fit for an RPG. In addition to that, I don’t think the idea of using a publisher to remove marketing toil and focus on making the game is that much of a good idea in the long term. While it definitely helps to remove the pressure from handling social media accounts and ad campaigns, new effort will be required in communicating and negotiating with the publishing team. In the end, the difference between the work saved and the work gained might not have been worth selling a chunk of your game. Conclusion After all this was said and done, one big question I haven’t answered is: would I do it again? The answer is definitely yes. Not only building this game was an extremely satisfying endeavor, but so much has been learned and built while doing it, it would be a shame not to go ahead and do a second one.