Linkdump #4

2026-04-15T00:00:00+00:00

Fourth set of links. This one took some time to collect and some links date quickly but I think they're still nice.

Can we have "Public Money, Public Code"?

2026-03-13T00:00:00+00:00

Free Software Foundation Europe is promoting the idea of “Public Money, Public Code</a>”. It is simple: if everyone paid for the software, it should benefit everyone. To enforce it, we need a law that allows spending the taxpayers’ money only on the open-source software.

This post is me trying to understand, how realistic it is to have this law.

Linkdump #3

2026-02-03T00:00:00+00:00

A third collection of interesting links. This one has a big share of posts on how to work as a Software Engineer.

Generating Short URLs One Character at a Time

2025-12-24T00:00:00+00:00

I came up with a non-bad approach for making URL shorteners.

Linkdump #2

2025-12-16T00:00:00+00:00

A second collection of links I found interesting recently. Many of these are stories on how AI can fail, how humans can fail, and how organizations can fail.

Where to Get Custom Emojis for Slack

2025-12-12T00:00:00+00:00

Want to pimp up your Slack with custom emojis? Check out these services.

Blog Updates and Dirty Tricks

2025-12-06T00:00:00+00:00

In this post you’ll find some recent blog updates (boring), dirty tricks to achieve them (interesting), and unreasonable amounts of praise to Zola</a> (deserved). It might be useful if you’re hosting a blog too.

AI Augmented Scala, my Takeaways

2025-12-01T00:00:00+00:00

I have recently attended the “AI Augmented Scala” workshop from VirtusLab</a>.

Short review: great. I was skeptical at first, expecting it to be another evangelism from the church of AI overlords. But, no, they started the talks with pointing out what AI cannot do. This way, they gained my trust and made an impression it's gonna be a no-bullshit workshop. It was indeed.

And they shared ways to make AI more useful.

My takeaways:

Here’s Why You Should Be Blogging

2025-11-21T00:00:00+00:00

If you searched for motivation to start a blog, this post is for you.

Linkdump #1

2025-11-05T00:00:00+00:00

My first attempt to dump many links on you with short comments about why I consider them interesting. This one is mostly about free software and independence from Big Tech.

What to Expect From Linux

2025-10-15T00:00:00+00:00

So, you're considering to start using Linux? Great! Here's what you need to know to understand what's going on.

Migrating to Scala 3

2025-09-26T00:00:00+00:00

Recently I migrated three old services to Scala 3. This post contains many overly specific notes on problems I faced and how to solve them.

Replacing Mocks with In-Memory Implementations in Scala Tests

2025-09-06T00:00:00+00:00

Recently I worked on migrating a service to Scala3 and one of the major blockers for this was the test code using mockito-scala</a> that works only on Scala2. It was possible to use another mocking library but I used this opportunity to replace mocks with in-memory implementations. This post contains notes on how to do that.

Pull Request Self-Evaluation Checklist

2025-09-01T00:00:00+00:00

Here’s a little self-evaluation checklist to add to the pull request template for internal repositories. This way, when you create a pull request, it reminds you about important stuff you might forget.

How To Structure Generators in Scala Property-based Tests

2025-08-05T00:00:00+00:00

With property-based tests, you end up writing many generators for random data. I saw people coming up with different patterns for defining generators and some of them worked better than others. In this post I'll describe what worked best.

How Not to Resize EFI Partition

2025-06-13T00:00:00+00:00

I have a Framework laptop</a> with Fedora Linux</a> and at some point I couldn’t install firmware updates. The error was not enough free space in my 100MB /boot/efi</code> partition so I had to resize it somehow. None of the guides I could find helped me completely so here’s another one. I also wrote down what didn’t work because those parts of existing forum discussions turned out to be most useful for me.



Android Apps I Use
2025-05-07T00:00:00+00:00
Over time, I’ve replaced most my Android utilities with FOSS alternatives. Usually this involved installing several apps that do the same thing and using them in parallel until it’s obvious which one is the best. Here’s the list of such apps so you and future me can benefit from this effort.</p>


Deno is Fine
2025-03-13T00:00:00+00:00
I have migrated one TypeScript application to Deno</a> and I think it is fine. Probably, it doesn’t make much sense to migrate existing applications, but give it a shot when making one from scratch.</p>
More detailed impressions inside.</p>


Computational Optimization at Work 2024
2024-10-09T00:00:00+00:00
I have attended CO@Work 2024</a> at Zuse Institute Berlin. It is a summer school about computational optimization algorithms.</p>
Nearly everyone I met at CO@Work were Masters and PhD students proficient in optimization. However, they were curious about the experience of working in a company. This is weird. There should be more software engineers there because usually it’s them who have to solve optimization problems in practice. Yet, most are unaware of operations research’s existence.</p>
But there are good news! Almost every talk from CO@Work is now on YouTube. They can serve as a good crash course into operations research. In this post, you'll find links to every recording with my personal impressions of the talks.</p>


Software Engineering At Google Book, my Takeaways
2024-07-01T00:00:00+00:00
"Software Engineering At Google"</a> is a long and uneven book. Every chapter is written by a different person and covers a different topic. Some sections are too basic and boring. Some things are too Google-specific, like bragging on how they solve problems they invented for themselves. But also there are things that should be basics but for some reason I haven't seen them anywhere else. In this blog post I list these things.</p>


Delete Your Agenda Slide
2024-06-14T00:00:00+00:00
An easy way to improve your presentation is to delete your “Agenda” slide. You don’t need it. Seriously.</p>


You Should Own a Domain Name
2024-05-13T00:00:00+00:00
Imagine not owning the key to your home. Every time you want to get inside, you ask some other person to unlock the door for you. They do it for free but at any point, they can change their mind and lock you out. Sounds weird, right? Well, with IoT "smart" locks it’s not unrealistic but still weird. And yet we have the same situation on the Internet.</p>


Yes, You Can Use Different Types With the Same Structure
2024-04-17T00:00:00+00:00
This is a story of how we fixed multiple bugs by typing our array indexes.</p>


Finally a Good Feed Reader
2024-04-02T00:00:00+00:00
After the closure of Google Reader, I have spent years searching for a good RSS feed reader. It seems like I’ve found it.</p>


Don't Start With a Skateboard
2024-03-07T00:00:00+00:00
I'm arguing with metaphors again. Do you remember the famous metaphor that when you need a car, instead of building one, you should build a skateboard, then a scooter, a bike, a motorcycle, and only then a car?</p>
This metaphor shows a good idea of getting feedback earlier. It says, don't make all the work with a big-bang release in the end. Instead, start with something simple, a minimum viable product like a skateboard, and release it immediately. Collect feedback and adjust your work accordingly.</p>
There is one flaw, though. Building skateboards is not easy.</p>


Good GRPC GUI Clients
2023-09-24T00:00:00+00:00
Looking for good GUI clients for debugging GRPC endpoints turned out to be surprisingly hard. It took several attempts and many apps checked. But I found some.</p>


ZIO Log Annotations Are Confusing
2023-02-13T00:00:00+00:00
I was working on a logger that writes metrics every time a warning or an error is logged. I tried to provide additional metric tags depending on the log annotations. And it didn't work. I was adding an annotation and I could see its value somewhere deep in the stack trace but the annotations</code> value was empty.</p>
Turned out that ZIO has two log annotation mechanisms that work in parallel.</p>


Tech Stack of the urmaul.com Blog
2022-11-29T00:00:00+00:00
At the time of writing this, urmaul.com is a static blog with privacy-friendly dynamic elements. Everything runs self-hosted on a single virtual server with an automatically updated Linux.</p>
This is a description of every layer with some reasoning and configuration details.</p>


4 Ways to Fail at Measuring Durations
2022-11-18T00:00:00+00:00
This post is a confession about multiple overlapping mistakes we made when trying to measure API request times. These errors went unnoticed for months because wrong statistics still look realistic. Hopefully, this post will help you avoid such fails.</p>


5 Systematic Ways of Coming up With Property-Based Tests
2021-02-10T00:00:00+00:00
This is a cheat sheet based on a great talk "How to specify it! A guide to writing properties of pure functions" by John Hughes</a>. This talk has a lot of information easy to forget so a cheat sheet may help you refreshing memories without watching the whole talk again.</p>


Solution for Hackerrank Problem: Basic Cryptanalysis
2021-01-29T00:00:00+00:00
There's one programming puzzle I solved many years ago but I still remember it because of the unusual solution.
Problem: You have a text encrypted with a simple monoalphabetic substitution cipher. You don't have the key but you have a dictionary. Every word in a text can be found in this dictionary. Find the original text.
It can be solved by dynamically generating regular expressions.</p>


Solution for Project Euler Problem #700: Eulercoin
2021-01-15T00:00:00+00:00
Problem: Imagine a sequence 1504170715041707*n mod 4503599627370517</code> where n</code> is an integer increasing from 1. Find the subsequence of this sequence where every next element is smaller than the previous one.</p>
All the solutions I've read about include brute force calculations. I found a better one, and I can't stop myself from posting it.</p>


Generating CI/CD Pipelines for Microservices With Yeoman
2020-12-17T00:00:00+00:00
TL;DR:</strong> You can create a Yeoman generator for your CI/CD pipelines. It's good, I tried.</p>
Once you start multiplying services, you hit a problem of increased effort spent on non-business logic. With every new application you need to setup all the boilerplate: initial project, dependencies, running tests, building and deploying everything. Most of this things are very similar from project to project but they differ in details so you can copypaste a lot but you need to do it carefully so you don't break a lot of stuff by forgetting to update one line in a copypasted file. This needs a better solution.</p>


A Good Way How to Validate Types in TypeScript
2020-11-18T00:00:00+00:00
TL;DR:</strong> I've created a typescript library fp-ts-type-check</a>. You can use it to validate the structure of data you get from outside of your application.</em></p>
Here's the situation: your typescript application needs to retrieve some object via some API. You make an API request and you get a successful response with some json. Probably it's the data you expect but you can't say for sure. Your actions?</p>


A Story About Rubber Ducks and Functional Programming
2020-07-31T00:00:00+00:00
Once upon a time, I wanted to get a rubber duck. One rubber duck. I spent a lot of time looking for a perfect yellow rubber duck not representing any character and finally, I have found and bought it.</p>
Later I accidentally found a much better rubber duck. I bought it also. That's one more rubber duck than I but I wasn't cruel enough to throw first one away. A big mistake.</p>


Sudoku Solver in Scala Part 3: Generating Cross-Dependent Test Data
2020-04-28T00:00:00+00:00
This is the last part of my learnings during writing a sudoku solver</a>. It's about several iterations of a property-based test refactoring in an attempt to find the best way to generate input data.</p>


Sudoku Solver in Scala Part 2: Functions Compose, Methods Don’t
2020-04-17T00:00:00+00:00
I keep writing about my learnings during writing a sudoku solver</a>. This time we touch solver's logic and I have something to share about making the big functions out of the small ones.</p>


Sudoku Solver in Scala Part 1: Validated Types
2020-04-09T00:00:00+00:00
Sometimes you're trying to solve a puzzle so hard so you have to write a program to solve it. That happened to me with one specific sudoku so I wrote a sudoku solver</a>.</p>
I did some learning during this and I want to share them here. This part is about injecting validation into the type system.</p>


PHP Doesn’t Want You to Do Microservices
2019-09-09T00:00:00+00:00
As a PHP developer, I should probably rejoice when someone's saying "we do microservices in PHP". I don't. I'm fine with PHP and I like microservices but the combination is just bad. PHP is a tool for solving a narrow range of tasks (i.e. making websites) and if you're trying to do something out of this range (i.e. making microservices) — you're gonna have a bad time.</p>
In this post, I tried to collect all microservice-related PHP problems I saw over the years.</p>


Functional FizzBuzz in Scala With Streams and Higher Order Functions
2019-05-09T00:00:00+00:00
I'm currently learning functional programming with scala and as a practice I've implemented FizzBuzz. To be honest, I made three different implementations of FizzBuzz but only the third one is good.</p>
Stream</span>.from(</span>1</span>) #</span> Create</span> infinite </span>lazy</span> stream from </span>1</span></span>
  .map { (_, </span>""</span>) } # convert it to (number, word) tuple</span></span>
  .map { x =></span> if</span> (x._1 %</span> 3</span> ==</span> 0</span>) (x._1, x._2 +</span> "Fizz"</span>)</span> else</span> x } #</span> Add</span> "Fizz"</span> to each 3rd word</span></span>
  .map { x =></span> if</span> (x._1 %</span> 5</span> ==</span> 0</span>) (x._1, x._2 +</span> "Buzz"</span>)</span> else</span> x } #</span> Add</span> "Buzz"</span> to each 5th word</span></span>
  .map { x =></span> if</span> (x._2 !=</span> ""</span>) x._2 </span>else</span> x._1.toString } #</span> Take</span> word or number</span></span>
  .take(</span>30</span>) #</span> Limit</span> stream length</span></span>
  .foreach(println) #</span> Run</span> everything and print results</span></span></code></pre>
It's even much better than usual imperative implementation and here's why.</p>


React Styleguidist Usage Examples in Typescript Files
2019-03-27T00:00:00+00:00
React Styleguidist uses external Markdown files to store usage examples. We wanted to use TypeScript for examples because reasons and we managed to do this with horrible solution. It includes custom webpack loader that parses TypeScript file with regular expressions and converts it to markdown. You could find parts of our code below.</p>


Finding Overlap Among Groups of Date Ranges
2018-01-23T00:00:00+00:00
Imagine you have two groups of date ranges and you want to determine whether they overlap.</p>
Nah, let's make it harder. Imagine you have two groups of include date ranges and two groups of exclude date ranges. Your task is to determine, whether there's a date that is present in both include groups and not present in exclude groups. How to do that?</p>


Running Bash Commands in Parallel
2017-12-05T00:00:00+00:00
Let's imagine you have a script like below and you want to make it faster.</p>
#!/bin/bash</span></span>
</span>
echo</span> "Started at `</span>date</span> +%Y-%m-%d</span>\ </span>%H:%M:%S`"</span></span>
</span>
echo</span> "Starting job 1"</span></span>
sleep</span> 5</span></span>
</span>
echo</span> "Starting job 2"</span></span>
sleep</span> 5</span></span>
</span>
echo</span> "Finished at `</span>date</span> +%Y-%m-%d</span>\ </span>%H:%M:%S`"</span></span></code></pre>
If it's ok to run jobs in parallel, you can easily do it with bash background jobs.</p>


Difference Between Entities and Value Objects From Philosophy Perspective
2017-11-10T00:00:00+00:00
Imagine a wooden ship. It's a quite famous ship - Theseus himself used it to return to Athens from Crete. After that Athenians tried to preserve it by replacing decayed planks with new ones. Many years passed and now we can say for sure that every part of the ship was replaced at least once. Is it still the same ship?…
</p>


3 Ways to Make Your API Slow
2017-10-11T00:00:00+00:00
I had to fix performance issues of one API endpoint. A pretty Symfony endpoint that gathers some data from database, assembling it to some structure and returns it as json.</p>
Performance started being an issue when major part of that "some data" started to be 60000 entities. In worst case response time was almost 20 seconds. "Ok", I thought, "60k is a big enough number to make it slow". But trace showed that retrieving data from DB isn't a slowest part. There were things taking almost 1/3 of request time each. And these things were easy to fix.…
</p>


How to Make Aliases for Symfony Form Fields
2017-10-02T00:00:00+00:00
Imagine you want to rename form parameter but you also want it to accept old parameter name in requests to preserve backwards compatibility. Here's how you do it.…
</p>


Harmful Technical Interview Questions
2016-06-14T00:00:00+00:00
Junior dev's life is hard an full of dangers. You come to technical interview and think "at least I'll learn something new from guys that know it better than me". Well, not really. Threre are some things that are ok in interviews and are totally wrong in real life. Here are some examples.…
</p>


Imagick Resize Filters Comparison
2015-09-11T00:00:00+00:00
So you want to shrink images with PHP and ImageMagick. Here are samples of all filters so you can select the one you like most.</p>


Nicolas Cage as Default Avatar
2015-04-01T00:00:00+00:00
No one asked me about this for months. And now it's done. Gravacage has it's own documented php library</a> and site</a>.</p>


How to Attach Composer to Yii Project
2014-09-29T00:00:00+00:00
Sometimes I'm asked how to do this. It's boring to tell that again and again so here's the instruction.</p>


Why Composer Matters
2014-08-26T00:00:00+00:00
I've heard about composer long before I started using it. I couldn't understand why it's so much cooler than downloading dependencies manually. I couldn't understand why it's worth running composer install</code> after every code fetch.</p>
This article is for guys like me in the past. If you're already using composer you can stop reading.</p>


Font Awesome Icons for Common Buttons
2014-07-07T00:00:00+00:00
Font Awesone is cool but it is sometomes hard to find the icon you really need because you forgot how it's called. And you have to look at every icon to find something you need.</p>
Here's the names of icons for common buttons and operations.…
</p>


Yii 1.1 Does Not Support Object Cloning
2014-06-26T00:00:00+00:00
You better watch out

You better not cry

You better not clone Yii objects

I'm telling you why

Object cloning is coming to town</s> not supported in Yii 1.1</a>.</p>


urmaul/url to Make Urls Absolute and Stuff
2014-06-04T00:00:00+00:00
Copy-pasting two functions between projects is boring so I've created a GIANT COMPOSER PACKAGE</strong> with class with these two functions. It can convert relative urls to absolute and to add get parameters to urls. It's called urmaul/url</a>.</p>


Creating an API Documentation in Swagger Using YAML
2014-06-02T00:00:00+00:00
UPD:</strong> I wrote this for swagger v1.2. Stuff has changed since then. Now swagger supports single-file YAML specifications, so making them is easier now. What a time to be alive!</p>
A few days ago was the first time I created a REST API documentation. This is the report on how I did it.…
</p>


MySQL Formats for Some Data Types
2014-05-23T00:00:00+00:00
Proper mysql column types for things like emails, coorditates, password hashes and stuff like that.</p>


Free Bootstrap Admin Themes
2014-05-22T00:00:00+00:00
You don't really care how admin panel looks like, yeah?</p>
Bootstrap allows you to create not-so-ugly UI elements but you still have to assemble them into templates.</p>
But there's some free admin themes for bootstrap that are already designed.</p>


Inline PDF in HTML Page
2014-05-21T00:00:00+00:00
A piece of PHP code for inserting PDF files into HTML pages.</p>


Cartograpther - a PHP Component to Generate Sitemaps
2014-05-15T00:00:00+00:00
Some info about a good tool for creating sitemap.xml files and some tips about how to use it.</p>


Disabling Autocomplete in HTML Forms
2014-05-13T00:00:00+00:00
Browsers are so smart they are trying to fill forms for you. And sometimes this is bad.</p>