Engineering manager and developer| Julik Tarkhanov
We get attached to code - sometimes to a fault. Old migrations are exactly that. They’re digital hoarding at its finest, cluttering up your codebase with files that serve absolutely no purpose other than to make you feel like you’re preserving some kind of historical record. But here’s the brutal truth: your old migrations are utterly useless. They’re worse than useless - they’re actively harmful. They’re taking up space, they are confusing (both for you and new developers on the ...| Julik Tarkhanov
Sometimes, after a few pints in a respectable gathering of Rubyists, someone will ask me “what is the most undervalued module in the Ruby standard library?” There are many possible answers, of course, and some favoritism is to be expected. Piotr Szotkowski, who untimely passed away this summer, did a wonderful talk on the topic a wee while back. My personal answer to that question, however, would be Random. To me, Random is a unsung hero of a very large slice of the work we need to do in ...| Julik Tarkhanov
My previous article about timezones turned out to be useful for quite a few folks, which makes me happy. One candle lights another. Ben Sheldon asked about then actually doing something with those converted times. How do you actually send a newsletter every morning on every working day, regardless of what the user’s time zone is? There are a number of approaches to this - once you know the UTC time of the delivery. I will cover a few of them, including the one I prefer. Let’s wind the clo...| Julik Tarkhanov
The recent Ruby Central tragedy has me in shambles, honestly. It cuts deep at the very spot where I am feeling the most insecurity and the most disenfranchisement. The crux of the issue is creative control. Writing software is a creative endeavor, and we are just now barely getting to the understanding that even though free software promises open source, it does not promise open governance or shared ownership. Something made by a person is their creation, and in the world of pervasive corpora...| Julik Tarkhanov
Doing something at a time convenient for the user is a recurring (sic!) challenge with web applications. And the more users you have across a multitude of time zones, the more pressing it becomes to do it well. It is actually not that hard, but it does have a few fiddly bits which can be challenging to put together. So, let’s do some time traveling.| Julik Tarkhanov
On the 30th of August, 2000, a train flew out of the tunnel at a station in Paris, and, without stopping, rolled on through into the tunnel. It was clear that the train was speeding, and speeding severely. Inside the tunnel, the train has derailed with the front cab car turning over. Luckily, there were no fatalities. 24 people were injured. The investigation was able to establish that the train’s speed was above the maximum permitted on that section of track by 20 km/h, if not more. How co...| Julik Tarkhanov
Good ideas are worth disagreeing with. Sean Goedecke posits that organizations implement process to have legibility – a very interesting idea. However, I see it differently. It is not about legibility but it is about perception of legibility. Does the CEO look at burndown charts in your project management tool? Maybe, but highly unlikely. Does the head of product look at the key user flows that are getting implemented? Maybe. Does the EM look at the backlog of technical debt and prioritize ...| Julik Tarkhanov
Hot on the heels of the previous article I was asked about my idea of having co-located CSS. Now is the time to share, so read on!| Julik Tarkhanov
I’ve needed this before - a couple of times. Third time I figured I needed something small, nimble - yet complete. And - at the same time - wondering about how to do it in a very simple manner. I think it worked out great, so let’s dig in. Most UIs will have some form of undo functionality. Now, there are generally two forms of it: undo stacks and version histories. A “version history” is what Photoshop history gives you - the ability to “paint through” to a previous state of the ...| Julik Tarkhanov
Having the same architecture problems over and over does give you perspective. We all love making fun of the enterprise FizzBuzz but there are cases where those Factories, Adapters and Facades are genuinely very useful, and so is dependency injection. Since I had to do dependency injection combined with adapters a wee many times now, it seems like a good idea to share my experience. What I will describe here mostly applies to Ruby, but it mostly applies to the other languages and runtimes too.| Julik Tarkhanov
There is a lot of talk that big-tech companies are willing to pay way more, way up north of the market to the local rates. They all seem similar: Pre-IPO or public Looking for senior software engineers or staff engineers Salary brackets never published, and even recruiters stay fairly tight lipped So-described “transparent” interview process - usually a marathon of systems design, “culture fit” and leetcode-like excercises And yet it seems that it is hard for those firms to acquire ta...| Julik Tarkhanov
A while ago I got really triggered by by the following two tweets - one by Avdi and another by Pete This essay was on my mind - and lying dormant - for a couple of years, but I think it didnt lose its relevance.| Julik Tarkhanov
An interesting twist in my recent usage of SQLite was the fact that I noticed my research scripts and the database intertwine more. SQLite is unique in that it really lives in-process, unlike standalone database servers. There is a feature to that which does not get used very frequently, but can be indispensable in some situations. By the way, the talk about the system that made me me to explore SQLite in anger can now be seen here. Normally it is your Ruby (or Python, or Go, or whatever) pro...| Julik Tarkhanov
In my work I tend to reach for SQLite more and more. The type of work I find it useful for most these days is quickly amalgamating, dissecting, collecting and analyzing large data sets. As I have outlined in my Euruko talk on scheduling, a key element of the project was writing a simulator. That simulator outputs metrics - lots and lots of metrics, which resemble what our APM solution collects. Looking at those metrics makes it possible to plot, dissect and examine the performance of various ...| Julik Tarkhanov
Joke Accounts and the BOFH are Garbage by Aurynn Shaw struck a chord with me back in the day. After all, who wants to exclude people? Who wants to make them feel unwelcome? Having survived some amount of difficult working experiences I have changed my mind on this drastically. The joke accounts are a bitter necessity, and I’ll try to explain why.| Julik Tarkhanov
Well-made software has a lifetime, and the lifetime is finite. However, sometimes software becomes neglected way before its lifetime comes to an end. Not obsoleted, not replaced - just.. neglected. Recently I have decided to resurrect one such piece of software. See, zip_tricks holds a special place in my heart. It was quite difficult to make, tricky, but exceptionally rewarding. It also went through a number of iterations, and working on it taught me a great lot. How short methods are not al...| Julik Tarkhanov
From my other posts it might seem that I am a bit of a React hater - not at all. React and related frameworks have introduced a very powerful concept into the web development field - the concept of materialised trees. In fact, we have been dealing with those in Rails for years now as well. Standard Rails rendering has been a cornerstone of dozens of applications to date, and continues to be so. But once you see “trees everywhere” it is hard not to think about optimising using trees. So le...| Julik Tarkhanov
Feature flags are amazing. No, really, did I tell you that feature flags are amazing? They are. But you might be running a thousand applications. When this kind of complexity gets involved you might need to test combinations of feature flags, sometimes - dozens of those combinations. Exhaustive testing to the rescue!| Julik Tarkhanov
Marco Rogers started a remarkable thread on Mastodon, which absolutely struck it home for me. Teams absolutely do get mired up in complex tooling. They absolutely can be unprepared, and there absolutely is a skew between the newly-minted “frontend” and “backend” ecosystems. I might have a few things to say about this.| Julik Tarkhanov
Feature flags are awesome. But just like user preferences or settings they have the tendency of turning your application into multiple applications, all embedded in one.| Julik Tarkhanov
There is a popular meme that has been going around for years now, This is in fact close to heart for every passionate technologist. Most of use have either been the guy at the desk, or an innocent passer-by willing to enter the conversation. With fairly expected results.| Julik Tarkhanov
Every succesful application evolves. Business logic is often one of the things that evolves the most, but it is customary to have data which changes over time. Sometimes - over months or years. A lot of spots have logic related to “data over time”. For example: you collect payments from users, but some users were not getting charged VAT. Your new users need to get charged VAT, but they will also pay more, but you want to “grandfather” your existing users into a pricing plan where VAT ...| Julik Tarkhanov
It is curious how people tend to bash DDD. I must admit - I never worked in a full-on DDD codebase or on a team that practices it, but looking at the mentioned articles like this one does make me shudder a little. There is little worse than a premature abstraction, and a there is a noticeable jump (or rather: a trough) which goes from abstraction to indirection. I’ve been programming for more than 20 years now - 12 of those professionally (with a little stint in-between) and I also went fro...| Julik Tarkhanov
A list where you can reorder items is one of entrenched widgets in UIs. Everyone knows how they are supposed to work, they are cheap to build, intuitive and handy. The problem is that they often get built wrong (not the “just grab Sortable.js and be done with it”-kind-of-wrong, but the “Sortable.js does not provide good user experience”-kind-of-wrong). I’ve built a couple of these for various projects and I believe there is an approach that works fairly nicely. So let’s build us a...| Julik Tarkhanov
One of the joys of approaching the same problem multiple times is narrowing down on a number of solutions to specific problems which damn work. One of those are idempotency keys - the other are, undoubtedly, rate limiters based on the leaky bucket algorithm. That one algorithm truly blew my mind the first time Wander implemented it back at WeTransfer. Normally when people start out with rate limiting, a naive implementation would look like this: WebRequest.create!(at_time: Time.now) if WebReq...| Julik Tarkhanov
It has recently become a hot topic that junior developers are having difficulties finding a job, even though the market is very hot at the moment. Market for senior talent is, yes, but for juniors - not so much. As a matter of fact it has been flagged that it is harder than ever for a beginner to start a career in software. Multiple causes have been outlined: Companies do not want to invest into talent which is going to demand extreme raises or leave as soon as they make up experience Compani...| Julik Tarkhanov
I’ve already touched on it a bit in the article about doing the scariest thing first – one of the things we managed to do at WeTransfer before I left was implementing proper idempotency keys for our storage management system (called Storm). The resulting gem is called idempo and you use it about like this: config.middleware.insert_after Rack::Head, Idempo, backend: Idempo::RedisBackend.new(Redis.new) It is great and you should try it out. If you are pressed for time, TL;DR: we built a gem...| Julik Tarkhanov
In software we pride ourselves in being “data-informed”, “metrics driven”, and “formally proven” is the highest praise. Few things feel as satisfying as being actually right, with no shadow of a doubt and no way of escape for our opponents. Being tech people, we cling to this idea that “the more correct” idea, or the one which is “objectively right”, should win. Now, do not underestimate this: As long as all we have is opinions, mine is the best. which is “one way to do ...| Julik Tarkhanov
Science establishes concepts that describe nature, and is often able to signal binary answers to questions. “Can acceleration be non-0 when velocity is 0?” “What is the circumference of a circle?” “How many chromosomes does a fruit fly genome contain?” Art, unlike science, speaks to our emotion. Great art is great exactly because - in addition to execution - it stimulates us to imagine something which makes us feel in a certain way. It is about communicating emotion. There is a to...| Julik Tarkhanov
I know the pieces fit, cause I watched them fall apart Kir recently wrote about fragmented prototyping which struck a nerve. I use a very similar approach for gnarly engineering and system design problems, so figured I could share while we are at it. I call it the maximum pain upfront approach. Another name could be do the thing that scares you the most first. It goes roughly like this. When you need to design a system, make an inventory of the tasks/challenges you expect and make a list of t...| Julik Tarkhanov
There recently was an essay by Gergely about incident response, and a related example of “The 5 Whys” questions, which has been mentioned as a good way to do incident retrospectives. I am not a fan of the “5 whys” approach, because I came to believe there is a problem with it in that it overfocuses on one particular path. With just 5 of the “whys” there is only so much you can express that only touches “abstract group output” or “technology”, without getting into the all-t...| Julik Tarkhanov
This article really made me jump out of my seat. The topic of mentoring isn’t covered properly in our industry, and after having some experience in mentoring and being a mentee – both in software and elsewhere – I believe it has to do with the fact that our approach is deeply flawed to begin with. Over the years I had about 6 mentors (or coaches, if you will), and have myself mentored about 10 people. Only once did it end in something completely unintended or dramatic, and when I was th...| Julik Tarkhanov
A few times a year it seems there are lamentations that “a lot of companies want something like Heroku, but on their internal infrastructure”. Kubernetes does provide something vaguely similar, but apparently isn’t there as far as features go. And time and time again there is this assumption that “if only we had internal Heroku” the amount of tantalizing choices that development teams have to make would be less, deployment would be easier, and everybody would be happier for it. The ...| Julik Tarkhanov
Simon Willison has recently touched on the topic of streaming responses - for him it is in Python, and he was collecting experiences people have had for serving them. I’ve done a lion’s share of streaming from Ruby so far, and I believe at the moment WeTransfer is running one of the largest Ruby streaming applications - our download servers. Since a lot of questions rose up I think I will cover them in order, and maybe I could share my perspective on how we deal with certain issues which ...| Julik Tarkhanov
In the Ruby 3 features, a lot of attention went to Ractors - a new parallelism primitive which provides what can best be described as “Web Workers” - separate threads of execution with memory isolation from the spawning thread. However, there was also a release of a seemingly “nerdy” feature which is the FiberScheduler. Ractors still have to prove their own (my dear friend Kir Shatrov has done some exploration into designing a Ractor-based web server) but I would like to highlight tha...| Julik Tarkhanov
A second time I stumble upon a situation where I have a method which takes a block, and runs that block in a certain context. This is the Ruby pattern we are all familiar “with” (pun intended): with_database_connection do |conn| conn.batch_insert(records) end The most familiar usage of this pattern is, of course, with File objects - we enter a block with the opened file, and the open method then ensures that the file gets closed when we exit the block. What I found to be tricky, though, i...| Julik Tarkhanov
The Go programming language is a curious piece of a kit. Unquestionably successful, no doubt about it - and lots of high-profile Rubyists have taken a liking to it or even moved wholesale (and then espoused vibes to the tune of “I am not using a testing library, look why I am morally superior” and “I run 2 servers instead of your 10, look how much better I am”). Personally, I am not fancying Go that much - primarily because of disagreements with some of the Go authors’ attitudes. I ...| Julik Tarkhanov
This post was written by Luca Suriano and myself. Luca deserves most of the credit and has done the bulk of the work on the software mentioned. Special thanks to Jonathan Rochkind who stimulated us to finally share this post by publishing his own research into the matter. We all know how boring it is to sign a big pile of documents. Tax returns anyone? At WeTransfer we need to create signed URLs to files, but fortunately for us, we’re not in the old days of Johannes Gutenberg anymore, as we...| Julik Tarkhanov
We live in interesting times, and it has finally dawned: many software engineers and designers who wanted to work from home are finally able to. And this brings us to the subject how we work as well. A number of years ago it has become fashionable to work off of laptops. It had a large number of advantages, but in the first place it meant the escape from “the beige”. It meant that you no longer had to be at the office to get your job done - and that your hardware could be your own propert...| Julik Tarkhanov
There is an inherent difficulty to maintaining velocity. We always want things more streamlined, more efficient, more lean - sky is the limit, really, if the technical realm of a product is not micromanaged by the higher echelons of the company management, but is upgraded by grassroots effort. A good team of engineers worth their salt will, as wel know, improve and clean the product of must of technical debt - all a good manager has to do, really, is not to impede that process. There is an in...| Julik Tarkhanov
In the brave new world of self-employment one thing I found very important is getting a grip on time. In general, this turns out to be the biggest challenge for me personally - not having kids and no longer living with a partner I have way more free time than is customary for a 40+ year old, and it shows. And it is becoming more important to get a good understanding of both where the time gets spent, and how much of that time is billable. In the past I used to use Noko for time tracking, but ...| Julik Tarkhanov
Eelco recently wrote about using subdomains in Rails, outlining a seemingly neat idea about having them as subdomains in production but using paths in development. It is clever and looks very usable at first sight. It’s also a very bad idea that is likely to get you side effects you really won’t be happy about. I normally don’t do “rebuttal” posts, but in this case — since I have dealt with that problem before — it feels warranted. Without being too lyrical about it, I want to o...| Julik Tarkhanov
A while ago, Simon Willison expressed the idea that SQLite enables a very neat pattern whereby software can carry its datasets in the form of SQLite databases. Such a database is to be used only to read from, and actually presents a very neat, portable, universal data structure for querying a dataset that would otherwise need to be loaded into memory and structured manually. For dynamic and interpreted languages this is actually even more relevant, because loading a sizeable chunk of data fro...| Julik Tarkhanov
Software is a creative endeavor and a craft. And like any creative endeavor and any craft, it is subject to fashions. About a decade ago, one of those fashions was Hexagonal Rails largely inspired by the DDD book, but also by the original Hexagonal Architecture work by Dr. Cockburn. Some of these applications are now up for their Rails upgrade and an “oil change,” and it’s interesting to see them in the wild and how they get perceived through the lens of the years that have gone by sinc...| Julik Tarkhanov
A few months ago my partner-in-love-and-in-crime came with a seemingly innocuous request, which went as follows: We have an event coming up, and I need to send out a press release via email. It’s simple enough - just a couple of images and a few blurbs of text. I can’t seem to be able to make it look good in Gmail nor in Apple Mail. How does one do such a thing? Now, we computer-savvy household members know darn well that HTML email is, on the list of terrible IT things we have to help ot...| Julik Tarkhanov
Since 2021 I have been working at Cheddar Payments, which is a fledgling fintech startup in the UK. It was a substantial change from WeTransfer in terms of the problem domain, but also scale. The scale at a B2C fintech is smaller, but the challenges are, in ways, much harder. And the biggest challenge - engineering-wise - is “data over time”. I’ve learned more about data over time than I would like, and it can be useful to share my experience.| Julik Tarkhanov
A while ago, a prominent Vercel employee (two, actually) posted to the tune of: Developers don’t get CDNs Exhibit A etc. It is often that random tweets somehow get me into a frenzy – somebody is wrong on the internet, yet again. But when I gave this a second thought, I figured that… this statement has more merit than I would have wanted it to have. It has merit because we do not know the very basics of cache control that are necessary (and there are not that many)! It does not have meri...| Julik Tarkhanov
I’ve needed this before - a couple of times, just like that other thing. A situation where I am doing uploads using AJAX - or performing some other long-running frontend tasks, and I don’t want to overwhelm the system with all of them running at the same time. These tasks may be, in turn, triggering other tasks… you know the drill. And yet again, the published implementations such as p-queue and promise-queue-plus and the one described in this blog post left me wondering: why do they ha...| Julik Tarkhanov
The sites which are using Shardine do not only have separate data storage - they all have their own domain names. I frequently need to validate that every site is able to work correctly with the changes I am making. At Cheddar we are also using multiple domains, which is a good security practice due to CORS and CSP. Until recently I didn’t really have a good setup for developing with multiple domains, but that has changed - and the setup I ended up with works really, really well. So, let’...| Julik Tarkhanov
There is a pattern I am very fond of - “one database per tenant” in web applications with multiple, isolated users. Recently, I needed to fix an application I had for a long time where this database-per-tenant multitenancy utterly broke down, because I was doing connection management wrong. Which begat the question: how do you even approach doing it right? And it turns out I was not alone in this. The most popular gem for multitenancy - Apartment - which I have even used in my failed star...| Julik Tarkhanov
The day was nearing to a close. The sun has already set, but that Friday evening in Amsterdam was still warm. Unusually warm, in fact, for those late days in March – as if spring decided to bless my pilgrimage, for that pilgrimage was not jovial. I was sitting at a ramen joint, sipping on the broth. To my left, a blue, crinkled supermarket shopping bag was sitting solemnly, inconspicuously. Inside that bag sat a slightly used Mac Studio, which I have just purchased to be able to edit CSS of...| Julik Tarkhanov