Volcanic piglet, or do-it-yourself SQL

Collecting, storing and transforming data — these are the main tasks of a data engineer. In any one 24-hour period, Bumble Business Intelligence unit receives and processes over 30 billion events sent from clients’ devices or application servers. Researching and interpreting all this data are not trivial tasks; sometimes it…

Unidirectional data-flow and the Zen of black box components

This is the third part in a series of articles on Android architecture at Badoo. Here are links to the first two: MVI beyond state reducers Building a system of reactive components with Kotlin Don’t stop at loose coupling It’s pretty much generally recognised that loose coupling is better than tight coupling. If you are…

Bitmap indexes in Go: unbelievable search speed

Foreword My name is Marko and I gave a talk at Gophercon Russia this year about a very interesting kind of indexes called “bitmap indexes”. I wanted to share it with the community, not only in video format, but as an article too. Please enjoy! Additional materials, slides and all…

From zero to Cosmos — Part #2

This is the story of how a small style guide that was first introduced under the radar, became so appreciated by both developers and designers that it made its way to become a complex unification project — a design system called Cosmos. From zero to Cosmos — Part #1 The “Re-Think” project …

MVI in Kotlin Multiplatform — part 1 (1 of 3)

About a year ago I became interested in some new technology: Kotlin Multiplatform. Since then I have been actively experimenting in this area and promoting this technology within our company. One outcome, for example, is our Reaktive library — Reactive extensions for Kotlin Multiplatform. The story continues here: MVI in Kotlin…

Translating Dust templates to JSX

It appeared in the middle of the decade (plagued by the endless JavaScript framework wars), embraced the DOM, shocked everyone by mixing HTML with JavaScript and transformed the web development landscape beyond recognition. All those accomplishments, without even being a framework. Love it or hate it, React…

Add Superpowers to your Appium-Android tests

[Update]: I have now pushed this feature in new appium-espresso-driver upstream and it is available out of the box to everyone! Please refer to this medium blog for the latest happening Over the past few years, Appium has become one of the most widely used mobile automation tools. While there…

Cron in Linux: history, use and structure

There is an age-old classical saying that happy people don’t watch the clock. There weren’t any programmers or Unix operating systems in those pre-civilisation times, but in our day programmers know for sure that cron is watching the clock for them. For me, command-line utilities are both a passion and…

A monolithic architecture for our clients’ hundreds of versions: how we write and support tests

Like any developer, I really enjoy attending conferences and reading articles. It keeps me up-to-date with what’s going on in software development, as well as be in touch with the tech community. So last December when I was invited to speak at the Highload conference — Russia’s largest professional conference…

PHP code static analysis based on the example of PHPStan, Phan and Psalm

As a company Badoo has been around for over 12 years now. We have a lot of PHP code (millions of lines of code) and there are probably still strings of code that we use which were written all 12 years ago. Some of them were written back in the…

Xcode 10.2, macOS Mojave 10.14.4, iOS 12.1 and other betas

New betas are here and these are some of the most important things that I have learned about them. Swift 5 for Xcode 10.2 beta Swift Firstly, the latest Xcode beta is bundled with the following Swift version: Apple Swift version 5.0 (swiftlang-1001.0.45.7 clang-1001.0.37.7) Target: x86_64-apple-darwin18.2.0 ABI version: 0.6 Let’s start with the most exciting news: Swift…

Bundling C library in Swift framework

In 2014 Apple introduced Swift, a new language for developing applications across its ecosystem. As well as offering various new possibilities and features, it also created some new challenges for those wanting to use good old C libraries. In this article, I will describe one common use case which you…

BPF and Go: Modern forms of introspection in Linux

Everyone has their favourite book about magic. For one person it is Tolkien, for another Pratchett, for a third, like me, it is Max Frei. Today I am going to tell you about my favourite IT magic: BPF and the modern infrastructure surrounding it. BPF is currently at the height…

Deep Neural Networks & Image Captioning

Part 1: Helping our users find love on Badoo Badoo is the largest dating network in the world, with over millions users across 190 countries who upload over 10 million photos per day to our platform. These images provide us with a rich data set we can derive a wealth of insights from. Our Data Science team use image…

From zero to Cosmos — Part #1

This is the story of how a small style guide that was first introduced under the radar, became so appreciated by both developers and designers that it eventually became a complex unification project — a design system called Cosmos. As some of you may know, every good story follows a…

Achieving State Of The Art Results In Natural Language Processing

Part 2: ELMo, BERT and MT-DNN In my previous article I covered some of the fundamental concepts in NLP. This time, I will introduce ELMo, BERT and MT-DNN, architectures which leverage these concepts and have recently achieved some State Of The Art (SOTA) results on NLP tasks. Embeddings from Language Models (ELMo) An introduction to ELMo can be found in this…

Split Testing (A/B Testing) with Swift

Nowadays there are a million apps that solve users’ needs, so it is becoming hard to create something new or be better than market competitors. This has led to a situation where a lot of companies and startups are running experiments to find out which features are actually improving their…

Swift Package Manager builds iOS frameworks (Updated. Xcode 10.2 Beta)

(Updated. Xcode 10.2 Beta) Swift Package Manager doesn’t work with iOS. That’s probably all you can say about the current state of SPM, but insomnia forced me to expand on the issue and compile the following essay. TL;DR Yes, you can build iOS frameworks with Swift Package Manager; Yes, you can adjust settings via .xcconfig…

How many people does it take to change a light bulb?

aka API-Centric Development in Non-API Company (Based on a talk by Konstantin Yakushev @ Nordics APIs) The answer is 24, one to hold the light bulb and … Okay, it’s a bad joke, but the number is right and I’ll explain it why later. Today’s topic is how we ended up developing an API-Centric Development environment…

Configuring Jira for your needs

Perfect flow and ideal ticket If you work in an IT company then the likelihood is that your processes are built around Atlassian’s well-known Jira. There are numerous task-trackers available on the market for solving such tasks, including open-source solutions (Trac, Redmine, Bugzilla), but Jira is probably the most widely used. My name is Dmitry…

Reusability as a pattern: from copy-pasting to components

Bumble is developing several applications (i.e: Badoo and Bumble) and each one of them is a separate product with its own features, management, product and engineering teams. However, we all work together in the same office and solve similar problems. Nevertheless, projects have diverged greatly during development. The codebase was…

How to use Composite builds as a replacement of buildSrc in Gradle

Gradle buildSrc approach has become standard for implementing custom plugins, tasks and specifying common configurations (like dependencies list and versions) but has one major flaw — it invalidates a build cache when it is changed. On the other hand, Gradle also provides an alternative composite build approach that lacks this…

Image detection as a service

How we use deep learning and APIs to support our products Across our two apps Badoo and Bumble, we have over millions registered users worldwide uploading millions of photos a day to our platform. These images provide us with a rich data set from which we derive a wealth of insights.

Reaktive binary compatibility: how we achieve it

As part of the Bumble family — the parent company operating Badoo and Bumble apps — one of my main projects was involved in the team that created Reaktive library — reactive extensions on pure Kotlin. Whenever possible, any library must maintain binary compatibility. Whenever various versions of a library…

Reactive selfies with Camera2 API on Android — Part 2

This is part two of an article, where I show how you can use RxJava2 to build logic on top of asynchronous API. I chose Android Camera2 API as an example (and didn’t regret it!). This API is not only asynchronous, but also has hidden distinctive implementation features which are…