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…

Optimising relational databases with zero downtime

A case study of Badoo’s most loaded database Optimising relational databases is much harder in high-load circumstances: buying an even more powerful hardware is expensive, and one cannot just turn off the app at night to alter the database and migrate data. In this article I would like to tell you how we completely changed the inner structure…

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…

Introduction of View Styles at Bumble

We are the team behind Badoo and Bumble, two of the world’s largest dating and connection applications with millions of users worldwide. To deal with the challenges that arise with such different products we rely on code reusability, and by so avoiding reinventing the wheel we keep our apps stable…

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…

Deep Neural Networks & Image Captioning

Part 2: Using attention networks to improve the quality of image captions In my previous blog, I introduced the concept of combining a CNN with an LSTM to generate a caption of an image, and talked about how we are using this at Badoo to help our users find love. This time, we will explore how the incorporation of attention networks can…

Regex bytecode interpreter: looking for needles in session haystacks

Here at Badoo, 17 billion events, millions of user sessions and a huge number of virtual dates take place every day. Each event is carefully anonymised and stored in relational databases for subsequent analysis using SQL and SQL-like languages. Contemporary distributed databases containing dozens of terabytes of data are a…

Walk or talk at the best QA conferences in 2018

Do you like meeting new people, sharing your knowledge and keeping up-to-date with the latest technology trends? Then you should definitely check your calendar and add there a few upcoming testing events. I started visiting conferences and meetups a few years ago when I was studying at the university. They…

Part 2: Dynamic Delivery in multi-module projects at Bumble

In part 1 of my series of articles, I have already explained to you what Dynamic Delivery is and what API it has. In this article, I describe in detail exactly how I used Dynamic Delivery in our application Bumble and why, in particular, integration was so easy. As a…

Swift 4.1 introduction of compactMap

In functional programming, we have a clear definition for what a flatMap function is supposed to be. The flatMap method takes a list and a transformative function (which expects zero or more values for each transformation), applies the transformative function to each member of the provided list, and produces a…

Working with a cache: problems and solutions

Hello all! My name is Victor Pryazhnikov and I’m part of the server team at Badoo. Our team is developing and supporting internal API for our customers server-side, caching data is something we deal with every day. Here’s an interesting opinion when it comes to programming: “There are only two…

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…

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…

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…

Particle systems: a Christmas story

Christmas has always been one of my favourite times of the year. For me, Christmas is a season that brings so much love, laughter, happiness, and other magical things into our lives. I was born and raised in Spain, more specifically in Tenerife, a sunny subtropical island in the middle…

Mistakes Unity novices make, based on first-hand experience

Hi, all. It’s me again, Ilya Kudinov, QA engineer at Badoo. Today I am not going to talk about testing but about gamedev. No, this isn’t something we do at Badoo; developing computer games is a hobby of mine. Industry professionals, don’t be harsh in your judgement. All the advice…

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…

Features, but faster: the life of an Android developer at Badoo

Practically speaking, my colleagues and I often need to test an idea as fast and as simply as possible. There’s no point spending lots of effort on implementation because we know that if an experiment proves unsuccessful, we are going to jettison the code in question. Here I will be…

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

This is the concluding article in a series of three articles on MVI architectural pattern in Kotlin Multiplatform. In the previous two articles (part 1 and part 2) we reminded ourselves what MVI is, created the Kittens module for loading images of kittens, and integrated it into iOS and Android…

Part 2: Deep Learning for Engineers

Introduction to Transfer Learning In this article, we use the concepts we saw in part 1 article to unleash the power of neural networks and the reason for their current popularity, namely their reusability. We learn how we can (partially) automate the feature engineering part and how this opens a new world of possibilities…

The story of the lost commit: how to solve this mystery

It was already evening by the time the developer contacted me. The deadbeef commit patch had disappeared from the master branch. They showed me the evidence: the output from two commands. The first one was: git show deadbeef This showed changes to the file: let’s call it Page.php. The canBeEdited…

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…

Covering A/B tests with UI tests:

How to avoid getting tangled up in your own code Hi there! My name is Vitaliy Kotov and I spend most of my time working on automated testing issues at Badoo. In this article, I tell you all about how we have organised the UI testing work with our numerous A/B tests, the problems we have had to deal with…

How to move large-scale React UI-components codebase to TypeScript

Hi, my name is Ivan Grekov and I am a frontend developer at Bumble — the parent company operating Badoo and Bumble apps Our frontend team’s main responsibilities are to deliver new user interfaces and support existing ones across our different applications, mostly within Badoo and Bumble websites. At a…