A Custom LayoutManager Case: Bumble Beeline

Task

Mutation Testing in PHP: quality measurement for code coverage

How do you evaluate how good your tests are? Many people rely on the most popular score, the one everyone knows — code coverage. But this is a quantitative, rather than a qualitative metric. It shows how much of your code is covered by the tests, but not how well…

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…

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…

Modularising the Badoo iOS app

In my previous article, I explained how we singled out the chat functionality in our app for modularisation. Everything had gone well and we were preparing to roll out this experience to start work on modularising all of Badoo iOS app development. We even did a presentation on the approach…

Checking your app’s paid services without losing money

Checking paid services is crucial in Badoo and Bumble apps testing process. Our applications are integrated with 70 payment providers in 250 countries. This means that bugs at any integration can seriously affect revenues, and in unpredictable ways. In this article, you will learn about methods that we employ in…

Optical alignment for frontend developers:

How to align elements in user interfaces. Hi, my name is Ivan Grekov and I work in the front-end team at Badoo. My primary responsibilities entail looking after the user interfaces for a variety of projects. More specifically, this involves working with optical alignment of user interfaces. In this article, I’d like to share with you why…

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…

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…

Continuous delivery for your Kotlin Multiplatform library

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 — Reaktive Extensions on pure Kotlin. In the case of Kotlin Multiplatform I discovered that continuous integration and continuous delivery require…

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 2 (2 of 3)

This is the second in a series of three articles on MVI architectural pattern in Kotlin Multiplatform. In the article part 1 we reminded ourselves what MVI is and learned how to use it to write shared code using MVI. We defined simple abstractions like Store and View as well…

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…

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…

Achieving State Of The Art Results In Natural Language Processing:

Part 1: Fundamental Concepts Badoo is the largest dating network in the world, with over millions of registered users worldwide. Users of our site are prompted to write an “About me” section in order to give any prospective love interests a little bit more information about themselves.

Home-grown bytecode interpreters

In recent decades the use of virtual programming language machines has become very widespread. It is some time since the Java Virtual Machine was first launched in the latter half of the 90s, so we can state with confidence that bytecode interpreters are now very much a reality and not…

Reaktive — a multiplatform library for reactive Kotlin

Reactive programming is really popular today not least because it has loads of plus points: the absence of what is called ‘callback hell’; a built-in mechanism for processing errors; and a functional programming style that reduces the likelihood of bugs occurring. It makes it much easier to write multi-threaded code…

Intercepting and redefining modal presentation from a third-party framework

The Problem Some time ago, here at Badoo, we introduced a third-party library to cover our project needs. It was working well, except for one detail: it was presenting UI using iOS modal presentation (typical full screen view controller which is shown from the bottom of the screen), but according to our…

Design Tokens beyond colors, typography, and spacing.

In recent months, I couldn’t help but notice how many people (and companies) when referring to “design tokens” what they actually mean is colors, typography, spacing (and in some cases elevation, timing, and sizing). While this is perfectly true, I think a key part of the picture is missing: design…

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…

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…

Application localisation:

Hello! I’m Alexey Timin, a Senior Software Engineer at Bumble, in charge of localisation system development. Let me tell you more about our localisation system. We work on two products: Badoo and Bumble and operate more than 150,000 phrases and texts, translated into more than 50 languages. Each project has…

From zero to Cosmos — Part #3

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 finally became a complex unification project — a design system called Cosmos. From zero to Cosmos — Part #1 From zero to Cosmos —…

Delhi to London : What it’s like to be relocated for a new job!

Since I am from India, I always think in terms of Bollywood movies, where everything is possible. Yes, that’s right…everything. Maybe that is why when I started off with Badoo, I always believed that this was within my reach. If I were to make a Bollywood movie of my journey…

Top 5 Bumble Android AMA

A few weeks ago, our Bumble — the parent company operating Badoo and Bumble apps — Android team hosted their first Ask Me Anything (AMA) session on Reddit. It was great! Our Android apps are huge: they have over 1.3 million lines of code, over 210 million downloads on the…