Overview of KotlinConf 2019

I’ve been developing with Kotlin for the past two years, and when I was asked if I’d like to attend KotlinConf 2019 with some of my colleagues, my answer was a great, big Y-E-S! Having the chance to attend what is one of the best conferences for mobile devs, I…

Client-side neural networks

Historical background The popularity of machine learning and neural networks is growing every day, and faster than we could ever have imagined. Many industry players are contributing, and client-side frameworks are developing rapidly. Many libraries, such as TensorFlow, are constantly releasing new versions. More mobile devices are now receiving hardware support for…

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…

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.

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…

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…

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…

Part 1: Deep Learning for Engineers

Introduction Deep learning has become one of the most discussed topics in the Data Science community. It has long made sense for the Bumble team — the parent company operating Badoo and Bumble apps — to use deep learning on a multitude of tasks. With over millions of users around the…

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…

Part 1: Dynamic Delivery in multi-module projects at Bumble

Dynamic Delivery is a technology which allows you to install and delete parts of an application while the application is working, in order to reduce the space it occupied. If there are functions not being used, what is the point of a user having them on their device? In part…

MVI beyond state reducers

This is the first part in a series of articles on Android architecture in Badoo. You can find the next one here: Part II — Building a system of reactive components with Kotlin Story time: problems of state Your application has a state at any given time that determines its behaviour and what the user…

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…

When pigs fly: optimising bytecode interpreters

“No matter how hard you try, you can’t make a racehorse out of a pig. You can, however, make a faster pig.” — A comment in the Emacs source code. Everyone knows that pigs can’t fly — just like everyone thinks they know that bytecode interpreters, as a technology for…

Routing for iOS: universal navigation without rewriting the app

What’s wrong with navigation anyway? Almost every app has a navigation between different internal components and it seems like it shouldn’t be a problem. UIKit contains more or less convenient containers like UINavigationController, UITabBarController and a flexible way to present screens modally. We, as developers, just need to use the right tools. However, as soon…

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…

Screen navigation in iOS

In this article, we will go through different ways of presenting screens in the iOS app. We will start with most straightforward cases and eventually go through some advanced scenarios. In a nutshell we will be adding more abstraction layers to make our screens decoupled and navigation testable by unit…

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…

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…

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…

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…

Liveprof will show you how and why the performance of your PHP app changes over time

App performance is one of the key criteria for evaluating developers’ work. Profiler is a tool used for optimising the performance of PHP apps in particular. If you’re seeing an increased response time but you’re not sure which parts of the code are causing it, you can use XHProf to…

Using Hopper to investigate an IOS bug

In this article, I share how we investigated a bug in UIKit, which Apple wasn’t able to solve since the introduction of a new major iOS version until the recent release of iOS 13.4.1. The problem was first noticed in August 2019 with the first beta versions of iOS13. In…

Dub-dub 2019: my take on what’s new at WWDC

In this article I share my impressions of the conference: scroll down for, not just read about important updates and an overview of the sessions, but also something on my own personal feelings, having spent time with a happy crowd of people chanting, “Dub-dub! DC!” and dreaming of shaking Tim…

Generating multi-brand multi-platform icons with Sketch and a Node.js script

This is the second part of a post about the creation of a pipeline that can take a Sketch file and export all the icons included in the file, in different formats, for different platforms, with the possibility of AB testing each icon. You can read the first part of…

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…