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…

Singleton, Service Locator and tests in iOS

In this article, I want to review the usage of Singleton and Service Locator patterns in iOS and the reasons why they are often called anti-patterns. We’ll learn when and how to use them, while keeping our code testable. Singleton Singleton is a class which has only one instance existing at…

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…

Catching bugs on a client

Our team develops several products, Badoo and Bumble, two of the world’s largest dating and connection applications. For both, we have a web version (desktop and mobile) and mobile applications (Android and iOS). With more than millions of users, it’s important for us to gather client-side errors, and for this…

How we achieved a 6x reduction of ANRs. Part 1: Collecting Data

One of the worst things that can happen to your app’s responsiveness is an Application Not Responding (ANR) dialogue. A high ANR rate may affect user experience and, potentially, Google Play search positions and featuring. At the beginning of the year, we had ANR rate above the Google Play threshold…

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…

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…

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…

Scalable Jetpack Compose Navigation

Introduction For one of my recent personal projects, I decided to make Jetpack Compose a first-class citizen. For me, this meant that my app would use a single activity, and all the navigation would be performed using Compose. When I originally started investigating the feasibility of this, Jetpack Compose Navigation did…

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…

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…

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…

Universal links for Android and iOS

Sharing between platforms should always work Mobile apps have given a huge amount of good things to the human race, but at the same time, they have broken the internet. Instead of easy-to-understand links to sites which can be copied and shared, now you have to tell people what app to use to access which content. …

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…

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…

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…

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…

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…

System under control — how to automate integration tests

Nobody wants to discover a production service laying down and not working, or even failing to behave as expected, with errors and incorrect data processing. On one occasion, we — Bumble, the parent company operating Badoo and Bumble apps — decided to greatly reduce such inappropriate behaviour through the use…

Implementing UI in iOS: Better, faster, and it scales!

A few months ago I came across a very interesting documentary series on Netflix called Abstract, they basically explore the output of professional designers from different sectors like architecture, graphic design, fashion, … in their workplaces. It was easy to spot some similarities in the work of designers from…

High-Precision Time: how to use fractional seconds in MySQL and PHP

Once I caught myself thinking about time in databases and realised that I nearly always used time with one-second precision just because it was a common way to it, as well as because that was exactly what was written in manuals in lots of examples. Today, however, this level of…

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…

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…

How we tested iOS 12 Beta

I want to share why it’s important to test betas, how we do it in Badoo and what interesting cases we found during our testing of iOS 12 Beta. Why do we test betas?

PHP Xdebug proxy: when Xdebug’s standard capabilities are insufficient

Xdebug is often used for debugging PHP programs. However, IDE and Xdebug’s standard capabilities are not always sufficient. Some, but not all, problems can be resolved using the Xdebug proxy, pydbgpproxy. This is why I have created a PHP Xdebug proxy based on the asynchronous framework, amphp. In this article…