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…

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…

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…

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…

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…

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 —…

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…

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…

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…

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…

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…

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…

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…

Fixing serialization of Kotlin objects once and for all

Some time ago, I read an article describing a problem experienced with Kotlin objects and serialization using built-in Java methods. The author suggests an amazing solution involving adding the readResolve method to each object implementing java.io.Serializable rather than using instance checks. Despite this approach seemingly being the most correct one…

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…

White Box Testing With Appium Espresso Driver

At Badoo, we have techies who strongly believe in contributing to the open source community. This article is about how I contributed a very useful feature called ‘backdoor’ to Appium which solves lots of problems related to Android UI automation. There are a few examples of it in this article…

How 3 Process Patterns will change the way you do Test Automation

A few years ago, here at Bumble — the parent company that operates Badoo and Bumble apps — we started to shift towards using autotests more in our development, testing and release processes. We have, however, encountered a few challenges along the way. Before we start, you might be curious…

Interface localisation: adapting text fields for RTL languages

Adapting applications and sites for right-to-left (RTL) languages is an issue encountered by developers working on many products under development and being introduced onto new markets. There was a point when we at Bumble — the parent company operating Badoo and Bumble apps — also found ourselves in this situation…

Making custom designable UI components

Hi there! I’m Valera, iOS Padawan at Badoo. Here in our company we are crazy about UI and spend plenty of time designing, polishing and improving the user interface to make our users happy, not only about the services we provide, but also about the look and feel of the…

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…

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…

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…

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 …

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…

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…