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…

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…

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…

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…

From zero to Cosmos — Part #1

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 eventually became a complex unification project — a design system called Cosmos. As some of you may know, every good story follows a…

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…

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…

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…

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…

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…

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…

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…

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?

Aspiring team lead?

Six tips on how to meet deadlines and develop your team When I became a team lead for the first time, I started going to lots of conferences and reading deep books on team management. I was reading all about what I should be and how I should develop, but it was still not clear to me what exactly I should…

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…

Server-provided animations in iOS apps

Hi everyone! About six months ago we launched one of Badoo’s most exciting features: Live Streaming. One of its main functionalities is that viewers can send gifts to their favourite streamers to express their appreciation. We wanted to make the gifts as fancy and as engaging as possible, so it…

Modularising an iOS app

At Bumble — the parent company operating Badoo and Bumble apps — the iOS development team have been involved in creating modules for several years now. A large part of the new code is also being developed outside the apps’ code base. As a result of this work, we now…

Swipe right on Motion Layout

How to get into the swiping game with the beta version of Motion Layout Google I/O 2019 finished recently and we got our updates on the latest improvement of our favorite SDK. What particularly piqued my interest was the presentation by Nicolas Roard and John Hoford on upcoming functionalities of Constraint Layout, and more precisely, its offspring, MotionLayout. By announcing the release of the…

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…

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…

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 …

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…

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…

A Custom LayoutManager Case: Bumble Beeline

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