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…

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…

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…

How we achieved a 6x reduction of ANRs. Part 2: Fixing ANRs

In the first part, we discussed what ANR is and what are the ways of tracking it. In this article, you will find information on what problems we found in our application, how we fixed them, and the results we achieved. Application Startup The first thing to do if you want to…

Translating Dust templates to JSX

It appeared in the middle of the decade (plagued by the endless JavaScript framework wars), embraced the DOM, shocked everyone by mixing HTML with JavaScript and transformed the web development landscape beyond recognition. All those accomplishments, without even being a framework. Love it or hate it, React…

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…

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…

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…

Data classes in Kotlin: how do they impact an application size

Kotlin has numerous excellent features: null safety, smart casts, string interpolation and more. However, one of its features developers love the most, I have observed, are data classes. They are so well-loved that they are often used where no data class functionality is required. In this article, with the help…

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…

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: Deep Learning for Engineers

Introduction to Transfer Learning In this article, we use the concepts we saw in part 1 article to unleash the power of neural networks and the reason for their current popularity, namely their reusability. We learn how we can (partially) automate the feature engineering part and how this opens a new world of possibilities…

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…

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…

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…

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…

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…

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…

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…

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…

Guide to mobile app autotesting tools

… for though it has many omissions and contains much that is apocryphal, or at least wildly inaccurate, it scores over the older, more pedestrian work in two important respects. First, it’s slightly cheaper; and secondly it has the words DON’T PANIC printed in large friendly letters on its cover. —…

What Google I/O 2019 addressed: Android 10, AR-applications and much more

In this article I’ll share my thoughts on Google I/O 2019 that my colleagues and I attended recently (and Badoo were even mentioned in one of the talks). During the three days, there were more than 150 talks, lots of choice as you can see, but I really wanted to…

Crowdtesting

source: pinterest.co.uk It’s been a while since I first heard about crowdsourced testing platforms. It was a time when I had just started to be interested in QA, and when I was browsing Google one day, I found a forum, where a link to the site uTest.com was posted. After a brief…

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…

PHP code static analysis based on the example of PHPStan, Phan and Psalm

As a company Badoo has been around for over 12 years now. We have a lot of PHP code (millions of lines of code) and there are probably still strings of code that we use which were written all 12 years ago. Some of them were written back in the…