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 #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 —…

A Custom LayoutManager Case: Bumble Beeline

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Burnt-out workers: is there a way out?

You work at a good company. You are surrounded by great professionals, you earn a decent salary and every day you carry out important and needful tasks. Elon Musk is launching satellites, Boston Dynamics’ robots are getting better and better. The weather is great, the sun is shining, nature is…

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…

Badoo Android Architectural Journey

A talk presented at the Londroid meetup about the architectural journey of Android development at Badoo. The abstract: At Badoo, we have a long history when it comes to Android development. Since the beginning, the product has experienced huge growth, and our codebase and our team have grown with…

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…

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…

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…

Run, config, run: How we speed up config deploy

Configuration files (configs) are an integral part of most applications, but practice shows that they are far from being the most popular topic of discussion. Conversations about configs are mostly limited to discussing working with them directly in the code: how to structure them, whether or not using environmental variables…

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…

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 #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…

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…

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…

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…

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…

Informal relationships

Many years ago I joined a company as a developer and soon witnessed something odd. Another department’s teamlead called up one of his subordinates in the middle of the day and told him: ‘Here, come and get this money and go to a store and grab me some drinks and…

Achieving State Of The Art Results In Natural Language Processing

Part 2: ELMo, BERT and MT-DNN In my previous article I covered some of the fundamental concepts in NLP. This time, I will introduce ELMo, BERT and MT-DNN, architectures which leverage these concepts and have recently achieved some State Of The Art (SOTA) results on NLP tasks. Embeddings from Language Models (ELMo) An introduction to ELMo can be found in this…

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…

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…

Rolling out automation within a couple of hours: PHPUnit, Selenium and Composer

Hello Medium readers! My name is Vitaliy Kotov and I work at Badoo in the QA department, where I spend a lot of my time on test automation. I was recently faced with the task of rolling out Selenium tests as fast as possible for one of our projects. 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…

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…

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…