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…

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…

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…

#1 — Swift and iOS Ninjas Meetup: videos, slides and questions!

London isn’t just the capital of England — it’s also the capital of many other things. Including avoiding eye contact with people on the tube or trying to give you a free magazine. And it’s the capital of paying £12 for a cocktail because the barman has a beard. But…

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…

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…

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…

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…

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…

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…

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…

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 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…

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…

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…

Overview of KotlinConf 2019

I’ve been developing with Kotlin for the past two years, and when I was asked if I’d like to attend KotlinConf 2019 with some of my colleagues, my answer was a great, big Y-E-S! Having the chance to attend what is one of the best conferences for mobile devs, I…

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…

WebRTC on Android: how to enable hardware encoding on multiple devices

For video calls on Badoo and Bumble apps, we use WebRTC with H.264 codec. Relying on relevant documentation, you would think that this codec should work seamlessly on any Android device, starting with Android 5.0. However, in practice, it didn’t go exactly this way. This article covers implementation features of…

Bitmap indexes in Go: unbelievable search speed

Foreword My name is Marko and I gave a talk at Gophercon Russia this year about a very interesting kind of indexes called “bitmap indexes”. I wanted to share it with the community, not only in video format, but as an article too. Please enjoy! Additional materials, slides and all…

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…

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…

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…

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. —…

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…

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…