All Engineering

Keeping Public API in Check With the Kotlin Binary Validator Plugin

Within the Stream Chat Android SDK project, we use the Kotlin binary compatibility validator plugin to keep track of all the changes we make to our public API. This is a first-party plugin by JetBrains, though it’s still experimental (it’s an incubator project by JetBrains on Git…

Clean Chat Example App with Jetpack Compose

Stream now provides a Jetpack Compose Chat SDK. Check out the Compose Chat Messaging Tutorial and give it a try today! We’ve recently published a Jetpack Compose design sample on Twitter, recreating the Contacts & Messages design by Mickael Guillaume on Dribbble. The source code …

Activity Feed Personalization 101: Top Feed Features to Improve User Engagement

Personalization comes in many flavors, and the data science team at Stream can help you build your own feeds personalization engine based on your specific needs. In conjunction with our analytics client we recommend tracking every event for every user, such as clicking on a link)…

Jetpack Compose: First Impressions and Learning Resources

As you most certainly already know, Jetpack Compose is the hot new thing for Android UI development. Its promise is to save us by making all the pain points of the old View system and XML layouts go away. Stream now provides a Jetpack Compose Chat SDK. Check out the Compose Chat …

React Native: How To Build Bidirectional Infinite Scroll

Introduction There have been many discussions on Stack Overflow and GitHub around implementing infinite scroll using React Native, on top of FlatList or SectionList. I’ve found that there aren’t any easy solution out there for bidirectional infinite scroll for React Native. Recen…

Swift WebSockets: Starscream or URLSession in 2021?

Building applications such as online games and real-time chat has never been more straightforward since the standardization of the WebSocket protocol in 2011. Before that, most app experiences were plagued with manual refreshes to access the latest data available. Remember F5? Si…

Singleton vs Dependency Injection in Swift

When coding iOS apps, we often create classes that manage a particular aspect of the application. For example, it’s common to develop "manager" classes that encapsulate methods for interacting with a specific application aspect. These aspects commonly include the REST API, WebSoc…

Publishing Android libraries to MavenCentral in 2021

Introduction This is an updated version of an article published two years ago on blog.autsoft.hu. This new version supports non-Android libraries, uses command line GPG handling instead of a specific Windows GUI app, includes new best practices, and uses GitHub Actions for its CI…

Tutorial: How to Build a Slack Clone with React Native – Part 3

In Part 2 of this tutorial, we covered how to build Slack-like navigation, channel list screen, channel screen, reaction picker, and action sheet. In this tutorial, Part 3, we will build various search screens and thread screen. Resources 👇 Below are a few helpful links if you g…

Tutorial: How to Build a Slack Clone with React Native – Part 2

React Native has come a long way since its first release in 2015. In fact, it has enough components, APIs, and supporting libraries in its present state that you can re-create every app that’s out there on the Google Play Store or Apple App Store in no time! In this series, we wi…

Announcing Experimental Multi-Platform Support for the Stream Flutter SDK

Stream is always looking out for the next big thing in developer tools to build new applications. React Native was one of the first mobile development framework supported by our SDKs and is still going strong. We announced support for Dart/Flutter in February of 2020. Flutter has…

Choose Your iOS Dependencies Wisely

Dependencies are vital for most iOS projects. They allow us to speed up development and not reinvent the wheel every time we need components such as networking, rendering, chat, calendar, and many others which can be common to different types of projects. It’s also an efficient w…

How to use GitHub with Android Studio

Android Studio makes it easy to push changes to your favorite Open Source, professional, or personal projects on GitHub. In this tutorial, we’ll learn how to use GitHub with Android Studio. We’ll use an Open Source contribution for context. Android developers use Open Source proj…

Tutorial: How to Build a Slack Clone with React Native – Part 1

React Native has a significant footprint in the mobile development world. And with every new release, it gets better and better in terms of development speed and performance. Building a chat application used to be a massive chunk of work, but with the power of react-native and St…

Styled Components vs. CSS Stylesheets

Over the last few years, CSS-in-JS solutions have become prevalent across the front-end landscape with many offerings such as styled-components, and emotion that provides a way to colocate your components and style definitions. The power of these libraries lies in the ability to …

Stream Is Deprecating Virtual Go – It’s Time to Move to Go Modules

TL;DR Stream released vg almost three years ago, and since its inception, Go has improved quite a bit in regards to its dependency management. Since Go has come so far, we’re now advocating that the community use native Go modules rather than vg. The Gist Stream provides an API a…

Rolling a Custom Docs CMS with Slate and Django REST Framework

The Rundown In 2019 we realized we had a big problem here at Stream. Our documentation for Feeds and Chat was outdated, hard to navigate, and difficult to update due to legacy systems that were in place. We made it a goal to set out and build the best documentation site available…

Prevent Native Race Conditions with React’s Context API

Here on the Stream Services team, we have the pleasure of working with a variety of clients and get to solve exciting challenges daily. This blog post provides a peek into one such occasion by highlighting the intricacies of building a native app in Javascript, and the creative s…

Create a GraphQL API with Node, Mongoose, and Express

GraphQL is a technology that helps developers across the board to build more robust software more quickly. The ability to request all of the information you need in a single request is a game-changer. It has simplified my backend development of APIs for consumption by mobile and …

MongoDB vs. DocumentDB: Which Is Right for You?

Are you trying to decide if you should use MongoDB or DocumentDB? With the recent controversy surrounding licensing with MongoDB, it can be confusing to decide which option is right for your company or project. Amazon decided the core MongoDB code is challenging to scale while re…

Crafting a Command Line Experience that Developers Love

If you’re setting out to build a highly usable developer tool, it goes without saying that a proper CLI to interface with your API is paramount. As Zeit and Heroku have been setting the tone for these types of developer tools by doing extensive research into best practices when i…

How a Go Program Compiles down to Machine Code

Here at Stream, we use Go extensively, and it has drastically improved our productivity. We have also found that by using Go, the speed is outstanding and since we started using it, we have implemented mission-critical portions of our stack, such as our in-house storage engine po…

Go 1.11 Rocket Tutorial

This tutorial combines two of my favorite things, the Go programming language and images of SpaceX rocket launches. With Go rapidly picking up adoption in the developer community, its becoming one of the leading languages for building backend systems. Go’s performance is similar …

Google Feed Personalization and Recommender Systems

Lately, I’ve been using Google’s feed on Android and it contains several interesting best practices for content discovery. Google’s feed strikes an effective balance between machine learning and follow relationships. With the recent advancements in AI, it can be hard to know when…

JavaScript: Promises and Why Async/Await Wins the Battle

Asynchronous functions are a good and bad thing in JavaScript. The good side is that asynchronous functions are non-blocking and, therefore, are fast – especially in a Node.js context. The downside is that dealing with asynchronous functions can be cumbersome, as you sometimes ha…

Simple Steps to Optimize Your App Performance with MongoDB, Redis, and Node.js

First Things First Here at Stream, we power activity feeds for 300+ million end users and love playing around with ways to utilize our product in all sorts of use cases. Most recently, we built Winds, an open-source RSS and Podcast application with a strong focus on UI and UX. Sh…

Building an End-to-End Deep Learning GitHub Discovery Feed

There’s hardly a developer who doesn’t use GitHub. With all those stars, pulls, pushes and merges, GitHub has a plethora of data available describing the developer universe. As a Data Scientist at Stream, my job is to develop recommender systems for our clients so that they can p…

Testing Node.js in 2018

Stream powers feeds for over 300+ million end users. With all of those users relying on our infrastructure, we’re very good about testing everything that gets pushed into production. Our primary codebase is written in Go, with some remaining bits of Python. Our recent showcase ap…

React Fragments – The End of the Wrapper Div

Hi there! I’m Ken. I’m a Developer Advocate over at GetStream.io, where we build personalized and scalable activity feeds. For the last several months, I’ve been working on Winds 2.0, an open-source RSS reader and podcast listening app. It’s built in Node.js, Electron, Redux and …

Fixing the billion dollar mistake in Go by borrowing from Rust

panic: runtime error: invalid memory address or nil pointer dereference If you ever used Go, you probably saw this error at least once. Somewhere a nil pointer or nil interface was passed to a function that doesn’t handle nil. In all cases this is a programming error, either the …

Go Client Now Available

Go is one of the fastest growing languages around. We ourselves use it extensively inside the Stream API service. Support for Go was added almost two years ago by MrHenry and HyperWorks, which open-sourced a Go client. We are proud to announce that starting today, we are releasin…

Building a Node.js Powered API with Express, Mongoose & MongoDB

One of my favorite parts of my job as a Developer Evangelist at Stream is building sample applications. It is an enthralling way to engage and interact with potential and existing customers, as well as show off the fun technology we use and build with every single day. The applic…

Moving Beyond EdgeRank for Personalized Newsfeeds

This blog post is broken into two parts and harkens back to learnings from a prior post. The sum of all these parts is altogether my best effort to provide you with a framework of how to take the creation of personalized news feeds to the next level. Part 1: Theory behind a very …

Personalized Job Feeds and Machine Learning

Product managers for job sites face two fundamental problems. First, the top candidates are not actively looking for a job, making them difficult to seek out and find. Second, the top jobs are quickly filled and typically attract in-network candidates. So, while you have top cand…

Using .IO Domain Names for Production Traffic

We’re currently updating this article. Please check back soon. In the meantime, check out these helpful resources: APIs: Feeds, Messaging UI Kits: Feeds, Messaging Tutorials: Feeds, Messaging

Building Your Own Instagram Discovery Engine: A Step-By-Step Tutorial

Isn’t it great how Instagram’s “Explore” section displays content that matches your interests? When you open the application, the content and recommendations shown are almost always relevant to your specific likes, interests, connections, etc. While it may be fun to think we’re t…

Why we switched from Python to Go

Updated May 14th 2019 to better reflect improvements to Go in the last 2 years (package management, better performance, faster compile times and a more mature ecosystem) Switching to a new language is always a big step, especially when only one of your team members has prior expe…

JavaScript Frontend Framework CLI Showdown

Many modern JavaScript frontend frameworks are complemented by a standalone Command Line Interface (CLI) program that assists with setting up a suitable development environment. Since many developers who work with Stream also use one or more of these frameworks, we like to stay u…

Testing Go at Stream

Stream’s API is used in production by more than 500 companies and 200 million end users. While we like to move fast, we definitely don’t like to break things. An extensive test infrastructure enables us to move quickly and deploy code with confidence. A solid testing workflow is …

Follow Recommendations in Social Networks

Social media is a series of networks connecting individuals, companies, organizations, and groups to one another. These networks can transcend local, national, and international borders connecting people to networks far and wide. With all those connections, how can a user find th…

Adding TypeScript Type Definitions to the Stream JavaScript API Client Library

TypeScript is a language that Stream has been interested in for quite some time. Over the past year, we’ve had an increasing number conversations with TypeScript and Angular developers. So naturally, it’s been our ambition to eventually distribute Type Definitions for our JavaScr…

Examining Decentralized Social Networks

Most companies who create a social media network do so with the end goal of collecting information, interests and habits of their users in order to monetize that data (usually through advertising). They guard this data heavily and many of the largest social networks are trusted e…

Best Practices for Recommendation Engines

In this blogpost I will describe how to implement a feature-rich activity feed that will make relevant and accurate personalization algorithms easier to implement. As we have already explored in previous blog posts, app personalization is linking activity feeds and user engagemen…

Building a Performant API using Go and Cassandra

Introduction Software performance is critical to a SaaS company like Stream and while the majority of our infrastructure is written in Python, we are actively porting portions of our code base to Go. Stream is an API for building scalable feeds and now handles over 20 billion fee…

Factorization Machines for Recommendation Systems

As a Data Scientist that works on Feed Personalization, I find it it important to stay up to date with the current state of Machine Learning and its applications. Most of the time, using some of the better-known recommendation algorithms yields good initial results; however, some…

Example Ranking Methods for Your Feeds

In this short tutorial we will show you how to use Custom Ranking for your activity streams and news feeds. By default all feeds on Stream are ranked chronologically. Custom ranking allows you to take full control over how your feeds are sorted. Some common use cases include: Sho…

In Depth Guide on Building a REST API with Node.js, Restify & MongoDB

Update for August 2017: This guide has been updated for Restify 5 and Mongo 3.4 with modern Javascript practices. Clone the Github repo to get the full working project. Choosing the Technology With the multitude of JavaScript frameworks and databases available nowadays, there are…

Personalization & Machine Learning for News Feeds and Social Networks

Winds is an open source RSS reader is powered by React, Redux, Sails and Stream. This tutorial explains how we’ve built personalization for Winds, as an example of how using Stream makes it easy to build personalized feeds. About Personalization Personalization is a very broad co…

An Introduction to Contextual Bandits

In this post I discuss the Multi Armed Bandit problem and its applications to feed personalization. First, I will use a simple synthetic example to visualize arm selection in with bandit algorithms, I also evaluate the performance of some of the best known algorithms on a dataset…

How to Setup a Highly Available Multi-AZ Cassandra Cluster on AWS EC2

Originally built by Facebook in 2009, Apache Cassandra is a free and open-source distributed database designed to handle large amounts of data across a large number of servers. Cassandra at Stream At Stream, we use Cassandra as the primary data store for our feeds. Cassandra stan…