Chapter 1

Skywatching

IN THIS CHAPTER

Learning the history of Bluesky

Understanding what makes up Bluesky

Seeing how Bluesky compares to other microblogging platforms

Welcome to the kaleidoscope of butterflies called Bluesky. (Did you know a group of butterflies was called a kaleidoscope? Neither did we.) Originally a project within Twitter, Bluesky is a new microblogging platform that's taking on Twitter (now called X) as well as other competing platforms, including Mastodon and Meta's Threads.

Microblogging describes the sharing of short posts with a character limit, and these posts can include links to other websites as well as images, videos, and other media formats such as animated GIFs. Microblogging social networks also allow you to like other posts, send short replies to posts, and share posts with others.

In this chapter, you get the TL;DR (that's 21st-century slang for too long; didn't read) version of the history of Bluesky and why its popularity spiked near the end of 2024. Next, you learn what makes up Bluesky. Finally, you see how Bluesky compares to other microblogging social media platforms, including X, which has been a driver of Bluesky growth. Let's fly.

A Brief History of Bluesky

Since Bluesky's logo is a butterfly, you could think of Twitter as creating the cocoon from which Bluesky emerged. Bluesky has come a long way since its inception in 2019 (hey, that was way before the COVID-19 pandemic) and its teenage growing pains. This section takes you on a quick tour, and then describes the features added to Bluesky since its public launch in early 2024.

Step into the Wayback Machine

Just like the production of this book, the development of Bluesky has been on a fast track. Follow along the timeline with us:

• December 2019: Twitter CEO Jack Dorsey announces the plan to create Bluesky as an open and decentralized standard for social media, including Twitter.
• August 2021: Software engineer Lantian Jay Graber becomes the leader of the Bluesky project. Twitter provides $13 million in seed funding. (Fun fact: The name Lantian means blue sky in Mandarin Chinese, but her becoming Bluesky's leader is only a spooky coincidence.)
• October 2021: Graber incorporates the Bluesky project as an independent public benefit corporation called Bluesky Social and becomes its first CEO. Jack Dorsey sits on the board.
• March 2022: Bluesky hires its first three employees.
• October 2022: Elon Musk buys Twitter and immediately severs all legal and financial ties with Bluesky Social. Bluesky has no problem with this.
• February 2023: Bluesky starts construction as an invite-only iOS beta app. In April, the beta app is released for Android. By July 2023, Bluesky has about 200,000 users.
• February 2024: Bluesky launches its social media app and opens registration to the general public.
• May 2024: Jack Dorsey leaves the Bluesky board. In an interview with Pirate Wires online magazine, Dorsey said Bluesky was "literally repeating all the mistakes [Twitter] made as a company." (www.piratewires.com/p/interview-with-jack-dorsey-mike-solana).
• August 2024: Brazil's supreme court blocks Twitter, now called X, in its country. As a result, Bluesky gains over four million users in under two weeks.
• October 2024: X makes changes to its block feature and its terms of service to analyze users' content for AI training purposes by default. Four days after that announcement, over 1.2 million users join Bluesky. On October 24, Bluesky announces its user base is now 13 million.
• November 2024: Following the U.S. presidential election results, millions of users join Bluesky as an X alternative. On November 19, Bluesky's user base is 20 million, which is a tripling of its user base in just three months.

As of February 2025, Bluesky surpassed 30 million users - and is dealing with the problems that come with more users. With every growth wave comes a predictable increase in bad actors and moderation reports, so Bluesky has hired more human moderators, improved automated tooling for spam and scam detection, and more.

Features added along the way

Bluesky's rapid growth makes us wonder if new developers get mandatory bee costumes on their first day. The development team would probably agree that they're the dictionary definition of the idiom "busy as a bee." Here are the features these bees have added in under two years:

• Report and review functions: Users can report posts and accounts that violate Bluesky's community guidelines. Bluesky uses a combination of automated tooling to flag potentially harmful content and a human moderation team.
• Starter packs: These curated collections of accounts help you quickly find users with shared interests. Most competitors are thinking of replicating this Bluesky feature.
• Moderation lists: Users can create lists to block or mute specific contents as well as other accounts.
• Labels: You can label your posts in different categories, which is helpful if you have sensitive information that's for only specific users, such as those 18 and older.
• Reply controls: This feature lets you control who can reply to your posts - everyone, followers, or no one.
• Sorting preferences: You can sort your Bluesky home page feed and message threads using settings such as most recent or most popular.
• Hidden posts: If you never want to see a post again, click or tap it and select Hide Post to remove it from your feed.
• Likes tab: You can like posts and access them anytime by selecting the Likes tab.
• Suggested tags: This feature suggests users to tag in your posts. Type @ in the post, and a list of suggested users appears so you can choose the Bluesky user you want to tag.
• Notifications: You can enable notifications to receive alerts on your phone for different events, such as someone liking your latest post.
• Emojis: When you compose a post in the Bluesky website, click or tap the emoji icon to select an emoji to add.
• Chats: You can have one-on-one text conversations with another Bluesky user. You can also report inappropriate chats you receive to Bluesky moderators.
• Video and audio player: You can place a video link or an audio link in your post. You can also play video and audio in another user's post.
• Custom domains: You can personalize your Bluesky handle (for example, @name.bsky.social) with your own domain name.

Understanding How Bluesky Works

Bluesky has been developed from the ground up as an open source framework for building social media apps. As part of this framework, you have your choice of algorithm so you can best curate the content you see. Let's bring out our magnifying glass to look more closely at the AT Protocol, the system that powers the Bluesky butterfly.

Open source versus a closed ecosystem

Bluesky developed the Authenticated Transfer Protocol, also called AT Protocol or ATProto. (We use the latter because we're efficient.) Indeed, Bluesky was created as a proof of concept for ATProto.

ATProto is both a protocol and an open standard for building social network apps, and it comes with a standard format for user identity, follows, and data on social apps. As you may have guessed, when different social networking apps use the same standard protocol such as ATProto, they can interoperate and users can move among them.

ATProto focuses on six key areas:

• User experience
• Platform interoperability
• Discoverability
• Network scalability
• User data portability
• Social graphs

In sum, ATProto is an open standard for social media that many apps and networks can adopt. So, just as Bluesky is built upon ATProto, so too can other social networks. In fact, many already have! New apps are popping up for longform blogging, a web forum, an audio space app, and more built on ATProto.

Bluesky has pledged to transfer ATProto's development to an independent standards body so that ATProto isn't controlled by any one company. As of this writing, Bluesky hasn't released details about what body will be chosen and when the transfer will take place.

Eager to learn more about ATProto from a technical perspective? Visit the ATProto website at https://atproto.com/guides/faq to read answers to their frequently asked questions.

Your choice of algorithm

When Bluesky launched its invite-only iOS app, CEO Jay Graber talked about algorithmic choice. You can find the article at https://bsky.social/about/blog/3-30-2023-algorithmic-choice, but we summarize it for you here because we like you and because of that whole TL;DR thing we promised at the top of the chapter.

Graber noted that there's usually little transparency about the content shown to you on other social networks, which has led to user backlash about the perceived manipulation of feed timelines by the algorithm. (Oh, my, do we empathize.) You may be able to filter out some features, such...