At our July meetup, there was a surprise blockchain seminar. It was an enlightening session where we delved into the current blockchain trends and learned about Sam Altman's ambitious project, Worldcoin. Many were taken aback when an announcement of listing was made just 5 days later on the 24th 😅.

A special thanks to those who participated in the mission to review the announcement on the dooboo app. It made the event even more memorable.

Check out the photos from the event on Instagram.

Hermes is an open-source JavaScript engine developed by Facebook, specifically designed to improve the startup time of React Native apps. It was first introduced in React Native 0.60.4 in 2019.

React Native apps are typically written in JavaScript, and this code is interpreted by a JavaScript engine before being executed on a device. Previously, most React Native apps used JSC (JavaScriptCore) for code interpretation. However, with an aim to enhance performance, especially for mobile apps, Facebook introduced Hermes.

The key features and advantages of Hermes are:

1. Fast Startup Time: As Hermes directly executes JavaScript compiled into bytecode, it enhances the app's startup time.
2. Low Memory Footprint: Hermes is designed to minimize memory usage, thereby reducing the overall memory consumption of the app.
3. Optimized for React Native: Hermes is optimized for use with React Native, offering potential performance improvements for typical React Native operations.

For more information, check out the blog What is Hermes Engine?.

React Native Architecture refers to the internal structure and operating principles of a React Native application. The initial architecture of React Native consisted of several main components, and over time, enhancements and updates were made to improve the performance and stability of the application. This explanation is based on information up to 2021.

1. Bridge: This was a core component of React Native's initial architecture. The Bridge facilitated communication between the JavaScript thread and the Native thread. It was responsible for sending UI updates, events, etc., generated in JavaScript, to the Native code.

2. JavaScript Core (JSC): This is the JavaScript engine used in iOS. In Android, the JSC is bundled for distribution.

3. Native Modules: These are modules in React Native applications that provide access to the native features of a device. For instance, they allow access to the camera, GPS, and file system.

However, Facebook is continuously working to improve the performance and flexibility of React Native's architecture. New architectural updates, like "Fabric" and "TurboModules," have been introduced.

• Fabric: This is a project to rewrite the UI layer of React Native. It aims to achieve faster UI updates and smoother animations. Fabric minimizes the communication between JavaScript and Native, thereby enhancing performance.

• TurboModules: These are a rewritten version of Native Modules, aiming to improve the communication performance between the JavaScript thread and the Native thread.

The introduction of this new architecture aims to boost the performance of React Native applications and streamline their integration with Native components.

For a more detailed understanding, check out The New Architecture of React Native.

At our June meetup, we continued our discussion from May about UI components, this time with a live coding session. We tackled the Accordion component, which is a bit more challenging and offers more points of consideration than a simple button.

We've brought back live coding to our meetups after a long hiatus. If you're interested in participating, we offer a presentation fee worth 150,000 KRW. As you'll see in our videos, our goal is not to intimidate, but rather to learn and help each other. We encourage you to apply in a relaxed manner.

Presentation application form

Thank you.

On-site photo​

Part of Presentation Video​

• Live Coding UI Components - Part 1 (Feat. Accordion)
• Live Coding UI Components - Part 2 (Feat. Accordion)

In the May meetup, the author presented a thoughtful discourse on UI components and design systems for about an hour. The talk broadly covered crucial aspects we often overlook when developing numerous UI components and examined how to define functional sets and write props according to UI component design principles (user-centric, consistency, simplicity, feedback). Lastly, the importance of reducing all possible props or steps to maintain simplicity was underscored once again.

Finally, we shared a short clip on how to prevent re-rendering caused by inline styles in React. If you found this useful, please don't forget to subscribe, like, and turn notifications on.

"The state of perfection is not when there is nothing more to add, but when there is nothing left to take away," is a widely known quote from "The Little Prince" written by the French author Antoine de Saint-Exupéry. It emphasizes the importance of balance and simplicity in various aspects of functionality, design, and life.

We offer a presentation fee of $150 to our presenters, and the presentation contents can be casually delivered at your discretion for 20 to 50 minutes. If you're interested, please proceed through our presentation application form. Thank you 🙇🏻‍♂️

Part of Presentation Video​

https://www.youtube.com/watch?v=Zbph_vQwGc0

In the April meetup, we continued with content related to Microsoft's MAUI following the February Flutter meetup. First, Park Tae-sung from Idea Sam shared his thoughts on MAUI as a React Native developer.

Secondly, Kim Sang-Hyun from Some Other Place gave a presentation. The title of the presentation was MAUI, a Native-friendly Cross-platform, This is It, and you can check the content through the link. The presentation mainly focuses on how MAUI is different from React Native and Flutter.

We provide a presentation fee of $150 to the speakers, and the presentation can be casually given for 15 to 50 minutes at your discretion. If you are interested, please proceed through the presentation application form. Thank you 🙇🏻‍♂️

Florian Ludot, the CTO of Avanssion Inc., gave a presentation introducing Storybook, a tool that helps developers build scalable and effective services. During the presentation, he guided the audience through the Storybook workflow, from the initial design phase to implementation, deployment, publishing and integration of component libraries, and shared tips and best practices for iterating products at lightning speed. He also emphasized the importance of innovating the UI development process and taking projects to the next level.

Florian Ludot was born and raised in France, spent four years in Japan, and recently moved to Seoul as a developer. He expressed his delight in having had fantastic opportunities to work closely with development and design teams, and to share his knowledge with anyone interested in learning more about the field. He also announced that he is preparing the Seoul iOS Meetup, where everyone is welcome to gather and share knowledge.

For those who missed the meetup, the video is available on https://www.youtube.com/watch?v=ICpn4JrnIHY.

At this meetup, there was a small presentation on the Flutter GetX pattern. Then, we shared the toy Flutter project which was developed to manage meetup donations. The project name is WeCount and sourcecode is on Github.

In addition, some apps made with Cross-Platforms are listed in crossplatform/koreanapps.md. If there's an app you'd like to add, please push a PR.

The first Cross-Platform Korea meetup was held. In 2023, there should be more beneficial knowledge sharing time. First of all, since it was the first day, I, the organizer, continued my presentation while looking back at the React Native Seoul meetup last year.

There was a retrospective of last year's meetup and a return for the informative presentations made at the end of the year..

Since there was no winner by voting, it was determined by the number of likes and views on YouTube, and a prize of 500,000 won was given to the team that announced the FlatLane automated distribution.

Youngji Noh, the leader, was unable to attend, so the agent awarded the prize money.

Next, I shared my experience on How to handle Navigation in Flutter. It deals with the experience of built-in navigation and Go Router, and contains knowledge that is good to know in advance when choosing navigation in Flutter.

Then, we shared How to handle navigation in React Native and looked into what React Native is trying to do.

At this meetup, presentations were made in groups determined at the previous meetup. We would like to thank the presenters again for their hard work.

The first announcement was made by Hyungu Kang, a developer at Sandbird. We learned in detail about FlatList, which is often used in React Native, and how to optimize it. The presentation video is attached at the link below.

The second presentation was made by Noh Young-ji, who works at Connect Dream. You shared how to automate app builds and deployments with Fastlane. Please check the presentation video at the link below.

Unfortunately, I couldn't share the rest of the presentation because the video was cut off, but I would also like to thank Lee Tae-heon for sharing how to use Naver Map.

As promised, a prize of 500,000 won will be given to the team that proceeded with the presentation. Prizes will be awarded at the next meetup on January 25th :)