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Thoughts about Hack Day from Tech Week 2024!

Hello. This is Ujin Jeong, an Android engineer developing LINE Album and sharing services, and Seunghee Chung, a designer responsible for common UX in the Product UX organization.

We participated in the Tech Week 2024 event held internally from September 2 to 6. Tech Week 2024, themed "Global all-engineer collaboration forum", took place at the LY Corporation office in Kioicho, Tokyo. The event featured three programs: "Tech All-Hands Meeting", "Tech Conference", and "Hack Day". Seunghee and I participated in the internal hackathon, Hack Day. For more details on each program, please refer to the article My experience at Tech Week 2024 in Tokyo. In this article, we want to share the dynamic atmosphere of our first global internal event and the process of creating a product during the internal hackathon.

Hack Day

The most memorable part of Tech Week 2024 was Hack Day, a traditional hackathon event that started at Yahoo! JAPAN Corporation before the merger and continues at LY Corporation. Hack Day is an internal hackathon where you can develop anything you want, and anyone with a creative idea can participate. I always hoped to join a hackathon while working at an IT company, and experiencing it firsthand provided insights beyond my imagination.

There were two ways to participate in Hack Day: the "General" category, where participants are selected from each global branch, and the "Global Mixed" category, where teams are formed with members from at least two different countries or regions. The General category had preliminary rounds at each branch, while the Global Mixed category involved an online exchange meeting to form teams, with final participants selected by lottery. Woojin and Seunghee participated in the General and Global Mixed categories, respectively.

The development took place over two days, from 9 AM to 9 PM, totaling 24 hours. Let me introduce what product we developed at Hack Day and how we did it.

Painter Sally (tentative name) development story - Ujin Jeong

I participated in the General category with four fellow developers from LINE Plus. Our team's theme was to combine a game with an AI bot that draws LINE FRIENDS. Recently, Stability AI's Stable Diffusion, which generates images or characters, has been a hot topic. We couldn't find an AI model that accurately drew LINE FRIENDS characters, so we wanted to create a Sally bot that could draw cute LINE FRIENDS through AI training. We thought it would be an interesting app if we could use these drawings in a game.

In this project, LINE FRIENDS characters were used experimentally and are not official character modifications.

Pre-meeting and design

Before starting development, we held pre-meetings and designed the app. We planned the overall app's features and design and set the rules for the game using AI-generated drawings. Since all four of us were client developers, using AI technology was a bit challenging. However, by studying together and focusing on model development during the design phase, we were able to create a satisfactory model within the time frame.

Development process

During the development process, we faced several challenges and learned a lot from overcoming them.

The first challenge was collecting and refining the training data for the AI model. We needed to gather numerous images to train the AI on various appearances of LINE FRIENDS characters. It was crucial to maintain data quality while including diverse variations.

The second challenge was optimizing the AI model's performance. The initial model often failed to accurately depict character details. We conducted multiple experiments and tuning sessions to improve this. Balancing the model's training speed and accuracy was a significant challenge.

The third challenge was optimizing communication between the client and server. We worked on ensuring that images generated by the AI model were delivered to the client in real-time and used in the game without causing delays.

During development, we saw many global colleagues communicating tirelessly, even late into the night, using translators if needed. Despite the language barrier, the passionate discussions to achieve a common goal highlighted the intense energy of Hack Day.

Introducing the result

Our team completed an AI-based app called Painter Sally (tentative name). This app draws pictures containing LINE FRIENDS characters based on input keywords. Users can then present these drawings to others and enjoy a game of guessing the input keywords.

Sample image

On the last day of Hack Day, there was an exhibition to showcase the results. We presented our project and shared it with other teams. Many people from various branches and countries came to try drawing LINE FRIENDS characters themselves and left positive feedback.

Character images are for sample purposes.

Automatic Love development story - Seunghee Chung

For my first Hack Day, I chose the theme of "love". As technology's influence on life grows and tech-based products become more sophisticated, I believe it's crucial for designers to ensure that UX is meaningfully designed within the product's mechanisms and to understand the value behind the visible screen.

In today's world, filled with transformative energy from replication technologies like deepfake, I thought it would be interesting to connect the value of authenticity we must not lose with the concept of replication in a dual manner.

Meet the truest half

Born from this idea, "Automatic Love" is a social discovery platform centered around a virtual self at the intersection of physical and digital selves. It started with the thought, "What if my virtual self (AI Twin) went on a date with someone else on my behalf?" We developed a bold and new dating experience that addresses the pain points of getting to know someone in the early stages of a relationship and allows users to observe their virtual self dating.

Combining physical and digital selves

The operation of Automatic Love is both idealistic and practical. The user's AI Twin, created based on their data, matches with other AI Twins simultaneously, quickly measuring chemistry and proposing real meetings with the best-matched partner on behalf of the user.

The AI Twin is not just a simple digital copy of the user. It's a digital self that complexly reflects the user's inner self. We created the AI Twin based on chat data to reflect not only the user's appearance and voice but also their identity as a human being, adding realism and reducing the risk of hallucination.

The feature allowing users to observe their AI Twin's conversations with others is a key function of the app and a crucial touchpoint for deciding on real meetings. We created a consistent design language to complete the virtual chat space that users can access anytime. We used the design motif of "folders" to express the digital self, placing the user's profile inside to maximize presence in the virtual space.

We actively applied emotion-based UX. The folder of a frequently viewed partner appears larger, reflecting growing affection, and we used vibrant and warm gradient colors throughout the app to express the user's digital integrity in a realistic format.

Efforts made by a Global Mixed team

Our "Global Mixed" team of Korean and Japanese colleagues, created a work environment where everyone could freely express their opinions. We wore team uniforms with the "Cats" logo, our team name, during Hack Day, showing our strong camaraderie. The sense of unity we felt with our team was a significant driving force in visualizing a project themed around "love".

We stepped beyond our fixed roles as designers and developers, with everyone participating in the entire design process and playing a central role in UX design. We freely discussed the current and future state of dating apps from our cultural perspectives and worked to incorporate universal cultural codes that everyone could relate to when designing conversation topics for AI Twin dates. Considering the hackathon's nature, where we didn't have to worry about future development and commercialization, our common goal was to focus on discovering new values we wanted to propose to the world. As a designer, I distinguished between the core areas of design that must be conveyed and the realistically implementable parts, strategically coordinating between them to complete the work.

Participants were given a surprising amount of autonomy within a limited time, so the development process varied by team. This allowed us to broaden our perspective on collaboration between designers and developers. From branding to UI/UX and advertising videos, I want to thank my team members for trusting and supporting my decisions throughout the design process of "Automatic Love".

Our team was honored to receive the design award for Automatic Love. Building on the valuable achievement of winning the design award, we will continue to create more inspiring LY services in the future.

In conclusion

The theme of Tech Week 2024 was "Global all-engineer collaboration forum", allowing us to meet many colleagues from around the world in one place. During the hackathon, working together in an open space allowed us to experience not only the results but also the entire collaboration process leading to those results. The five-day journey of exchanging feedback with colleagues in a free atmosphere, sharing ideas reflecting our values, and combining these ideas with technology was meaningful in many ways. We gained a lot of insights and rekindled out interest in development by participating day and night.

On the final presentation day, we could walk around the booths and experience the completed results firsthand. The exhibition was filled with the positive energy of creators. From an AR game using Apple's ARKit body tracking technology to avoid obstacles to a wearable device predicting how bad someone needs a toilet, the atmosphere was not one of sharp competition but rather a shared passion and responsibility to solve everyday inconveniences or propose new standards with creativity. We want to continue creating more innovative and creative LY services based on the lessons and inspiration gained from participating in Tech Week. See you next time, hackers!