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LINE has been hosting an annual technology conference, a.k.a. LINE Developer Day, in Tokyo since 2015, and this event has been evolving in size and quality ever since. In November 2018, LINE DEVELOPER DAY 2018 was held at Happoen Garden in Tokyo with the participation of more than 1,000 developers. As I was providing support for this conference from Korea, I attended the event and I’d like to share a few snapshots of LINE DEVELOPER DAY 2018.

A wide range of sessions were offered under the main theme of “Next LINE”. The purpose of the conference was to present LINE’s vision and strategy in pioneering new technologies and showcasing technical knowledge and experiences of the LINE engineers in their endeavor to overcome challenges. LINE DEVELOPER DAY 2018 was organized in four different thematic tracks together with poster sessions and lightning talks, offering a total of 60 sessions for the participants. Topics ranged from LINE’s latest entry into AI and Blockchain arenas, infrastructure, security and data technologies underpinning LINE’s overall services, LINE’s open APIs and experiences from its global service platforms. 

There were interesting demonstrations as well: a face recognition game called Face Play using LINE video calls and a photo booth with Clova voice recognition. Many stayed and enjoyed the after-party at the end of the day, not to miss the “once-in-a-year” networking opportunity.

Opening Session

LINE’s CTO Euivin Park gave a keynote speech on “Next LINE” at the opening session with the two keywords: Connect and Mutually Beneficial Ecosystem. For the first keyword, “Connect”, she emphasized the value that can be delivered to users by connecting online contents with offline devices such as smart speakers and automobiles. Euivin added that LINE was focusing on the development of enabling technologies such as search, recommendation, personalization, speech recognition and OCR. The second keyword was “Mutually Beneficial Ecosystem” in which developers could realize their potential without limitation and users could access services to meet their needs and get rewarded for their contributions back into the ecosystem. To this end, LINE would expand its open APIs and Blockchain service, LINK Chain.



LINE embarked on its business as a messaging app company. However, various topics covered in each session made me realize that LINE was now leading today’s tech scene in many different playing fields. Sessions were presented either in Japanese or English with simultaneous interpretation for those who didn’t speak the respective languages. The four tracks of sessions were held with the following agenda:

Hall AResearch on large-scale development and operations of LINE’s infrastructure and data platforms and progress on building new platforms for Clova/AI and blockchain
Hall BVarious topics including advertisement platform, natural language processing, IoT, front-end development, machine learning and data analysis platform
Hall CPresentations by guest speakers about their experience and know-hows in messaging API (LINE bot) and Clova Extensions Kit development
Hall DVoIP platform for full HD LINE free calls, BITBOX security architecture, iOS emoji development and more

Presentation slides

Most of the slides were presented in English, and you can check them out with the following link. You can also find the Japanese version of the video clip content at logmi. Google Chrome does a relatively good job with translation.

This-and-that of LINE DEVELOPER DAY 2018

The venue is called Happoen Garden (which literally means a garden beautiful from eight angles) with a real historical vibe and view. Happoen Garden is known as a popular spot for traditional wedding ceremonies and conferences. I found it interesting that the address of Happoen Garden was all in ones, “1-1-1”.

Lightning talks

Nowadays technology conferences often offer a lightning talk session, and LINE DEVELOPER DAY 2018 had one, too. Many lightning talks are usually capped at five minutes with speakers taking the stage on a first come, first serve basis. At LINE Developer Day 2018, a slightly different format was applied, allotting 10 minutes for each speaker as most of the speakers were LINERs. There were many high-quality “short” presentations with interesting insights and perspectives.

Poster sessions

Poster sessions are not often seen at technology conferences. It is more common for academic or research competitions where presenters set up their posters and explain their topics when judges approach. I wasn’t sure if this format would work at a technology conference or if it could attract people’s attention. Many participants turned up between sessions and during lunch time. Each poster booth was busy with discussions and questions about different topics presented. I thought this format can be tried out with other events as well.

Networking event

There was a networking event for everyone after all the sessions were finished. As there was a 30-minute break before the after-party, I was a little bit worried people might not stick around. But, we had a good turnout! Everyone seemed to enjoy the party and networking chance. Special thanks to Brown on the golden ale bottles!



All the participants went home with a special souvenir wrapped with the LINE DEVELOPER DAY 2018 edition furoshiki, traditional Japanese wrapping cloth. Inside was a 3-tiered paper jubako box, containing a wireless charger,  a coaster and a delicious Dorayaki. I finished Dorayaki right away and I’m making a very good use of the wireless charger and coaster. It was indeed unique and delightful present especially for developers.

Trailer for the LINE DEVELOPR DAY 2018

Please take a look at this short trailer to get the feel of the day. Even if you don’t speak Japanese, you could still fully enjoy the event because simultaneous translation was provided for many of the sessions. Get your hopes up for ever-evolving, upcoming LINE Developer Day!