LINE DEVELOPER DAY 2020 Attracts Biggest International Audience to Date with Nearly 10,000 Viewers

2020.11.27 ALL

■ Two-thirds of the registered viewers tuned in from abroad to the first all online LINE DEV DAY

■ Lineup included 36 outside speakers — including engineers from start-ups and established corporations and leading university researchers

■ LINE CTO Euivin Park put spotlight on technology’s capacity to overcome challenges facing the world today


TOKYO – November 27, 2020 – LINE’s annual technology conference for developers and engineers, LINE DEVELOPER DAY, moved completely online this year for the first time — and in the process enjoyed its best ever international audience, with thousands of people tuning in from around the world. Held Nov. 25-27, LINE DEVELOPER DAY 2020 offered sessions on the latest developments and challenges facing LINE’s key technical fields, including LINE’s future AI products, Fintech and Blockchain technology, cross-platform mobile security, data infrastructure, server-side, and front-end technology.


As COVID-19 continues to impact the world, LINE DEV DAY switched to an all-online format over the course of three-days, with more than 150 sessions presenting LINE’s vision and strategy in pioneering new technologies and showcasing the technical knowledge of LINE engineers. More than 200 speakers participated in the three-day event — including engineers from LINE and its affiliates, as well as 36 people from outside of LINE. Nearly 10,000 viewers registered for this year’s DEV DAY, with two-thirds of them based outside of Japan — a huge jump from last year, when only 10% of online viewers watched from abroad. All sessions were available for viewing on LINE LIVE (either in English or with English subtitles), with video archives on the LINE Developers’ YouTube channel. -

DEV DAY kicked off with a keynote address by CTO Park Euivin, who talked about LINE's recent technical challenges and initiatives, areas of particular focus, and thoughts on the future. Then, Park was joined by Yahoo! JAPAN CTO Fujimon Chiaki to talk about how the two companies are both using technology to overcome social obstacles and other challenges. LINE is in the process of being integrated with Z Holdings, while Yahoo! JAPAN is one of the core subsidiaries of Z Holdings.

“There are still many things that can be done with the power of technology, in Japan and globally,” said Park. “We have various issues facing society, such as COVID-19, and various ways to make life more convenient and enriched. This is an important reason why we want to work together.”

“As our respective CEOs expressed the intent to unite under one team, so shall our engineers,” said Fujimon. “Together, we will tackle social challenges in Japan.”

The keynote also highlighted LINE’s technological achievements in a variety of services. Demand for digital-based communication has increased this year, with LINE’s video call feature receiving several enhancements, and seeing an increase of 235% between February and May. LINE’s data infrastructure, or “Information Universe” (IU), now comprises consolidated data of over 270 PB (petabytes) of storage, and grows at a rate of 700 billion records each day.


“We saw 16 times the usual traffic during peak times,” said Park. “So, we provided load balancing to maximize performance and implemented changes so that data centers in various regions can be dynamically distributed and used according to network conditions.”

A notable achievement outside of Japan included the launch of LINE BK, a banking service fully integrated with LINE. LINE also plans to expand banking services into other countries, including Japan, Taiwan, and Indonesia. See press release:

Another technological achievement is a new program that lets residents of Shibuya Ward in Tokyo apply for a residential certificate using LINE and pay with LINE Pay, marking the first use case of eKYC at the municipal government level in Japan. Soon to come is LINE DOCTOR, a new service scheduled to launch this year, will allow patients and doctors to communicate using LINE video chat, diminishing the burden of having to make physical visits.

DEV DAY also explored LINE’s service advancements for businesses. In July, LINE OA added voice and video calls to help businesses respond to customer inquiries easier, with plans to also add restaurant reservations later this year and to incorporate LINE Pay by the end of 2020. Moreover, LINE launched LINE MINI App this year to provide various services as web applications within LINE.

LINE’s Blockchain platform is another area where LINE has continued to make progress since 2018, with the launch of LINE Blockchain Developers earlier this year as a platform that provides an easy and efficient way for developers to build blockchain services based on LINE’s independently developed mainnet. “Blockchain guarantees reliability by algothrim,” said Seokho Yang, senior executive officer of LINE Platform Development at LINE Corp. “We aim to build an easy-to-use Blockchain designed for everyone.” See press release: 

Many more changes will be coming in the year ahead, too, but LINE will continue to work on “Closing the Distance” for all.


LINE DEVELOPER DAY Official Account:

LINE DEVELOPER DAY 2020 Official Website:

LINE Engineering: