About LINE Corp.

At 83 million domestic users, or 65% of the population, LINE is Japan’s most popular messaging application. It is also popular throughout Asia, boasting approximately 186 million users globally.

Build Reliable Systems at Scale

You’ll have the opportunity to work on systems that are both highly scalable and reliable. For example, we use Apache Kafka to process over 360 billion messages a day, while keeping the cluster’s availability nearly 100% and less than 10 milliseconds response time.

International Support

About 40% of our engineers are non-Japanese. There are teams that don’t require any Japanese abilities, and for those wanting to improve their Japanese skills, we offer Japanese lessons.

Room to Grow

We’re a fast growing organization that’s full of young, enthusiastic engineers. We offer a leveling system with both individual contributor and management tracks, so regardless of how you wish to improve your skills, there’s room for you to grow within the company.

Healthy Work/Life Balance

We offer flextime so that you can set a schedule that is best for you. We encourage our employees to take vacations, and it’s not uncommon for some employees to take off several weeks in a row.

Our response to COVID-19

In response to COVID-19, we’ve introduced a number of initiatives to support our users in Japan and around the world. These include working with Japan’s Ministry of Health, Labour and Welfare to offer remote consultations with medical professionals, and offering free one-on-one counseling for people who are suffering from anxiety and stress stemming from COVID-19.

During this crisis, we’re advising all our employees to work from home, moved to conducting recruitment interviews over video chat, and have shifted all contracts to electronic form to allow those who handle contracts to work from the safety of their homes.

After COVID-19 comes to an end, we plan to offer a work style that combines working from home and coming to work. More details are available in Japanese.

About the position

Our Mission

Our team works on features and under the hood improvements for the Android and iOS clients of the LINE messaging app, doing our part to make LINE Corp’s mission of “Closing the Distance” into a reality. The app’s place in users’ daily lives means we go beyond simply developing new features: we strive to provide a stable application by constantly working on improvements.

About the Team

In addition to LINE’s other domestic offices, our team collaborates with colleagues in South Korea, Taiwan, Vietnam, and other overseas offices. With our members hailing from over 15 different countries, our Japan team itself is also cosmopolitan. We mainly use English for documentation and chats, and also communicate verbally in English at times. We use GitHub’s Pull Requests to review each other’s code and hold study sessions.

Team members actively contribute to OSS and are encouraged to attend and/or present at external conferences and workshops. Some of our members’ recent achievements include contributions to Swift, OSS for iOS and Android, and presenting at DroidKaigi, iOSDC, and AltConf.


Leverage your expertise to develop and improve LINE’s Android and iOS clients. Collaborate with planners, UI/UX designers, data scientists, business development teams, and other stakeholders.

Who You Are

You take initiative and go beyond your current role to boost team productivity through codebases, improving tools, and helping team members expand their knowledge. You endeavor to contribute quality output by proposing improvements for plans, development specifications, and tests.

Current Product Phase/Exciting Challenges/Opportunities

You’ll be involved in the development of the LINE client app, which is used by hundreds of millions of people in Japan and abroad (particularly in Asia). This means you’ll have the opportunity to be a part of the planning and development of an app that is popular both domestically and globally. Additionally, our codebase has grown massively in size since the LINE app was launched eight years ago. You’ll work on improving the codebase’s internal structure as well as the performance and UX of the app itself. Through code reviews that let developers learn and improve from one another, automated CI testing, and other workflows we’ve created, we ensure all the development work we do is sustainable.

Tools/Development Environment

Devices used in development:

MacBook Pro, iMac 5K, etc. (recommended configuration for development: Core i9 or better, over 32GB memory, over 1TB SSD) More than one device can be loaned upon request. Developers are also provided with extra monitors and standing desks.


Github Enterprise, JIRA, Confluence, LINE, Slack, Jenkins Use Thrift IDL to collaborate with other teams Android: Java + Kotlin (mixed project), Gradle, Kotlin coroutine, RxJava2, Feature Flag systems, etc. iOS: Swift + Objective-C (mixed project), Fastlane, XcodeGen, Bazel, etc.

Career Path

We have a leveling system that assigns you a “career level” based on performance expectations.

You can choose from three career paths after joining.

Individual Contributor: As an individual engineer, you’ll build on your technical skills and contribute to the team with your designs, codes, and reviews. Tech Lead: You will lead a small to medium-sized team of engineers in development and help them strengthen their technical skills. Engineering Manager: You will manage a medium to large-sized team of engineers and endeavor to maximize the team’s output. You’ll also have the opportunity to move teams when internal job postings open up once a year.


Preferred Qualifications

Meet LINE Corp.'s Developers

Growing a career in Japan

with Matthew Bailey

Starting as a server side engineer at LINE, Matt is now a software development manager. He shares his experiences of finding a job in Japan, and gives tips on how you can be successful at landing one too.

Read his story...

Joining LINE from overseas

with Li Liu

Li was working in Toronto when he was recruited to join LINE as a principal engineer. He tells his story of relocating to Japan.

Read his story...

Joining LINE as a QA Engineer

with Swapnali Koli

Swapnali had been working at a Japanese company as a QA Engineer. Looking for a new challenge, she joined LINE, where she’s led their private cloud API automation project.

Read her story...

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