Senior Software Engineer (LINE API / LIFF App)
About Our Team
As an integral part of Yahoo Inc. and Boundless Inc., our team develops a sophisticated search and display advertising management platform tailored for global clients expanding into the Japanese market. We provide a comprehensive suite of tools for automated high-volume ad data management and leverage cutting-edge AI to streamline complex business workflows.
To accelerate our expansion, we are currently embarking on the development of next-generation systems designed to diversify and scale our revenue streams. A core initiative in this expansion focuses on leveraging LINE – Japan’s dominant messaging ecosystem – to build innovative, revenue-generating product features.
To fuel this growth, we are seeking a talented and creative Senior Software Engineer based in Japan with proven experience using the LINE Messaging API and LIFF (LINE Front-end Framework). In this role, you will collaborate closely with cross-functional teams across both the U.S. and Japan to architect high-impact solutions, build scalable messaging workflows, and unlock new revenue channels for our business.
Our Culture
We operate as an agile, independent startup within Yahoo with unique business, spanning seven global locations with a remote-first and highly connected mindset. We seek engineers who are:
- Self-Driven Owners: You thrive on autonomy, taking full ownership of your work from concept to production.
- Global Collaborators: You excel at bridging distances, prioritizing proactive communication and seamless teamwork.
- Agile Thinkers: We value experimentation and iteration—we try fast, fail fast, and share what we learn to solve complex challenges.
Responsibilities:
- Architect, develop, and optimize end-to-end systems for LINE messaging services and applications on AWS, leveraging agentic AI coding practices.
- Engineer new product features and operational tools to address the evolving needs of our global clients.
- Partner with cross-functional stakeholders to identify user pain points and translate business requirements into robust technical specifications.
- Deeply understand the architecture and implementation details of existing platforms to ensure seamless integrations and ongoing system health.
- Continuously enhance core components of the whole ecosystem for improved performance and scalability.
Work Schedule & Location
- Overlapping Hours: Because engineering team members are based in both Japan and the United States, this role requires working from 6:00 AM JST (Tuesday through Friday) to maintain sufficient overlapping hours with U.S.-based colleagues. Mondays follow standard local working hours.
- Work Arrangement: This position is primarily remote (work-from-home), with occasional in-office meetings or team gatherings in Japan.
Qualifications:
Core Requirements:
- Bachelor’s, Master’s, or PhD in Computer Science, or a related technical field.
- 8+ years of professional experience in software development.
- Active practice with – or a strong willingness to adopt – agentic AI coding techniques and workflows
- Deep experience in development using LINE messaging API, LIFF (LINE Front-end Framework), and LINE MINI App ecosystems.
- Hands-on experience with LINE SDKs, user authentication flows, and cloud application hosting on AWS or GCP
- Strong programming proficiency with Java, JavaScript, and TypeScript
- Deep understanding of algorithms and data structures
- Hands-on experience with relational databases and big data stores (e.g., MySQL, Oracle, or BigQuery)
- Experience with other LINE APIs is a plus
- Deep expertise in object-oriented programming, concurrency, distributed systems, and UNIX/Linux environments.
- Experience with design and development using REST APIs
- Experience with containerization technologies, such as Docker
Soft Skills & Communication:
- Excellent technical analysis, problem-solving, and communication skills.
- Proactive mindset with a strong sense of end-to-end ownership
- Business level proficiency in both Japanese and English (spoken and written)
Boundless is proud to be an equal opportunity workplace. All qualified applicants will receive consideration for employment without regard to, and will not be discriminated against based on age, race, gender, color, religion, national origin, sexual orientation, gender identity, veteran status, disability or any other protected category. Yahoo will consider for employment qualified applicants with criminal histories in a manner consistent with applicable law. Yahoo is dedicated to providing an accessible environment for all candidates during the application process and for employees during their employment. If you need accessibility assistance and/or a reasonable accommodation due to a disability, please submit a request via the Accommodation Request Form (www.yahooinc.com/careers/contact-us.html) or call +1.866.772.3182. Requests and calls received for non-disability related issues, such as following up on an application, will not receive a response.
At Boundless, we know that diversity makes us stronger. We are committed to a collaborative, inclusive environment that encourages authenticity and fosters a sense of belonging. We strive for everyone to feel valued, connected, and empowered to reach their potential and contribute their best.
Yahoo has a high degree of flexibility around employee location and hybrid working. In fact, our flexible-hybrid approach to work is one of the things our employees rave about. Most roles don’t require specific regular patterns of in-person office attendance. If you join Yahoo, you may be asked to attend (or travel to attend) on-site work sessions, team-building, or other in-person events. When these occur, you’ll be given notice to make arrangements.
If you’re curious about how this factors into this role, please discuss with the recruiter.