Senior Backend Software Engineer

Software Engineer

Boundless Inc., part of Yahoo Inc (headquartered in the U.S.), is a trusted marketing and advertising partner empowering global companies to succeed in the Japanese market. With multilingual teams spanning key regions worldwide, we deliver end-to-end solutions driven by deep local insights and a global perspective.

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. We are currently embarking on the development of a next-generation system designed to diversify and scale our revenue streams. To fuel this growth, we are seeking a talented, entrepreneurial software engineer based in Japan. In this role, you will collaborate closely with the engineering team across both the U.S. and Japan to deliver high-impact technical solutions.

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 & AI-Augmented Thinkers: We value rapid experimentation and continuous learning. You actively look for ways to augment your engineering workflow using modern generative AI tools, moving quickly from trial to production.

Responsibilities:

• Architect, build, and optimize scalable software systems for our ads management platform on AWS using agentic AI-assisted development practices.
• Develop product features and internal tools that improve customer experience and engineering productivity.
• Partner with cross-functional stakeholders to design scalable, maintainable technical solutions.
• Maintain and evolve core platform components with a focus on reliability, performance, and scalability.
• Collaborate with the US-based team by working from 6:00 AM (JST) Tuesday to Friday; Monday follows regular working hours.
• This is primarily a remote position with occasional in-office meetings and team gatherings.

Qualifications:

• Bachelor's, Master's, or PhD in Computer Science or a related technical field.
• 8+ years of professional software development experience.
• Business-level proficiency in both Japanese and English.
• Strong proficiency in Java.
• Hands-on experience with agentic coding practices, prompt engineering, or structured interactions with AI coding assistants to streamline development workflows.
• Deep understanding of algorithms, data structures, object-oriented programming, concurrency, and distributed systems.
• Experience working in UNIX/Linux environments.
• Experience designing and developing RESTful APIs.
• Experience with relational databases such as MySQL, Oracle, or BigQuery.
• Experience with cloud platforms such as AWS (strongly preferred) and/or GCP.
• Experience with container technologies such as Docker.
• Excellent technical analysis, problem-solving, and communication skills.
• Proactive mindset with a strong sense of ownership.

Nice to Have:

• Familiarity with React.js and Node.js.
• Programming proficiency in Python.
• Experience in data science or machine learning.
• Proficiency in Chinese.

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 ( or call View phone number on click.appcast.io. 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.