From Malaysia to Tokyo, Jian Min Chai, OSS Architect at Rakuten Symphony, has turned a passion for systems into a career in cutting-edge telecom.
Originally from Malaysia, I moved to Japan around the age of 18 to pursue engineering studies. I completed both my bachelor’s and master’s degrees here - my master’s was at the University of Tokyo. I studied electrical and electronic engineering, but I've always been drawn to computer systems, and gradually, I became more focused on software.
I joined Rakuten Mobile in April 2020 as a new graduate. At the time, I was looking for a Japanese tech company with a strong international presence - and Rakuten stood out. It offered an environment where I could use both my technical and language skills, and the global mindset here really appealed to me.
When Rakuten Symphony launched, it felt like a natural progression. The team was evolving rapidly, and there was a real opportunity to build something new - this time with a broader, more global scope. I was excited by the chance to apply the insights from Rakuten Mobile in a more scalable and impactful way. What makes Rakuten Symphony particularly unique is the diversity of thought and the pace of innovation. It’s not just about maintaining systems - it’s about creating new ones, collaborating across borders, and constantly evolving. That combination of challenge and learning is exactly what I am looking for.
As an OSS Architect, my job is all about problem-solving and systems design. I support our teams by helping them overcome technical issues and finding the best solutions. Whether it's reviewing logs, debugging escalations, or suggesting how to integrate different vendor platforms, I'm often the bridge between challenges and resolutions. On a typical day, I’ll start by checking dashboards, especially if we had overnight deployments. Then I dive into team meetings to discuss designs and potential improvements, write or review code, and collaborate with both our Japan and India teams. The role is hands-on and dynamic, which I find incredibly rewarding.
Definitely the speed! I am genuinely impressed by how smoothly cross-functional teams align and move together. Whether it's engineers, product leads, or support teams, everyone is focused on delivering real outcomes. The speed of execution, combined with that sense of shared purpose, creates an energizing work culture where innovation doesn’t get stuck in process - it moves forward, fast.
I remember one case where we were asked to implement a monitoring feature: the entire process, from the initial request to full deployment in production, was completed in under two weeks. That kind of turnaround is rare anywhere, but it’s especially impressive in a company operating at this scale. It showed me how quickly things can happen when the right people are empowered to act!
For me, the best days are when I get to focus fully on coding - when I can really dig into the technical challenges and spend time building something meaningful. Whether it's designing a cleaner system or refining an integration, I enjoy that sense of flow and progress that comes from solving problems with code.
Rakuten Symphony gives me the space and trust to do that. The support from the team, the collaborative spirit, and the clear sense of purpose all create an environment where I can stay focused and creative. Those days remind me of why I got into this field in the first place - and why I enjoy coming to work every day.
I really like the ideas in Daniel Kahneman’s book Thinking, Fast and Slow. It explores how we make decisions - both instinctively and rationally. That dual approach really resonates with me. In our work, there are times we need to act quickly, relying on experience and intuition to address an urgent issue. But once the pressure eases, it’s just as important to slow down, dig deeper, and analyze the root cause carefully.
That balance between fast reactions and thoughtful analysis helps me stay grounded and effective, especially when I am working on complex systems or navigating production incidents. It’s a mindset I try to bring into my day-to-day approach.
I love hiking and running. I try to go hiking at least once a month, usually somewhere around the Kanto region. I actually have a Japanese hiking guidebook that I use to pick new trails. My favorite hike so far has probably been Mt. Fuji - even though I reached the summit during a typhoon! That made it the hardest hike too.
If you're just starting your career at Rakuten Symphony, like I did, it helps to approach things with curiosity and openness. Don’t be afraid to ask questions or reach out to people. The more you engage, the more you’ll learn. Symphony is a place where initiative is valued, and you'll find many chances to take on meaningful challenges early on.
Right now, I’m focused on deepening my skills as a software architect, especially around designing scalable and efficient systems. There’s still a lot I want to explore, particularly in how to build platforms that can grow with the needs of the business. I’m also really interested in how AI can support that journey. We’re already seeing how large language models can assist with automation and streamline tasks like code generation. I’d love to better understand how we can integrate AI into the architecture itself to create smarter, more adaptable systems.
