We are looking for a Staff Fullstack Engineer to join our high-performing team working at the intersection of our Realtime and Personalization products. This is a pivotal moment for our platform: you will help drive the technical direction as we build an AI-native system, developing true, industry-leading systems that empower marketers to build in new ways.
In this role, you will act as a high-level individual contributor and technical anchor within a squad-based model. While your core expertise may lay in either complex frontends or robust distributed backend systems, you possess the architectural vision to design and mentor others across the full stack. This is a hands-on, high-impact role. You will work out of our Tokyo office three days a week, collaborating directly with product managers and designers to ship features that have a tangible impact on our customers’ ability to generate value from their data.
Responsibilities
-
Drive the end-to-end technical architecture for our product features. You will make high-stakes technical decisions that balance speed of delivery with long-term maintainability.
-
Ensure a focus on outcomes and ensure your squad is unblocked whether it is frontend or backend code and provide technical guidance to your peers.
-
Deeply focus on design across the entire stack. You will weigh in on how React applications should be structured even if you are working on the backend to ensure consistency across the entire stack and unblock every engineer in your squad.
-
Partner with Product Managers and Engineering Managers in a squad model to deliver projects on time. You will break down complex requirements into executable engineering tasks. You may serve as a tech lead for a squad.
-
Elevate the engineers around you. You will mentor Senior and mid-level engineers, modeling best practices in code review, design patterns, and operational excellence.
-
Build with a mind toward scalability, observability, and security. You will join the on-call rotation and treat production operations as a first-class citizen.
Requirements
-
8+ years of software engineering experience, with a strong track record of shipping complex products.
-
Deep proficiency in backend development (experience with Ruby, Go, Java, or Kotlin is preferred). You understand database design, and API scalability and as a strong bonus have dealt with distributed systems or LLMs in production.
-
You have strong architectural knowledge of the React ecosystem. You may prefer backend work, but you understand how to build a frontend architecture that is modular and testable and are able to mentor engineers in React best practices.
-
You thrive in agile, collaborative environments. You are a driver—you identify blockers and remove them.
-
Business-level English proficiency is required. You can effectively communicate complex technical concepts to non-technical stakeholders.
Nice to haves
While not specifically required, tell us if you have any of the following.
-
Experience building or integrating Generative AI/LLM solutions into production workflows, especially with agents.
-
Experience with Ruby on Rails is a significant plus.
-
Experience with distributed systems.
-
Experience working in global teams, coordinating with engineers in different time zones.
.png){kind=small}
