Senior Backend Engineer (TypeScript / Web3)

About Us In partnership with Sony and SBI — two of Japan's largest companies — we are building the infrastructure to bring the world's assets on-chain: Strium , a next-generation DeFi L1 powered by a fully on-chain orderbook exchange, and Startale App , a consumer super-app. Distributed across Tokyo, New York, and Singapore; English-operating; built to a world-class standard. About the Role We are looking for a Senior Backend Engineer to take ownership of the backend systems powering StartaleApp and other products across the Startale ecosystem. This is a senior, hands-on engineering role for someone who can own complex backend systems end-to-end - from designing APIs and backend services, to building scalable data pipelines, managing databases, integrating blockchain infrastructure, and operating production systems under real-world load. We are looking for an engineer who thrives in a startup environment and is comfortable taking responsibility for any part of the backend stack depending on what the product needs. One month you may be building user-facing APIs, another month designing blockchain indexers, optimizing database performance, improving system reliability, or architecting entirely new backend services from scratch. Most importantly, we are looking for someone who has previously built and operated large-scale production systems serving real users at meaningful scale . You should have firsthand experience designing systems that handle high traffic, large datasets, reliability challenges, and the operational complexity that comes with running critical backend infrastructure in production. You should be excited by solving difficult engineering problems, building systems that scale, and owning critical infrastructure with a high degree of autonomy. You will work closely with product, infrastructure, and protocol teams to build reliable systems that power seamless user experiences across both traditional and blockchain-based applications. Because our core product is a Web3 wallet, we highly value engineers who understand how decentralized applications work in practice — not just at the protocol level, but also from the perspective of real-world user interactions with wallets, DeFi protocols, and blockchain-based financial systems. Key Responsibilities Take ownership of backend architecture and implementation across multiple products within the Startale ecosystem. Design, build, and maintain scalable production APIs and backend services used by customer-facing applications. Build and operate high-performance distributed systems capable of serving large user bases and handling significant production traffic reliably. Design backend systems with strong focus on scalability, fault tolerance, reliability, and long-term maintainability . Build and maintain data pipelines, background workers, asynchronous processing systems, and event-driven architectures . Build and maintain blockchain integrations and indexing systems that ingest, process, and serve on-chain data to internal services and user-facing applications. Design efficient database schemas, optimize complex queries, and ensure long-term scalability of data storage systems. Work across both Web2 and Web3 backend infrastructure , integrating traditional backend systems with blockchain protocols and decentralized infrastructure. Diagnose and solve complex production issues, performance bottlenecks, reliability problems, and scaling challenges. Build systems with strong observability, monitoring, alerting, and operational tooling. Continuously improve backend architecture, deployment pipelines, system reliability, and engineering practices. Move quickly, make sound technical decisions independently, and take ownership of delivering production-ready systems. Requirements Core Backend Engineering Extensive experience building and operating production backend systems in modern engineering environments. Strong proficiency in TypeScript and modern backend frameworks ( NestJS, Fastify, Express , or similar). Strong understanding of backend architecture, API design, service-oriented architecture, and distributed systems design. Ability to independently design and deliver complex backend systems with minimal oversight. Large-Scale Systems Experience Proven track record building and operating backend systems serving large numbers of users in production environments. Experience designing systems that operate reliably under high traffic, heavy workloads, and demanding production conditions . Strong understanding of performance optimization, scalability bottlenecks, concurrency, fault tolerance, and infrastructure reliability. Experience operating systems where uptime, consistency, and reliability directly impact end users. Strong operational mindset and experience handling production incidents and scaling challenges in live systems. Data & Infrastructure Deep expertise with PostgreSQL , including schema design, indexing, query optimization, migrations, and production database management. Experience building systems that process large amounts of structured or event-driven data. Strong understanding of observability, logging, monitoring, and service health management. Web2 + Web3 Engineering Experience building backend systems for modern Web2 applications . Experience integrating with blockchain infrastructure , node APIs, smart contracts, or decentralized protocols. Familiarity with blockchain indexing systems, event processing pipelines, or other on-chain data infrastructure. Good understanding of wallet architecture , transaction lifecycle, signing flows, and blockchain data models. Familiarity with DeFi protocols and blockchain-based financial applications , either as a developer or an advanced user. Strong Plus Experience building backend services in Go . Experience with Kafka, NATS, RabbitMQ , or similar messaging systems. Experience with blockchain indexing frameworks such as The Graph , Subsquid , or custom indexers. Experience deploying and operating services using Docker and modern CI/CD pipelines. Contributions to open-source backend, infrastructure, or blockchain tooling projects. Strong understanding of the DeFi ecosystem and hands-on familiarity with products such as decentralized exchanges, lending protocols, staking systems, bridges, or other on-chain financial infrastructure. Experience building or integrating backend systems that interact with DeFi protocols. What We Value We care less about specific technologies and more about engineers who can: Take ownership of complex technical problems from design to production. Work comfortably across different parts of the backend stack depending on what the product needs. Build systems that reliably serve large numbers of users and continue operating under scale and production pressure. Make pragmatic engineering decisions in fast-moving startup environments. Learn unfamiliar technologies quickly and adapt to changing product requirements. Why Join Us Build the core infrastructure powering StartaleApp and the broader Startale ecosystem. Work on technically challenging problems spanning backend engineering, distributed systems, and Web3 infrastructure . Join a highly technical startup environment where engineers have significant ownership and direct product impact. Work alongside world-class engineers building ambitious next-generation infrastructure. Competitive compensation, ownership opportunities, and a direct role in shaping the future of Web3 products.