Senior Software Engineer, Quality Engineering (SDET)

About the role

In partnership with SBI Group, we are building a next-generation decentralized exchange (DEX) aimed at bringing the majority of Japanese equities on-chain. Our goal is to create a secure, transparent, and high-performance trading infrastructure capable of supporting institutional volumes while remaining accessible to retail participants. The platform features a fully on-chain order book powered by a custom state transition function and consensus layer, purpose-built for low-latency, high-throughput trading.

As a Senior Software Engineer, Quality Engineering (SDET), you will own the engineering foundations of quality across the platform. Rather than simply writing automated tests, you will design and build the testing architecture, automation frameworks, developer tooling, CI/CD integrations, and AI-powered quality systems that enable the entire engineering organization to ship quickly and confidently.

You will work across backend services, frontend applications, blockchain integrations, and trading infrastructure to ensure correctness, reliability, and performance under real-world trading conditions.

This is a highly technical software engineering role focused on building quality systems, not performing manual testing. We are looking for engineers who enjoy building platforms, tooling, and automation that other engineers rely on every day.

Key responsibilities

Quality Engineering Platform

- Design, build, and evolve the company's quality engineering platform.
- Define testing architecture across unit, integration, contract, API, and end-to-end testing.
- Build and maintain reusable testing frameworks, shared libraries, fixtures, and developer tooling.
- Design reliable test data generation and management strategies that enable deterministic and repeatable testing.
- Continuously improve developer experience around testing and quality engineering.

AI-powered Quality Engineering

- Design and implement AI-assisted quality engineering workflows throughout the software development lifecycle.
- Build systems that leverage LLMs for automated test generation, test maintenance, failure analysis, root cause identification, and regression detection.
- Develop internal tooling that combines traditional automation with AI to improve engineering productivity and software quality.
- Continuously evaluate emerging AI technologies and integrate them into the team's quality engineering practices.

Test Automation & CI/CD

- Build comprehensive automated test suites covering APIs, backend services, frontend applications, and blockchain interactions.
- Integrate automated testing into CI/CD pipelines with fast feedback cycles and automated quality gates.
- Optimize test execution through parallelization, intelligent test selection, caching, and infrastructure improvements.
- Drive automation-first engineering practices across development teams.

Trading System Validation

- Validate the correctness of trading flows, order matching, execution paths, routing logic, fee calculations, and settlement.
- Verify consistency between backend services, blockchain state, and frontend behavior.
- Design robust regression suites protecting the platform's critical trading functionality.
- Ensure correctness under real-world market conditions and edge cases.

Infrastructure, Performance & Reliability

- Build and maintain containerized testing environments using Docker and modern infrastructure tooling.
- Design contract, integration, and end-to-end testing strategies for distributed systems.
- Develop automated load, stress, endurance, and resilience testing for high-throughput trading services.
- Validate system behavior during degraded conditions, network failures, timeouts, and infrastructure outages.
- Collaborate with engineering teams to improve system observability and accelerate production issue investigation.

Engineering Collaboration

- Work closely with Backend, Frontend, Blockchain, DevOps, and Product teams to improve overall system quality.
- Participate in architecture discussions to ensure systems are designed for testability and reliability.
- Drive quality engineering best practices across the organization.
- Mentor engineers on automated testing, testing architecture, and quality engineering principles.

Qualifications

Required Experience

- Ability to write clean, maintainable, production-quality software, not just automated tests.
- Experience building scalable automation frameworks and reusable testing libraries from scratch.
- 5+ years in SDET, Quality Engineering, Test Automation, or Software Engineering roles.
- Strong software engineering skills with JavaScript or TypeScript.
- Strong experience with modern end-to-end testing frameworks such as Playwright or Cypress.
- Strong experience testing APIs (REST, JSON-RPC, GraphQL, WebSocket, or similar).
- Experience integrating automated testing into CI/CD pipelines.
- Experience with Docker and containerized testing environments.
- Strong communication skills and the ability to collaborate effectively across engineering disciplines.

Nice-to-Have

- Experience building internal developer-productivity or quality-engineering platforms.
- Experience designing testing architecture for complex distributed systems (API, integration, contract, and E2E strategy).
- Experience designing and implementing performance, load, and reliability testing (k6, Artillery, Gatling, or Locust).
- Strong understanding of observability and production debugging (OpenTelemetry, Prometheus, Grafana, or Datadog).
- Experience debugging distributed systems across frontend, backend, APIs, databases, and infrastructure.
- Experience designing and managing reliable test data and testing environments.
- Experience testing complex transactional, financial, or high-throughput systems.
- Experience designing AI-assisted testing systems or integrating LLMs into QA workflows (test generation, failure analysis, regression detection, test maintenance).
- Experience testing DEXs, trading platforms, exchanges, or other financial systems.
- Familiarity with blockchain fundamentals, smart contracts, and on-chain flows; order books, AMMs, liquidity pools, routing, and execution.
- Experience with Kubernetes and cloud-native infrastructure.