Senior Developer Exclusive job

【ポジションについて】

We are seeking a Senior Developer who is equally comfortable sitting with the customer to define real business test scenarios and writing, debugging, and extending application code across Next.js / React front-end and back-end services. The role owns the bridge between customer business use cases and engineering reality - turning ambiguous requirements into clear, executable test scenarios, and getting hands-on in the codebase when investigation, fixes, or test tooling are needed.

【職務内容】

- Engage directly with the customer to elicit, clarify, and document business use cases, acceptance criteria, and test scenarios; translate business language into testable engineering requirements.

- Design and execute end-to-end test strategy across functional, integration, regression, performance, and user-acceptance testing.

- Build and maintain automated test suites - unit, integration, end-to-end (e.g., Playwright, Cypress, Jest) - across front-end and back-end layers.

- Develop and debug full-stack code in Next.js / React (TypeScript) and back-end services to investigate defects, build test harnesses, mock services, and fixtures.

- Lead UAT (User Acceptance Testing) sessions with customer stakeholders; capture, triage, and reproduce defects with clear evidence.

- Integrate testing into CI/CD pipelines; enforce quality gates and ensure release readiness.

- Coordinate with the Solution Architect and Technical Lead on test scope at phase boundaries and on quality criteria for code freeze and trial release.

- Apply AI coding tools (e.g., Claude Code, GitHub Copilot) responsibly for test generation, code investigation, and accelerating debugging - with sound judgment on AI-generated output.

- Operate within a RAD (Rapid Application Development) and spec-driven development workflow - ship test coverage in iterations alongside evolving specs.

FDE delivery model:

This is a Forward Deployed Engineer (FDE) role – the Senior Developer embeds within a client environment, owns the bridge from business use case to shipped, tested code, and remains hands-on through build, UAT, and trial release. The candidate is expected to operate as a true FDE (Lv.2 and above).

FDE = Forward Deployed Engineer:

An engineer who embeds with the customer and owns delivery end-to-end (design → build → ship → improve), then templatizes reusable assets and enables scalable delivery across teams. In a recent engagement, the embedded FDE pod achieved ~60% AI-generated code at Grade A, reduced bug-fix MTTR from days to under 4 hours, and operated without a separate project-manager layer. Architecture decisions (the ADR) remain human-owned and accountable while AI accelerates the build.

登録資格

【Must】

- 7+ years in software development and / or test engineering, with at least 3 years in customer-facing or consulting environments.

- Proven ability to communicate with business stakeholders in their language and translate use cases into test scenarios.

- Hands-on full-stack development experience: Next.js / React (TypeScript) on the front-end and a back-end language such as Node.js / Python.

- Strong debugging skills across browser, network, API, and back-end layers - able to investigate defects without depending on developers.

- Practical experience with test automation frameworks (e.g., Playwright, Cypress, Jest, Vitest, pytest) and API testing (Postman, REST/GraphQL).

- Experience embedding tests in CI/CD (e.g., GitHub Actions, GitLab CI) and working with Git-based workflows.

- Hands-on experience using AI coding tools (e.g., Claude Code, GitHub Copilot, Cursor) for test authoring and debugging.

- Familiarity with agile / sprint-based delivery; experience running UAT and bug triage with customer stakeholders.

- Business-level Japanese and English.

FDE (Forward Deployed Engineer) requirements:

- True hands-on, end-to-end ownership (build -> test -> ship): a Forward Deployed Engineer (FDE Lv.2 and above) comfortable shipping and debugging production code on-site, not only writing test cases.

- Willingness and ability to embed on-site with the customer in a relationship-driven B2B context, owning the business-to-engineering bridge end-to-end.

【Nice to have】

- Experience testing AWS-hosted applications and integrations with enterprise content platforms (Box, SharePoint, or equivalent).

- Performance and load testing experience (k6, JMeter, Locust).

- Experience in construction, engineering, or other document-heavy enterprise domains.

- Cross-market delivery experience (US, Japan, APAC).

FDE (Forward Deployed Engineer) nice-to-have:

- Experience working in a single-owner FDE pod with no separate PM layer.

- Track record achieving ~50%+ AI-generated test / production code at high quality (Grade A).

- Experience reducing bug-fix MTTR from days to hours via in-app capture -> AI auto-fix workflows.