Full-stack Engineer

• Analyze, debug, and resolve software bugs and security vulnerabilities across diverse codebases.
• Implement features and improve existing functionality using Python 3, Java, Rust, Go, C++, or TypeScript.
• Refactor legacy code to improve maintainability, security, and performance.
• Conduct codebase audits, penetration testing, and security assessments to identify and mitigate risks.
• Contribute to backend development and optimize applications for scalability and security.
• Apply secure software development practices and assess potential security risks.
• Document technical findings and recommend practical improvements.
• Provide real-world engineering and cybersecurity insights to improve AI training datasets.

Cybersecurity Specialist, Software Engineering – AI Projects

• Use Claude, Cursor, and Pi AI agent as primary mechanisms for building features
• Translate product briefs into working full-stack software from design through deployment
• Maintain prompt logs for significant features, including AI failures and corrective steering
• Write and critically stress-test AI-generated test suites
• Identify hallucinations, logic gaps, and edge cases before production
• Participate in pod rituals and share new AI techniques with the team
• Operate as the primary delivery engine within an autonomous pod
• Build production-ready software at high velocity while verifying AI-generated output

Product Engineer

• Facilitate Process Hazard Analyses (PHA), Layers of Protection Analysis (LOPA), and Dust Hazard Analyses (DHA) for routine revalidations and capital projects
• Mentor site-based facilitators
• Serve as a process safety subject matter expert, providing technical guidance on risk identification, evaluation, and mitigation
• Guide sites in applying and interpreting Recognized and Generally Accepted Good Engineering Practices (RAGAGEP)
• Partner with site leadership, engineering, and EHS teams to improve process safety performance
• Lead initiatives to reduce risk associated with high-hazard materials, technologies, and operations
• Support and participate in audits, compliance reviews, and internal or external process safety assessments
• Contribute to process safety incident investigations, including incident classification, root cause analysis, and enterprise trend analysis
• Support development and deployment of corporate process safety training programs
• Support sites with implementation of machine safety programs, systems, processes, and equipment upgrades
• Monitor site machine safety performance and troubleshoot safety-related issues
• Identify and promote best practices for machine safety design, operation, and maintenance
• Provide technical guidance and oversight during procurement, fabrication, and installation
• Support development and continual improvement of corporate engineering standards for machine safety and mechanical design

Lead Engineer, Process Safety and Risk Management, Machine Safety

• Design, build, and ship features critical to growing the Japan market, including payment/payout methods, logistics integrations, seller onboarding and compliance, and locally tailored buyer and seller experiences
• Own technical strategy for Japan by partnering with the Japan GM to translate market needs into a roadmap, decide what to build and how, and own trade-offs
• Determine how Japan-market work fits into Whatnot’s global architecture
• Lead execution across multiple workstreams with engineers and cross-functional partners in Japan and globally
• Establish the technical foundation, architecture, patterns, quality bar, and culture for Whatnot’s engineering presence in Japan
• Act as the technical leader of the Japan engineering presence and bridge between the Japan business and global engineering organization

Full-stack Engineer jobs in Japan

Cybersecurity Specialist, Software Engineering – AI Projects

Product Engineer

Lead Engineer, Process Safety and Risk Management, Machine Safety

Staff Software Engineer