Senior Full-Stack SaaS Engineer - React, TypeScript, and MySQL (PT-US)

We are seeking an experienced Senior Full-Stack SaaS Engineer to join our team, focusing on enhancing and supporting an established SaaS platform used by commodity trading companies. This platform plays a critical role in managing complex shipment operations, enabling customers to organize and classify shipping documents, extract structured data from unstructured files, and execute various shipment-related workflows efficiently. As part of our team, you’ll contribute to a high-volume, business-critical application, working within a mature codebase, and collaborating with our engineering team in San Francisco., * Contribute to the ongoing development and enhancement of a production SaaS application.

• Build and improve frontend functionality using React and TypeScript.
• Develop and maintain backend services and logic, leveraging TypeScript.
• Work with MySQL databases, handling queries, schemas, and data models.
• Add new product features and refine existing shipment-management workflows.
• Handle document-heavy processes, including classification, data extraction, and structured record management.
• Investigate and resolve bugs, implementing reliable and maintainable solutions.
• Navigate and effectively contribute to a large, mature codebase.
• Enhance application performance, scalability, reliability, and code quality.
• Participate in code reviews and collaborate closely with internal engineering and product teams.
• Communicate technical risks, dependencies, and progress clearly and effectively.

ReactTypeScriptMySQLCI/CD, English・Professional, * Strong professional experience with React for building production applications.

• Extensive experience in TypeScript across both frontend and backend development.
• Solid experience working with MySQL or similar relational databases.
• Proven track record of contributing to large-scale production codebases.
• Excellent debugging and problem-solving skills.
• Ability to understand and work within established architectural frameworks without unnecessary rewrites.
• Proficiency with Git-based development workflows and code reviews.
• Capability to work independently while integrating seamlessly with an existing engineering team.
• Strong product mindset with a keen attention to user and business impact., * Experience in building or maintaining B2B SaaS products.
• Familiarity with logistics, supply chain, shipping, trade operations, or document-management platforms.
• Experience with document classification, data extraction, OCR, or AI-assisted workflows.
• Understanding of workflow automation and business process software.
• Experience supporting applications with active enterprise customers and handling high data volumes.
• Familiarity with automated testing, CI/CD, cloud infrastructure, and production monitoring.
• Previous experience in a product-first startup or growth-stage software company.