Senior Fullstack Engineer

Job Description

Appealing Points

• Technical Leadership Opportunity: Take ownership of architectural decisions, ensuring scalability, reliability, and security while shaping the company’s technology roadmap and mentoring other engineers.
• Full-Stack Innovation at Scale: Work across modern technologies—from backend microservices in Java, Kotlin, or NodeJS to front-end development using React, Angular, or Vue.js—building robust, user-centered web applications.
• Collaborative and Growth-Oriented Culture: Engage in mentorship, peer reviews, and cross-functional collaboration, staying ahead of emerging tech trends to continuously evolve both the product and your technical expertise.

Annual Salary: 8 Million Yen and above

Responsibilities:

• Architectural Leadership: Participate in and lead architectural discussions, contributing to the overall technology roadmap and ensuring the scalability, reliability, and security of our systems.
• End-to-End Development: Design, develop, and maintain high-quality, scalable web applications across both front-end and back-end, utilizing modern frameworks and best practices.
• Backend Expertise: Develop and maintain resilient RESTful APIs and microservices using programming languages such as Java, Kotlin, or NodeJS, and related frameworks (Spring, ExpressJS).
• Frontend Prowess: Craft intuitive, responsive, and accessible user interfaces using modern JavaScript frameworks like React (including latest frameworks like Remix), Angular, or Vue.js, focusing on an exceptional user experience.
• Database Management: Design, optimize, and maintain database schemas and queries for performance and scalability using relational (e.g., MySQL, PostgreSQL) and/or NoSQL (e.g., Cassandra) databases.
• Cross-functional Collaboration: Partner closely with product managers, designers, QA, and DevOps teams to gather requirements, provide constructive feedback, and ensure successful product delivery.
• Code Quality & Best Practices: Write clean, efficient, well-tested, and reusable code. Conduct thorough code reviews to maintain high quality standards and share knowledge within the team.
• Cloud & DevOps: Deploy and manage applications on cloud infrastructure platforms like Kubernetes (K8s), collaborating with DevOps to streamline deployment, monitoring, and scaling processes.
• Mentorship & Growth: Provide guidance and mentorship to junior engineers, fostering their growth and development, and contributing to a collaborative and continuous learning environment.
• Innovation & Trends: Stay abreast of the latest industry trends, technologies, and best practices across the full web development stack (front-end, back-end, databases, cloud), and proactively apply them to enhance our applications.
• Security & Compliance: Implement robust security measures to protect data and ensure compliance with industry standards across all layers of the application.

Job Qualifications:

• Bachelor's degree in Computer Science, Engineering, or a related field (or equivalent work experience).
• 10+ years of progressive experience in software development, with a significant portion in full-stack web applications.
• Minimum 3 years of experience operating in a Senior Engineer role, demonstrating technical leadership and mentorship.
• Strong proficiency in programming languages such as Java, Kotlin, or NodeJS, with proven experience in designing, developing, and maintaining robust REST APIs and microservices.
• Strong proficiency in HTML, CSS, and JavaScript (ES6+), with extensive experience in modern JavaScript frameworks like React (including frameworks like Remix), Angular, or Vue.js. Familiarity with state management libraries (e.g., Redux, MobX) is essential.
• In-depth knowledge of database technologies (e.g., MySQL, PostgreSQL, Cassandra) and proven experience in designing schemas and optimizing queries for performance.
• Solid understanding of software development principles, design patterns, data structures, algorithms, and best practices across the full-stack.
• Excellent analytical, problem-solving, and decision-making skills, with the ability to thrive in a fast-paced, collaborative environment.
• Strong communication and interpersonal skills, with the ability to effectively articulate complex technical concepts and solutions to both technical and non-technical stakeholders.
• Experience with Agile development methodologies.

Preferred qualification:

• Master's degree in Computer Science, Engineering, or a related technical field.
• Demonstrated experience with distributed systems and microservice architectures at scale.
• Proven track record in performance tuning and optimization across both frontend and backend systems.
• Experience designing and implementing scalable and maintainable full-stack architectures.
• Hands-on experience with monitoring, logging, and tracing tools (e.g., Prometheus, Grafana, ELK stack, Jaeger).
• Understanding of common architectural patterns for building resilient and observable applications.
• Experience with CI/CD pipelines and automated deployment processes.
• Familiarity with infrastructure as code (IaC) tools (e.g., Terraform, CloudFormation).
• Experience with security best practices for web applications and APIs (OWASP Top 10).
• Experience mentoring junior engineers or leading small technical initiatives.
• Active participation in open-source projects or contributions to the wider tech community

Languages:

• English (Overall - 3 - Advanced)

About Company 

The largest eCommerce company in Japan, and the third-largest eCommerce marketplace company worldwide. The organization provides a variety of consumer and business-focused services including e-commerce, e-reading, travel, banking, securities, credit card, e-money, portal and media, online marketing, and professional sports.  The company is expanding globally and currently has operations throughout Asia, Western Europe, and the Americas. 

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No smoking indoors allowed
Designated smoking area