Senior/Lead Fullstack Engineer

Top 3 reasons to join us

• Flexible working time
• Hybrid working
• Global environment

Job description

Itviec’s client is seeking a highly skilled Senior Fullstack Engineer to drive the development of their cutting-edge SaaS Platform. The Senior Fullstack Engineer will work closely with cross-functional teams to build and scale a high-performance web application that handles complex business logic and user interactions. The ideal candidate will have a strong technical background across the full stack—from database design using domain-driven design principles to optimizing frontend performance—coupled with the ability to leverage modern web technologies and architectural patterns.

Key Responsibilities:

• Lead the end-to-end design, development, and maintenance of our core SaaS platform, guaranteeing top-tier availability and low latency.
• Build, scale, and maintain clean GraphQL APIs following a schema-first approach and domain-driven design principles.
• Work daily across a modern TypeScript ecosystem (Next.js, NestJS, React) to handle intricate enterprise workflows and user interactions.
• Collaborate seamlessly with cross-functional, multi-national teams to validate, implement, and deliver impact-driven features.
• Participate actively in rigorous code reviews to safeguard high-quality coding standards and write detailed technical documentation (ADRs, Design Docs, Runbooks).
• Participate hands-on in daily product operations, including on-call support, incident responses, troubleshooting, and strategic architectural decisions.

Your skills and experience

Core Requirements (Must Have):

• Minimum 7 years of professional, hands-on experience in full lifecycle web application development.
• High proficiency in statically typed languages like TypeScript or Rust, with verified full-stack experience (both frontend and backend).
• Solid frontend development expertise, specifically leveraging React (Hooks, Context, State Management) and Next.js (SSR/SSG).
• Deep backend engineering experience with Node.js and GraphQL, including schema design, resolvers, and resolving N+1 query optimization problems.
• Hands-on database design and performance optimization experience utilizing PostgreSQL and modern ORMs like Prisma.
• Strong experience building, testing, and maintaining secure RESTful and GraphQL APIs using modular architecture and domain-driven design.
• Solid English communication skills (~B1 level or higher), enabling smooth reading, writing, and verbal technical discussions with a global team.

Preferred Qualifications (Nice to Have):

• Familiarity with advanced patterns and architectures such as BFF (Backend for Frontend), clean architecture, microservices, and DDD.
• Hands-on exposure to cloud infrastructure platforms (GCP, Kubernetes) and CI/CD automated pipelines (GitHub Actions).
• Prior experience developing complex B2B SaaS products, enterprise-grade business logic, or large-scale distributed systems across multiple engineering teams.
• Experience working within Agile/Scrum frameworks and building security-conscious web applications.

Why you'll love working here

ITviec's client – a leading Japanese B2B technology platform in the manufacturing and supply chain optimization domain – is seeking Senior Fullstack Engineers to join a digital transformation revolution for a trillion-dollar industry. Here, we do not just hire “code worker”, we look for true Product Engineers.