Masahiro Hanawa

Senior Full-Stack Engineer with 12+ years of experience building SaaS platforms, business applications, and customer-facing products.

My primary expertise is TypeScript across the entire stack, including React, Next.js, Node.js, Express, and React Native. I have worked on projects ranging from early-stage MVPs to large-scale production systems, with a strong focus on maintainability, performance, and pragmatic architecture.

I enjoy solving complex business problems and taking ownership from design to deployment. My experience includes multi-tenant SaaS platforms, payment integrations, mobile applications, API design, cloud infrastructure, and AI-powered features using modern LLM technologies.

Recent work includes:

• Building and maintaining React Native applications used in production environments

• Designing scalable backend services with Node.js and PostgreSQL/MongoDB

• Implementing AI-assisted workflows and LLM integrations

• Refactoring and modernizing legacy systems to improve reliability and development speed

• Setting up CI/CD pipelines, Docker-based deployments, and cloud infrastructure

I value clear communication, strong TypeScript typing, observability, and incremental delivery. Rather than pursuing unnecessary complexity, I focus on building solutions that are easy to understand, maintain, and extend.

Based in Berlin and available for remote projects across Europe and internationally.