Masaya Tsuji
@masayatsuji
Software engineer specializing in backend systems and applied AI (LLMs/CV).
What I'm looking for
I am a software engineer with 6+ years building frontend, backend, and applied AI systems for healthcare, logistics, manufacturing, e-commerce, and enterprise SaaS.
I architect and deliver production-ready LLM services, RAG pipelines, and efficient ML inference systems, improving latency, reliability, and accuracy across multiple products.
I have hands-on experience optimizing ML pipelines (ONNX Runtime, TensorRT), integrating AI into existing services, and shipping full-stack features using FastAPI, Node.js, C#/.NET, and React.
I emphasize observability, testing, documentation, and developer experience to reduce defects and onboarding time while enabling scalable deployments for multi-tenant customers.
Experience
Work history, roles, and key accomplishments
Software Engineer
MakEntWin
Apr 2024 - Present (1 year 5 months)
Architected LLM-powered FastAPI services and RAG pipelines that cut manual ticket handling by 30% and reduced time-to-answer from 1.2 to 0.6 minutes while lowering P95 latency by 40% and error rates by 25%. Integrated AI endpoints into C#/.NET services, reducing integration defects by 35% and enabling phased rollouts for 20+ client tenants.
Software Engineer
Viso.ai
Oct 2023 - Mar 2024 (5 months)
Optimized ML inference by porting Python to C++ and using ONNX Runtime with TensorRT to boost throughput to 30 FPS and improve performance by ~50%, and designed a counting algorithm that raised accuracy by 20%. Introduced unit testing and validation into the ML pipeline to improve stability and maintainability.
Full-stack Developer
Woventeams
Jan 2021 - Aug 2023 (2 years 7 months)
Refactored React/Redux into reusable hooks reducing bundle size 25% and improved LCP to 1.9s; built Flask REST APIs and resilient frontend integrations that reduced client-visible failures by 30% and improved data freshness SLAs to <2 minutes, increasing weekly active users by 22%.
Frontend Developer
Freelancer
Jan 2019 - Dec 2020 (1 year 11 months)
Delivered React patient portals for clinics that increased self-service usage by 35% and reduced call-center volume by 25%; launched e-commerce storefronts that improved conversion by 18% and mobile checkout speed by 30% while creating a 30+ component UI library to cut build time by 40%.
Education
Degrees, certifications, and relevant coursework
University of Ljubljana
Bachelor of Multimedia, Multimedia
2018 - 2025
Pursuing a Bachelor of Multimedia at the University of Ljubljana within the Faculty of Computer and Information Science / Faculty of Electrical Engineering, coursework focused on multimedia and computing fundamentals.
Tech stack
Software and tools used professionally
Availability
Location
Authorized to work in
Job categories
Skills
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