Joined in August 2026 as a Software Engineer on the Applied Team, bringing AI research into real-world applications.
Available for freelance & contract work Yuya Mitsuboshi
@MITSUBOSHIFrom build to operational stability — a tech lead who moves the business forward with systems
Across regulated industries — healthcare, payments, and tax compliance — I have worked on web application development, data infrastructure, delivery systems, quality assurance, and AI workflows. I focus on building systems that keep running rather than one-off fixes, driving incident response and technical-debt elimination by redesigning operations themselves.
01
About
I am a software engineer and tech lead based in Japan. I specialize in taking projects from the development phase through to operational stability, with a track record in heavily regulated domains such as healthcare, payments, and tax compliance.
My strengths lie in observing and deconstructing business workflows, then redesigning them with a combination of human judgment and AI automation — and in quantifying incident impact with SQL, building monitoring, and escalating findings into organizational investment decisions. I am a T-shaped engineer: deep specialization (microservices, ad platforms) paired with cross-functional knowledge (dbt, Terraform, SLI/SLO, AI workflows).
In the FFS (Five-Factors and Stress) personality assessment, my profile runs Diffusive → Preservative → Receptive: I start by generating ideas and acting on them, refine what works into systems that last, and give the results back to people and the organization. That sequence is the foundation of how I work.
Operationalization
Systems that keep running, not one-off fixes — replacing manual review with automation.
Redesigning operations
Observing and deconstructing workflows, then rebuilding them with the right mix of human judgment and AI.
From incident to strategy
Quantifying impact with SQL, building monitoring, and turning findings into investment decisions.
Regulated industries
Repeatedly shipping systems that respond directly to external regulation — from tax code changes to pharmaceutical ad compliance.
02
Skills
Backend
Frontend
Data / Analytics
Infra / Ops
AI / Other
03
Experience
Driving quality, reliability, and AI workflows across consumer web and pharmaceutical advertising products.
- Designed automated verification for medical guidance logic using Claude Code Skills and GitHub Actions
- Optimized video delivery (GCS + Fastly CDN) in four days, reducing transfer costs
- Analyzed issues in critical master data, quantified 23,000 lost opportunities, and proposed an external-data investment ROI model
- Implemented multi-tenant pharmaceutical ad distribution running simultaneous campaigns
Contributed to learning-data platform improvements and payment infrastructure.
- Helped drive learning-data platform improvements
- Implemented the Google Play In-App Billing backend infrastructure
- Reduced MongoDB costs through compression and schema optimization
Tax and consumption-tax compliance features, and event-driven microservices.
- Delivered tax-code and consumption-tax compliance features
- Maintained and operated event-driven microservices using Amazon SQS
Full-stack development across CMS, e-commerce, and chatbot systems.
- Built CMS platforms, e-commerce systems, and chatbot backends across the stack
04
Talks & Writing
Talks
- From ㍻ to U+32FF @ RubyKaigi 2019 LT Session
- Good to know yaml @ 平成Ruby会議01
- Google Play IAB(In-App Billing) 〜Railsでのサーバサイド対応のすべて〜 @ 銀座Rails #37
Writing
- 第3章 会計ソフトにおける改元対応 〜After RubyKaigi 2019〜 Money Forward Tech Book
- 第2章 Railsアプリケーションでの不要そうな定数・クラスの安全な剥がし方 Money Forward Techbook#2
05
Services
I take on the following kinds of freelance work. Early-stage inquiries — before requirements are fixed — are welcome too.
AI workflows & automation
Human-in-the-Loop workflow design with Claude / Claude Code. Replacing manual reviews and repetitive work with systems that keep running.
Data platforms & reliability (SLI/SLO)
Building and visualizing data platforms with BigQuery / dbt, and designing/operating SLI/SLOs — from incident quantification to monitoring.
Backend / Web app development (on request)
New builds, feature work, and refactoring are available on request — feel free to reach out so we can discuss the tech stack, content, and scope.
Technical advisory & ops improvement
Design consultation, code review, and dev-process setup, drawing on experience in regulated industries. Spot support for workflow redesign too.
Rate: from ¥8,000/hour (negotiable). I work mainly on weekends and weekday late nights (JST). Volume and workflow are open to discussion.
06
Contact
For work inquiries, feel free to reach out by email. A rough outline is enough to start.
Get in touch by emailI usually reply within 2–3 business days.