I'm Keitaro Kaneko
Full-stack Developer
As a freelance full-stack engineer, I handle everything from UI/UX design to frontend and backend implementation, maintenance, and operations. I have extensive project lead and PM experience, including customer negotiations and requirements organization, with hands-on experience across all phases from project launch to release. I have also led technical challenges such as tech lead roles for development teams and architecture overhauls from monolithic systems. My strengths lie not only in technical skills but also in business understanding and bridging with on-site teams, excelling in value delivery including problem discovery and improvement proposals.
Main Services
I provide end-to-end services including web system development, business improvement support, and project management. My strength is support with management and user perspectives, not just development.
UI/UX Design Support
From wireframe creation using Figma to information architecture (IA) and design system construction. With an engineer's perspective, I deliver highly usable UI designs that are easy to implement.
Project Management
Comprehensive support from requirements definition, progress management, task design to customer negotiations and proposal documentation. Practical experience with 10+ companies. Track record in competitive proposals and pre-sales.
Full-stack Development
Covering design through implementation, testing, and release in web app development centered on Rails and React. From greenfield development of management systems to maintenance and operations.
Maintenance & Improvement
Supporting resolution of on-site issues and optimization of operational systems including technical debt cleanup, eliminating knowledge silos, and improving investigation efficiency.
Tech Lead
Can lead complex technical challenges including technology selection, design policy formulation, monolith to modular monolith migration, and system architecture considering maintainability.
Team Management & Training
Managing development teams including new graduates, offshore, and contractors. Building team capabilities through 1-on-1s, evaluation systems, and training policy design.
Pricing Plans
I tailor proposals based on your specific needs and objectives. Below are typical support offerings and corresponding pricing plans. Initial consultation is free, so please feel free to reach out.
Growth
¥7,500
/hour
Professional
¥10,000
/hour
Strategic
¥13,000
/hour
Enterprise
¥18,000
/hour
* Hourly rates are pre-tax and can be negotiated based on content * Monthly fixed or contract agreements are also available
Work History
I started my career in market research and consulting, then progressed to business support utilizing web technology and business improvement system development. I have consistently aimed to be a partner who walks alongside customers in their challenges, engaging in business and development support. Currently, as a freelancer, I provide value across a wide range of areas, focusing on building business systems for SMEs and project promotion support.
Uzabase, Inc.etc.
Internship / Freelance
2017/1 ~ 2020/3
Consultant
- Handled internship in corporate analysis and accounting analysis at Uzabase (SPEEDA) for nearly 2 years
- Launched personal business Japavilion and started market research and consulting services
- Developed consulting in inbound/outbound areas including local customer research using FGI and interpretation/sales support for overseas exhibitions
TEMONA, Inc.
Employee
2020/4 ~ 2025/1
Project Manager
- Managed 10+ enterprise SaaS clients, providing end-to-end support from requirements definition to design and launch
- Contributed to building proposal-based customization frameworks for strategic clients, securing orders worth tens of millions of yen
- Led technical proposals in competitions through presales collaboration with sales, winning multiple projects
Full-stack Engineer
- Handled backend development with Rails/PostgreSQL and frontend development with React/Redux
- Provided comprehensive support for enterprise cart SaaS including SPA support, feature expansion, and maintenance
- Broadly covered AWS environment maintenance, database design, and API design
- Solved challenging technical issues like 4-company SSO integration with Auth0 and GA-compatible SSR architecture
- Led migration design and implementation for large-scale data migration project
- Received Development Division MVP award for contributions in both technical and business promotion
Tech Lead / Manager
- Led a development team of about 10 people (employees, contractors, offshore mix)
- Led modular monolith architecture adoption, fundamentally improving maintainability and extensibility of complex customization structures
- Achieved 0% team turnover through team restructuring, workflow improvements, and 1-on-1 care initiatives
Freelance
Freelance
2025/2 ~ Present
PM / Full-stack Engineer
- Started as an independent freelancer
- Rebranded Japavilion with services focused on B2B business improvement support, development support for system companies, and career support for individuals
- Led internal system development for insurance and rental car management—from problem identification through design and implementation from scratch. Promoted business digitalization and automation, contributing to paperless operations and cost reduction.
- Achieved DX promotion and information management efficiency through features like OneDrive integration and CSV auto-import
- Provided full-cycle support from requirements definition, UI design, backend/frontend development to AWS operations
- Secured ongoing projects through dedicated support including client negotiation, improvement proposals, and operational support
Skills
As a full-stack engineer, I can consistently lead the entire product lifecycle from design and implementation to maintenance and operations. Beyond frontend, backend, and infrastructure/DevOps, I've expanded my expertise to include architecture design, team management, and business efficiency scripting. I strive to enhance my technical skills through both practical experience and systematic learning.
* Skill proficiency is quantitatively organized based on my achievements, using a TOEIC score of 860 as a benchmark for 86% proficiency.
Figma
Bootstrap Studio
Adobe XD
PhotoshopRequirements Organization
92%
Led issue extraction to specification definition through business hearings with enterprise clients. Excel at translating abstract needs into concrete requirements.
Information Architecture
80%
Wide-ranging experience from LP creation to internal management system screen composition design. Conducted wireframe and IA design across multiple projects with extensive experience in creating materials for non-engineers.
UI Design
85%
Experience in component design and design system construction with Figma. Skilled in UI design emphasizing reusability and maintainability, compatible with Next.js + Tailwind CSS architecture.
System Design
78%
Handled product-wide screen transition design and user flow design. Implemented flexible system design considering operation phase alongside Figma component design.
UX Improvement
70%
Identified issues through usability testing and on-site hearings, contributing to UI improvement and business workflow optimization. Practiced PDCA cycles based on data collection and hypothesis verification.
Story Mapping
68%
Conducted feature organization and prioritization based on user stories in requirements definition phase. Can handle customer journey design and product backlog organization.
Persona Design
58%
Handled target user analysis to persona and tone & manner design for corporate and service sites. Contributed to requirements organization incorporating marketing perspectives.