Ryota Ikezawa
Senior software engineer and architect with 10+ years of experience. At freee K.K. since November 2015, experiencing the company's growth from ~100 to 2,000+ employees. Progressed through data aggregation engineer, tech lead, EM, to current architect. Led legacy system remodeling, microservice design, and multi-tenant data isolation boundary design. Volunteered for an EM role for about a year, then returned to the TL/IC track to take responsibility for technology rather than people. Currently serving as architect on freee's HR/Payroll Integration Platform team. Continuous experience leading and delivering within globally distributed teams (Japan / Philippines). Core stack: Go, TypeScript, Ruby, Rails, React, Kubernetes, gRPC, MySQL, ArgoCD, Datadog.
Work Experience
10+ years at freee K.K. since November 2015, a cloud accounting software provider (100 → 2,000+ employees). Started with data aggregation feature development, progressed through Tech Lead and Engineering Manager roles, currently serving as Architect. Continuously involved in hiring and incident response. Leveraging tenure from early stage, contributed to multiple legacy system remodeling and re-architecture efforts.
Main focus: gRPC API redesign and re-delineation of application responsibility boundaries. Driving master data decomposition and microservice design in a multi-product environment where data and auth are tightly coupled with a large-scale monolith. Cross-team coordination with feature owners, auth platform, and QA teams. Also involved in ArgoCD GitOps deployment, cluster upgrade operations, and Datadog (APM / Logs / Infra) observability operations.
Built a Japan/Philippines hybrid team (4 engineers + 2 QA) from scratch as a playing manager, writing 40-50% of the code to deliver release in 6 months alongside planning. Later managed onboarding of mobile app team (2) and contract developers (4). Drove Schema-driven development using OpenAPI Generator, Orval, and TanStack Query.
As a contractor, handled Rails framework upgrades, dependency management, and migration from Paperclip to ActiveStorage.
Worked on infrastructure migration projects from on-premises environments to AWS (public cloud).
Projects
Access control middleware for Hono leveraging Cloudflare Workers request.cf properties.
Webhook signature verification middleware for Hono. Supports Stripe, GitHub, Slack, Shopify, Twilio and custom providers.
Idempotency middleware for Hono. Prevents duplicate request execution.
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Skills
Programming Languages
Frontend
Frameworks & Runtime
Databases
Infrastructure & Tooling