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Ryota Ikezawa

Ryota Ikezawa

Senior Software Engineer / Architect

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 SWE roles — data aggregation development, tech lead, EM, architect — before moving to SRE. 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. After serving as architect on freee's HR/Payroll Integration Platform team, moved to SRE in June 2026 as tech lead on platform engineering. 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

freee K.K. 10 years
2015/11 - Present

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, Engineering Manager, and Architect roles, currently serving as SRE Tech Lead. Continuously involved in hiring and incident response. Leveraging tenure from early stage, contributed to multiple existing-system remodeling and re-architecture efforts.

Current
Site Reliability Engineer / Tech Lead
Platform Engineering
2026/06 - Present

Tech lead on the SRE team, driving platform engineering. Focused on observability and self-service-driven developer experience across the platform, including the container infrastructure and networking.

Kubernetes
Istio
ArgoCD
KEDA
Fluentd
+2
Senior Software Engineer / Architect
HR/Payroll Integration Platform
2025/01 - 2026/05

Led the team as EM during the launch phase (first ~6 months), then moved to the Architect/IC track. Main focus: gRPC API redesign and re-delineation of application responsibility boundaries. Drove master data decomposition and microservice design across a multi-product environment. Cross-team coordination with feature owners, auth platform, and QA teams.

Go
Ruby
Rails
TypeScript
React
+6
ACALL Inc. Less than 1 year
2018/08 - 2019/04

As a contractor, handled Rails framework upgrades, dependency management, and migration from Paperclip to ActiveStorage.

Ruby
Rails
ActiveStorage
Exetop Technology Inc. Less than 1 year
2015/04 - 2015/10

Worked on infrastructure migration projects from on-premises environments to AWS (public cloud).

AWS
Linux
On-premises Migration

Projects

hono-problem-details
OSS

RFC 9457 Problem Details middleware for Hono.

Hono
TypeScript
hono-cf-access
OSS

Access control middleware for Hono leveraging Cloudflare Workers request.cf properties.

Hono
TypeScript
Cloudflare Workers
hono-webhook-verify
OSS

Webhook signature verification middleware for Hono. Supports Stripe, GitHub, Slack, Shopify, Twilio and custom providers.

Hono
TypeScript
hono-idempotency
OSS

Idempotency middleware for Hono. Prevents duplicate request execution.

Hono
TypeScript
Tuck
Personal

Read it later app. Efficiently search and organize saved content with AI-powered semantic search and vector search.

React
TypeScript
Hono
Cloudflare Workers
Drizzle ORM
+1
funailog
Personal

Personal tech blog. Built with Astro and deployed to Cloudflare Workers.

Astro
React
TypeScript
Tailwind CSS
Cloudflare Workers

Skills

Programming Languages

Go
TypeScript
Ruby
Python

Frontend

React
Next.js
Astro

Frameworks & Runtime

Ruby on Rails
Hono
Node.js

Databases

MySQL
PostgreSQL

Infrastructure & Tooling

Kubernetes
Docker
ArgoCD
Datadog
gRPC
Istio
KEDA
Fluentd
AWS
Cloudflare Workers

Education

Senshu University
Bachelor of Law Political Science 2011/04 - 2015/03