Senior Full-Stack Engineer
Autify, Inc. · Tokyo, Japan
April 2022 – Present
- Drove data analytics initiatives across the organization's Business Intelligence stack (cost tracking, data governance, incident reporting)
- Created an ETL pipeline (AWS Glue / Python) that processed 20M+ unstructured log records in days instead of weeks for AI self-healing analysis
- Built, as sole author, a fleet-wide dependency-update control plane: self-hosted Renovate as a GitHub App, deterministic rules first, then headless Claude Code grades each bot PR's risk and can auto-fix it on opt-in, with a human always merging; 55 of the repo's 59 merged PRs, grown to 16 managed repositories, replacing the vendor-hosted bot
- Sandboxed the pipeline's AI agents after finding that one write token could reach every managed repository: per-repo least-privilege App tokens, assess and fix in separate locked-down non-root containers, and the signing key behind a protected environment
- Built both products' MCP servers (web and mobile), turning every public API endpoint into an MCP tool; added agent scenario-authoring tools with write guards so an editor save can't silently overwrite an agent's change, and opened the mobile server to any API token behind a per-token rate limit (300 requests/min)
- Built an incident-response bot that posts context and answers on-call questions from 7 read-only MCP sources behind an MCP gateway on ECS Fargate, with read-only enforced by credentials rather than tool flags so a prompt injection can't write; piloted in live incidents, hardening its connections after each one
- Replaced an image-classification model with a deterministic DOM-based resolver, shadow-tested it behind a canary (3,505 decisions, 99.5% agreement where resolved), and recommended retiring the model, which was then removed
- Run my own engineering through a coding-agent loop: 213 of 313 PRs (Jun–Oct 2026) authored through Claude Code sessions in isolated worktrees, independent cross-harness self-review before posting, and 16 skills and 5 hooks I wrote that encode the team's PR process
- Maintained the test automation pipeline for web / mobile automation, serving 300+ companies
- Architected solutions for email delivery and PDF generation
- Debugged native Selenium WebDriver and Chromium internals to stabilize browser automation
- Active development on Chrome extensions for recording and replaying browser actions
- Reduced mobile device wait time by ~50% by pre-warming devices before test execution
- Assisted in building the test automation pipeline for a desktop application; drove development of the scheduling feature
- Deployed a self-serve infrastructure provisioning API (Pulumi) with AWS IAM permission isolation
- Prototyped a natural language AI Agent for mobile test automation (prompt adherence, element location, model selection)
- TypeScript
- React
- Redux
- Apollo GraphQL
- Electron
- Chrome Extension API
- Appium
- Ruby on Rails
- GraphQL
- Postgres
- SQLite
- Github Actions
- CircleCI
- Jest
- Testing Library
- Mock Service Worker
- RSpec
- Playwright
- AWS (ECS/EKS)
- Kubernetes
- Pulumi
- Terraform
- Holistics
- Athena
- Redshift
- Airbyte