# Kazusa Tsubota

Kazusa Tsubota is a remote worker on Himalayas, Mobile / Web Engineer at Madoromi, Inc, based in Japan.

Source: https://himalayas.app/@kazusatsubota1

```text
Full-stack AI engineer building products with Next.js, Python, and LLM agents. Skilled in RAG, AWS, and production monitoring.
```

| Detail | Value |
| --- | --- |
| Availability | Looking for a job |
| Location | Japan |
| Authorized to work in | Japan, United States, United Kingdom |
| Salary expectations | 60k+ USD |
| Job categories | Full Stack AI Engineer, AI Engineer, Backend Engineer, Mobile Engineer, Infrastructure Engineer |
| Skills | Fullstack Development, AI Engineering, LLM Integrations, RAG, Tool calling, Backend Engineering, Cloud Infrastructure, Frontend Architecture, Backend For Frontend (BFF), REST APIs |
| LinkedIn | https://linkedin.com/in/kazusa-tsubota-241485358 |

## About

```text
I'm a full-stack engineer with 7+ years of experience building products across retail SaaS, Web3, and AI. At ScalyX.ai, I develop a retail management platform with Next.js, Python/FastAPI, and PostgreSQL, and build AI agents that combine RAG, semantic search, and tool calling to help users find information and complete workflows. I also work with LangChain, LangGraph, A2UI, and Whisper to create interactive and voice-enabled agent experiences.

My experience spans frontend architecture, BFF and API design, cloud infrastructure, and production observability. At AllWeb3, I led the technical direction of a Next.js and React frontend, shaping its architecture, project structure, and reusable component system. I have operated services on AWS and Kubernetes, including a migration for a platform serving 30+ tenants that reduced average monthly infrastructure costs by approximately 17%. I also build cross-platform mobile apps with React Native and Expo. I enjoy owning product features end to end and working closely with product and design teams.
```

## Experience

### Mobile / Web Engineer (current)

Madoromi, Inc. Aug 2026 - Present

```text
Developed a cross-platform iOS and Android application with React Native and Expo, including onboarding and API integration. Built the user-facing website with Next.js, including authentication and subscription checkout.
```

Skills: React-Native, Expo, Next.js, Clerk, Stripe, Deep-Links

### Full-Stack / AI Application Engineer (current)

ScalyX.ai. Jan 2024 - Present

```text
Built retail management features using Next.js, Python/FastAPI, and PostgreSQL. Developed RAG agents with LangChain/LangGraph, semantic search, and tool calling; added A2UI responses and Whisper speech-to-text. Set up Prometheus, Grafana, OpenTelemetry, Jaeger, and CloudWatch, cutting investigation time 40%. Migrated 30+ tenants to shared AWS EKS, reducing monthly infrastructure costs ~17%.
```

### Infrastructure / Full-Stack Engineer

AllWeb3. Jan 2022 - Oct 2023

```text
Led technical direction for a Web3 marketing platform, designing frontend architecture and a BFF layer. Consolidated backend services into a NestJS monorepo, reducing infrastructure costs.
```

Skills: Next.js, React, TypeScript, NestJS, PostgreSQL, BFF, TurboRepo, AWS-Lambda, EventBridge, OpenAPI

### Full-Stack Engineer

StoreHub. Dec 2018 - Dec 2021

```text
Developed inventory management features for a cloud POS and retail SaaS platform, building React and Next.js interfaces and Node.js REST APIs. Implemented employee management features and inventory import tools.
```

Skills: React, Next.js, NodeJS, REST-APIs, PostgreSQL, CSV, Excel, SQL

## Education

### University of Malaya

Bachelor of Engineering, Computer and Intelligent Systems Engineering

```text
Bachelor of Engineering in Computer and Intelligent Systems Engineering from the University of Malaya, completed in 2018.
```

## Tech stack

- OpenAPI
- Amazon CloudWatch
- Kubernetes
- Amazon EKS
- React Native
- Expo
- PostgreSQL
- Node.js
- Next.js
- NestJS
- Tailwind CSS
- Terraform
- React
- Python
- FastAPI
- Grafana
- Prometheus
- OpenTelemetry
- Stripe
- AWS Lambda
- TypeScript
- Docker
- Jaeger
- Amazon EventBridge
- LangChain
- Turborepo
- vLLM
- Clerk
- pgvector
- LangGraph
- Retrieval-Augmented Generation (RAG)
- AWS
- REST APIs

To contact Kazusa, message them from this profile with a Himalayas employer account: [Hire on Himalayas](https://himalayas.app/hire).

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