I build backend systems, libraries, and developer tooling with a focus on clean API design, distributed systems, and performance.
Interested in JVM internals, PostgreSQL, asynchronous architectures, and open-source development.
Production-ready Kotlin Multiplatform implementation of RFC 9457 (Problem Details for HTTP APIs) with first-class support for Ktor and extensible integrations.
Tech: Kotlin Multiplatform · Ktor · kotlinx.serialization · RFC 9457 · Gradle
- Kotlin-first API for RFC 9457 Problem Details
- Multiplatform core (JVM / Android / Native / JS)
- Ktor integration for automatic exception handling
- Extensible architecture for custom serializers and frameworks
- Inspired by Spring's Problem Details support while remaining idiomatic for Kotlin
- Designing reusable Kotlin libraries
- Studying distributed systems and System Design
- Exploring PostgreSQL internals and performance
- Deepening knowledge of JVM and concurrency
Research project exploring PostgreSQL internals through reproducible experiments and benchmarks.
Tech: PostgreSQL · Java · Kotlin · Python · Docker · Gatling
- Storage engine experiments
- Query planner analysis
- Indexing research
- Benchmark visualization
Production-style search index management service built with Spring Boot and Kotlin.
Tech: Spring Boot · Kotlin · PostgreSQL · Kafka · MinIO · Docker Compose · Testcontainers
- Index versioning
- Kafka-based asynchronous processing
- S3-compatible storage
- Observability with Micrometer, Prometheus and Grafana
Hybrid Retrieval-Augmented Generation over a personal Zotero library.
Tech: Python · ChromaDB · BM25 · HyDE · FastMCP
- Hybrid semantic + keyword retrieval
- Parent-child chunking
- Incremental indexing
- MCP server for Claude Code
🇯🇵 Learning Japanese | 日本語を勉強しています