JUN KIMURA

I’m a hacker and entrepreneur. I have been generalizing complex problems and developing various frameworks and middleware to solve them. I can not only develop cutting edge technologies, but also use these technologies to develop products that solve real world problems.

Professional experience

Datachain(2018-): Co-founder, CTO, Blockchain engineer

  • Lead research and development in blockchain interoperability
  • Design and development in PoC with partner companies
  • See the project details “Media” section.

The following is a representative list of projects:

  • Hyperledger YUI: DLT/Blockchain interoperability framework (Especially, I developed Ethereum, Fabric, and IBC Relayer)
  • Cross Framework: A framework empowers the development of smart contracts that support cross-chain transactions.
  • Hypermint: Blockchain supports WASM-based smart contract
  • Plasma chain(Ethereum L2 scaling solution): Solidity, Golang, Tendermint

Freelance

Developed backend systems in adtech domain. Mainly designed and developed the backend of systems that can handle high traffic.

  • A high-traffic ad server(over 100,000rps): Golang, Aerospike, AWS, Jenkins, Ansible, etc.
  • Developed a batch system that transfers large ad tracking logs: Golang, Fluentd, go-flow

Momentum(2014-2017): Co-founder, CTO

Developed the Ad verification service to protect advertisers from reputation risks when serving ads, and introduced it to DSP and Ad networks.

  • Ad verfication service(Brand safety, Ad fraud protection): Go, JavaScript, Python, AWS, GCP(BigQuery)
  • Developed a batch system that enables crawling tens of millions of URLs per hour.
  • Implemented a classifier for categorizing web pages in cooperation with a laboratory at Tokyo Institute of Technology.
  • Acquired by KDDI group company

JustSystems(2013): Software engineer

  • Researched and developed an application of similar image retrieval as an experimental project for new graduates: Python, OpenCV, Apache Solr
  • Developed a backend system for social commerce service: Java, Scala, Play Framework, PostgreSQL, Redis, AWS, etc.

OSS (Only as founder)

The following lists are only as founder. Other contributions can be checked in my github account: https://github.com/bluele

Miscellaneous

Technology

  • Programming Languages: Go, Rust, C, Python, JavaScript
  • Database: MySQL, Redis, Aerospike
  • DLT/Blockchain: Hyperledger Fabric, Ethereum, Tendermint, Cosmos-SDK, IBC
  • Public cloud: mostly AWS, sometimes GCP
  • Others: Implemetations of DLT/Blockchain, Consensus engine, distributed algorithms

Media