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David Hagege

CTO & Staff-level Software Engineer

Remote (Japan, JST). Open to US/EU/Oceania overlap

About

CTO & Staff-level Software Engineer with 18+ years building scalable systems. Available for both full-time employment and contract engagements. Passionate about reducing complexity, automating painful workflows, and enabling async-first teams. Experienced in MLOps and production ML integration. Believer in open-source, hardware/software hacking, and building tools that outlive their use cases.

Work Experience

Listenfield Inc.

2021-03-01 — 2026-06-30 (5 years 5 months)

CTO & Staff-level Software Engineer https://www.listenfield.com/

Agritech: Transformed a struggling ~40 person, ~12 nationality startup into an AgriTech leader in SEA. Building production AI systems serving 40,000+ users with satellite imagery, weather forecasting, and IoT solutions for crop health and yield estimation.

  • Led the redevelopment of a 4 years old mobile & web app with 40,000+ users in 5 months.
  • Built a forecasting weather API using SQL-based interpolation on hundreds of millions of rows, delivering 2-year global weather predictions at any coordinate
  • Developed a production RAG pipeline enabling farmers to mass create farming activities via natural language prompts instead of forms, completely eliminating form fatigue.
  • Developed an IoT platform for tractors that drastically reduced billing and management errors
  • Shifted org to async-first workflows via GitLab use. Reduced meeting load from daily to ~1/week, freeing 10+ hours/week for deep work.
  • Established Nix/NixOS as the standard for dev environments and deployments, cutting onboarding from days to minutes and fixing dependency hell.
  • In month one, consolidated repos by 90% and refactored infra away from microservices, reducing operational complexity drastically.
  • Built a scalable pipeline using PubSub & cloud functions for satellite image fetching (100,000+ images/day) and worked closely with researchers to integrate their ML models in production
  • Conducted 4+ hours of daily code reviews across the team, improving code quality and upskilling all engineers
  • Built an employee handbook in Hugo that became the primary onboarding resource and company-wide documentation hub

Joynetiks

2020-07-01 — Present (6 years 3 months +)

Extraordinary Software Development Services

  • Joynetiks provides top-notch software development and consulting services to companies of all sizes, with a focus on bringing Joy to everyone involved.

Zeppelin

2020-07-01 — 2020-12-01 (5 months)

Lead Engineer (Freelance work) https://www.zeppelin.co.jp/

AR mobile apps / shopping platform

  • Implemented robust development processes, including CI and testing, to improve efficiency and code quality on a previously disorganized project.
  • Initiated the migration from Firestore to SQL on GCP (contributing to firebase in the meantime), successfully designed and built the entire backend for the app.
  • Guided and mentored other engineers in making informed decisions and delivering high-quality work.

Persol Career / BRS

2019-05-01 — 2020-06-30 (1 year 2 months)

Japanese HR company that operates Doda.jp. As the tech lead of their HR Tech team, I was responsible for modernizing their systems.

  • Developed a chrome extension that significantly improved the efficiency of recruiters and saved the company millions of yen.
  • Identified and remedied multiple security vulnerabilities in the company's servers and processes.
  • Set up and supervised Kubernetes clusters with Terraform on GCP to provide easy deployment of all their services. Implemented SSO to protect their services.
  • Created a new website from scratch using React and Rails with Elasticsearch integration, providing a faster and more effective search experience that was fully synchronized with the company's Salesforce system.
  • Made all technical decisions and adhered to strict compliance regulations.
  • Introduced automatic testing for the engineering hiring process, resulting in a 80% reduction in the number of applicants and saving hours of interview time.

En-Japan

2014-12-01 — 2019-05-01 (4 years 6 months)

Software Engineer

A famous Japanese HR company. Scala and ruby on rails development.

  • Worked on Vibe.work, a tool to analyze your team's morale with machine learning.
  • Developed a highly popular team building platform (https://ludo.team), which continues to have over a thousand active users per month and has attracted clients such as Electronic Arts and BestBuy.
  • Implemented an RPA solution that saved the company nearly 1 million USD annually.
  • Mentored coworkers in Ruby on Rails and provided programming instruction to non-technical team members.
  • Created enscalator, an open source tool for generating AWS CloudFormation templates, saving hundreds of hours of DevOps work within the team.
  • Developed web crawlers to efficiently crawl and index hundred thousands of job postings from across the web.

Orange labs Tokyo/Seoul

2012-06-01 — 2014-12-01 (2 years 6 months)

Research Engineer

Orange, the third largest telecom company in Europe. I had the opportunity to work in their labs in Tokyo and Seoul for a total of two and a half years.

  • Developed Android apps with a Scala frontend and Ruby backend.
  • Utilized a Kinect sensor to track consumer behavior and gather data on in-store customers.
  • Designed a hot desk system using phones, wireless charging, and Miracast technology years before Samsung DEX, hacking my own Android ROM for seamless integration
  • Worked on a solution for remotely controlling Android phones for technical support purposes.

Myndpage

2011-02-01 — 2012-02-01 (1 year)

Founder

Myndpage is a unique social network of brains that allows users to connect based on shared thoughts and ideas, using tags to identify like-minded individuals.

  • Achieved to get Angel investor funding from France & Dubai

LaCie (Seagate)

2008-01-01 — 2010-04-01 (2 years 3 months)

Software Engineer http://lacie.com

Now owned by Seagate. Storage solutions, hard drives, NAS and accessories.

  • Performed cross-platform development in C and C++ for Network Attached Storage (NAS) and Direct Attached Storage (DAS) systems on Linux, OSX, and Windows.
  • Created a multi-user interface for managing LaCie's encrypted DAS devices with biometric recognition.
  • Ported a NAS management software to Linux.
  • Conducted a complete rewrite of a tool for formatting hard drives in various scenarios, including the introduction of a new capsule file system with LaCie manuals and tools.

Novo Nordisk Laboratories

2008-01-01 — 2008-03-01 (2 months)

Software Engineer (contract)

Famous Pharmaceutical company. Cross-platform development in Python 2.4 of a child growth hormone prescription application used by physicians.

Personal Projects

I have many personal projects that are too numerous to list here, but you can view some highlights by clicking below:

Skills

Frontend

NextJS React Mobx-state-tree Typescript Tailwind TanStack Svelte Firebase d3.js Responsiveness

Backend

Ruby on Rails Postgresql PostGIS PGVector GEE Python Elasticsearch Express ActionCable OpenAPI Sequelize Memcache Sidekiq Fastify RSpec MQTT Scala Redis NoSQL RabbitMQ C C++ PHP

AI/ML

RAG MCP Tools RubyLLM Optuna LiteLLM Ralph Loops Eval harnesses llama.cpp LakeFS MLOps

CV

YOLO Albumentations Roboflow

DevOps

Linux (NixOS, Gentoo, Arch, 25 years exp) CI/CD GCP AWS PubSub CloudRun Kubernetes Terraform Serverless NewRelic Grafana Rollbar Traefik Gitlab Helm Caddy Docker Plan9

Hardware

PCB design CAD Arduino ESP32 ASM 3D Printing

Mobile

Android SDK NDK

Security

PE infector in asm x86 Buffer overflow exploitation ROP gadgets (ASLR bypass) SQL injection XSS/CSRF

Languages

French

Native speaker

English

TOEIC 910

Japanese

ILR Level 2

Korean

ILR Level 1

Spanish

ILR Level 1

Interests

Hydroponics and self-sufficiency Electrical engineering, Hardware reverse engineering, PCB design, 3D printing, CAD, building keyboards Cryptography, Open Source and the Cypherpunk movement

Education

Epitech - European institute of Technology

Master of Engineering

2006 - 2011