Full-stack & data engineer

Nikolas
Contessotto

I design and run the data and product chain end to end:
pipelines, platforms, and the measurement that proves they work.
Currently CEO of Yūgen K.K. in Tokyo.

  • 3+years engineering
  • 9years shipping work
  • 3languages spoken
  • 1company founded

Activity / github

Still shipping.

lessmore

5,770 contributions since 2024 · 2,021 in private repos · 126 repositories · peak 84 on 15 Aug 2024

2026

2,128 contributions137 active days

2025

2,858 contributions221 active days

2024

784 contributions38 active days

Career / 2013 to 2026

Two careers, plotted.

  • Engineering: Nikodev, 2023 to 2026
  • Engineering: Yūgen K.K., 2026 to present
  • Business: Yūgen K.K., 2026 to present
  • Education: Brassart School, 2013 to 2016
  • Education: Bellecour School, 2016 to 2018
  • Education: ISI, 2024 to 2024
  • Education: Le Wagon, 2024 to 2024
  • Education: Le Wagon, 2026 to 2026
  • Design & film: Multi-Motion, 2013 to 2017
  • Design & film: Zar, 2017 to 2018
  • Design & film: SwissBorg, 2019 to 2020
  • Design & film: Cardemy, 2020 to 2021

Scroll the chart sideways →

Path / in detail

Where the years went.

Apr 2026 → Present

  • business
  • engineering

CEO · Yūgen K.K.

Tokyo, Japan · Hybrid · CDI

The studio that helps craftsmanship travel.
B2B development and ambassadorship for foreign brands in Japan.
I build the platforms and the data layer behind it, not just run it.

  • Founded a studio that carries French and Japanese products into each other's markets, covering all eight links of the chain from market study to logistics and tracking, by keeping every discipline in house rather than brokering it out.
  • Give an existing concept or product a second life abroad without asking the producer to change how they work, by handling market studies, storytelling, packaging, film, commerce and distribution on their behalf.
  • Own the studio's entire technical layer, from the commerce platforms to the internal tooling and the dashboards the business is measured on, by designing, building and deploying them personally rather than outsourcing them.
  • Keep engineering as a daily practice while running the company, by treating the studio's own stack as a product with the same standards as client work.
  • B2B
  • Business development
  • E-commerce
  • TypeScript
  • Next.js
  • MongoDB
  • Analytics
  • Branding
  • Logistics

Mar 2023 → May 2026

  • engineering

Full-stack Developer · Nikodev

Tokyo, Japan · Hybrid · Freelance

Custom B2B digital tools for clients.
Workflow automation, data pipelines, and the operations they support.

  • Delivered custom B2B tooling to clients across 3 years and 2 months of continuous freelance work, by automating their business workflows and structuring the data pipelines underneath.
  • Shipped scalable web applications end to end, from architecture design through frontend, backend and deployment, by working as the sole engineer on each engagement.
  • Prepared developers for professional roles through mentoring and tutoring, by teaching practical software engineering rather than textbook exercises.
  • TypeScript
  • React
  • Next.js
  • Node.js
  • Python
  • Data pipelines
  • Architecture
  • Workflow automation
  • Mentoring

Jul 2020 → Feb 2021

  • design

Video Editor · Cardemy

Évian-les-Bains, France · Remote · Freelance

Moderation and editing of Japanese YouTube videos used as learning support.

  • Turned raw Japanese YouTube content into structured learning support over an 8 month engagement, by analysing each source video first and cutting it to the teaching point.
  • Video production
  • Adobe Suite

Sep 2019 → Jul 2020

  • design

Video Producer · SwissBorg

Switzerland · Hybrid · CDD

Hired as an intern.
Left as the employee responsible for video production.

  • Went from intern to the employee responsible for video in 11 months, by taking on pre-scripting, storyboarding, camera work, editing and visual effects end to end.
  • Contributed to the B2C communication strategy for the conversion funnel, producing the templates, videos and visual aids it ran on, by pairing customer interviews with marketing design.
  • Video production
  • Adobe Suite
  • Photography
  • Branding

May 2017 → Aug 2018

  • design

Video-Maker Manager · Zar

Lyon, France · Remote · CDD

Led a team of four graphic designers.
Produced a Masterclass for players' professional development.

  • Led 4 graphic designers to deliver a full professional-development Masterclass, by owning the scripts, the Premiere Pro and After Effects pipeline, and the team's schedule.
  • Kept a 16 month production on track, by planning the team's work week to week and mentoring designers through the parts they had not done before.
  • Team management
  • Video production
  • Adobe Suite
  • Mentoring

Mar 2013 → Jan 2017

  • design

Freelance 2D/3D Designer & Video Editor · Multi-Motion

Annecy, France · On-site · Freelance

Client work in 3D, video, audio and print.
It funded my studies along the way.

  • Delivered 3D models, video, audio, logos and print to client brief across 4 years of freelance work, by running several projects in parallel and holding every deadline.
  • Funded my own education from the income, by treating the freelance practice as a business rather than a side job.
  • 2D/3D
  • Video production
  • Adobe Suite

Education

  • Jun 2026 → Sep 2026 (expected)in progress

    Data Science & Machine Learning Bootcamp

    Le Wagon

  • Jun 2024 → Sep 2024

    Full-Stack Developer Training

    Le Wagon

  • Jan 2024 → Jun 2024

    Japanese Language Program

    ISI, International Study Institute Tokyo

  • Sep 2016 → Sep 2018

    Bachelor, Character & Environment Design

    Bellecour School

  • Sep 2013 → Sep 2016

    Bachelor, 3D / VFX

    Brassart School

Stack / distribution

What I actually write.

  • TypeScript40%
  • Python40%
  • Ruby5%
  • Go4%
  • Other11%

Share of code across 14 public repositories, measured via the GitHub API. Notebooks counted as Python.

  • Frontend

    • React
    • Next.js
    • TypeScript
    • Vite
    • Tailwind
  • Backend

    • Go / Gin
    • Express
    • FastAPI
    • Rails
    • MongoDB
  • Data

    • Python
    • Pandas
    • BigQuery
    • Jupyter
    • ETL pipelines
  • Design

    • Figma
    • Adobe Suite
    • 3D / VFX
    • Film & motion
    • Brand systems

Work / shipped

Selected projects.

  • GGStats

    github.com/NikoMastro/GGStats

    Data science / engineering

    League of Legends analytics over 80,644 ranked games pulled from the Riot API.
    The pipeline explains its own statistical choices rather than hiding them.

    Python · FastAPI · React · Docker

    2026

  • PageForge

    github.com/NikoMastro/pageforge

    Software engineering

    Visual landing page and link-in-bio builder producing versioned JSON pages.
    Built as a production platform; the public repo is a sanitized showcase.

    TypeScript · React/Vite · Express · MongoDB

    live demo ↗

    2024

    Showcase repo published 2026

  • Pulse

    github.com/NikoMastro/IntAppShowcase

    Software engineering

    SDK analytics console for a multi-tenant production platform.
    The live demo runs on synthetic data; the public repo is a sanitized showcase.

    Go/Gin · React/Vite · MongoDB · BigQuery

    live demo ↗

    2025

    Showcase repo published 2026