Julien Meyer (Lummix) Software Engineer

Performance.
By design.

Software Engineer at Diabolocom. I work on platform engineering, distributed systems and reliability for a large microservices-based contact center platform.

I care about performance: the kind you can measure, not the kind you claim.

Explore my work Let’s talk

Platform engineeringDistributed systemsReliability

Architecture. Precision. Execution.Explore

Engineering, testedin the real world.

93,000+

unique players on Nexiongames

people in the team I led

EPITA

Computer science graduate · 2025

01Selected work

Built in code.
Tested in the real world.

A private desktop app, multiplayer systems and gaming infrastructure. Three projects, the same attention to engineering.

CARNET / LOCAL DATAIN DEVELOPMENT

CarnetPrivacy, by design.

RustTauriReact

Read-only · Encrypted vault · No account

Local application & privacy01 / 03

Carnet

Your assets.
Your data, under your control.

A read-only desktop app for tracking crypto portfolios. Carnet reconstructs transaction history, cost basis and staking, with a Rust core and an encrypted local vault.

Rust
Tauri
React
TypeScript

Architecture and engineering challenges

Personal project · In development

Reconstructing transaction history from public identifiers and Coinbase / Coinbase Pro imports.
EUR valuations, weighted-average and FIFO cost basis, gain/loss and staking tracking.
An encrypted local vault using Argon2id and XChaCha20-Poly1305, with no account or application server.
Network access isolated in the Rust core; a React interface without network access and optional Tor support.

Discover Carnet

NOVA-X / UNREAL ENGINE 5WORK IN PROGRESS

NOVA

One world. Multiple systems.

C++gRPCJava

Multiplayer · Matchmaking · Backend

Real-time systems02 / 03

Nova-X

Connecting the game.
And everything behind it.

A tactical multiplayer FPS built with Unreal Engine 5. A personal project bringing together C++, matchmaking and Java backend services.

Unreal Engine 5
C++
Java
gRPC

Explore the project

Personal project in progress · Since July 2023

Developing a tactical FPS with multiple game modes.
Matchmaking and player statistics.
Built with C++, Java, gRPC, Docker and Kubernetes.

Discover Nova-X

NEXIONGAMES2016 — 2024

93,000+

unique players.

One infrastructure, one community.

Infrastructure & leadership03 / 03

Nexiongames

Building the systems.
Growing the team.

Developing Java game servers, optimizing infrastructure and leading a team of 20 people around a community of over 93,000 unique players.

Java / Spring
Linux
Docker
RabbitMQ

My role and the challenges

Software Developer & Team Lead · 2016–2024

Administering and optimizing Debian servers.
Designing a high-performance download server with Spring.
Developing Java game servers and coordinating the team.

Other explorations.

On GitHub

04In progress

Discover App

A mobile app for discovering local events, finding activities and planning group outings, with an interactive map and messaging.

Ionic / Vue · Java / Spring · PostgreSQL

05Academic project

Tiger Compiler

A compiler for the Tiger language, including parsing and an abstract syntax tree.

C++ · bison · flex

06Academic project

42sh

A Unix command-line interpreter implemented in C.

C · Unix

02Expertise

Every layer matters.

Distributed systems, observability and platform tooling. Measure how systems behave, then improve what matters.

Design.

Platforms & distributed systems

Designing and evolving shared backend services across a microservices platform, with scalability and resilience in mind.

Java
Spring
Microservices
Distributed systems

Measure.

Performance & observability

Strengthening observability and operational monitoring across services to understand behavior, guide optimization and improve reliability.

Observability
Telemetry
Performance
Resilience

Make it reliable.

Tooling & automation

Improving deployment automation, reliability across environments and shared engineering practices and tooling throughout the platform.

CI/CD
Automation
Docker
Kubernetes

Explore my full technical toolkit

Languages & frameworks

JavaSpring
RustTauri
C++Unreal Engine 5
TypeScript / JavaScriptReact · Vue · Node.js
C#.NET · Unity
PythonDjango
PHPLaravel

Tools & infrastructure

Git / GitLab
Linux
Docker / Kubernetes
MySQL / PostgreSQL
RabbitMQ
Redis
MongoDB
AWS
Elasticsearch
TeamCity

03Experience

Experience in the field.

Building, operating and coordinating. Experience shaped by real systems and the people behind them.

Currently2025 – Present
Software Engineer
Diabolocom
Platform engineering, distributed systems and reliability for a large microservices-based contact center platform.
- Improved overall platform performance, scalability and resilience.
- Strengthened observability and operational monitoring across services.
- Designed and evolved shared backend services for distributed systems.
- Improved deployment automation and reliability across environments.
- Standardized engineering practices and tooling across the platform.
Distributed systems · Microservices · Observability · CI/CD
2018 – 2024
Freelance Developer
Independent
Building tailored software for clients in finance and e-commerce.
- Developing REST APIs and integrating payment systems.
- Independent game development and technical consulting.
Java · REST APIs · Payments · Games
2016 – 2024
Nexiongames
Software Developer & Team Lead
Leading a team of 20 people and building the systems behind a community of over 93,000 unique players.
Java / Spring · Docker · RabbitMQ

04About

Driven
by curiosity.

An EPITA graduate, I enjoy understanding how things work, then making them work better. Distributed systems, platform engineering and performance are at the heart of my work. Outside of code, I find the same focus on precision and progress in sports and motorcycling.

Julien Meyer (Lummix)Software Engineer

Education

EPITASep 2020 – Jul 2025
MS in Computer Science · Graduated in 2025
Paris, France
Griffith CollegeJan 2021 – Jun 2021
Computer science exchange program
Cork, Ireland
Lycée épiscopal de ZillisheimSep 2017 – Jul 2019
French scientific baccalaureate
Zillisheim, France

Languages

FrenchNative
EnglishIntermediate
GermanIntermediate

05Let’s build what’s next

A technical challenge?
Let’s talk.

A project to build, a system to improve or a team to join. I’d be happy to discuss it with you.

[email protected]

LinkedIn GitHub

Julien Meyer (Lummix) / Software Engineer

Built in code.Tested in the real world.

Carnet

Nova-X

Nexiongames

Other explorations.

Discover App

Tiger Compiler

42sh

Every layer matters.

Design.

Measure.

Make it reliable.

Languages & frameworks

Tools & infrastructure

Experience in the field.

Software Engineer

Freelance Developer

Nexiongames

Drivenby curiosity.

Education

Languages

A technical challenge?Let’s talk.

Julien Meyer (Lummix) Software Engineer

Built in code.
Tested in the real world.

Driven
by curiosity.

A technical challenge?
Let’s talk.