Julien Marchand

VP of Engineering - Linea zkEVM @ Consensys

Paris, Île-de-France, France

About

I’m an engineering leader with 15+ years building and scaling software teams, and the last 8+ years have been spent at Consensys, where I’ve moved from tech lead to engineering manager to VP of Engineering for Linea zkEVM. At Consensys, I’ve led teams working on blockchain infrastructure and products that had to be both technically credible and actually usable: enterprise-grade protocols, key management, transaction orchestration, and now a Layer 2 ZK rollup built to bring Ethereum-grade security with materially lower transaction costs. That means shipping in environments where correctness, performance, security, and developer experience all matter at once. I like hard problems with real constraints: distributed systems, cryptography-adjacent infrastructure, protocol engineering, and the organizational side of making ambitious technical work land.

Experience

  • Consensys (Paris, Île-de-France, France)
    • VP of Engineering - Linea zkEVM @ Consensys
      Oct 2020 - Present · 5 yrs 9 mos

      I lead three teams covering backend and smart contract engineering, cryptography, and DevOps/security for Linea. The work spans protocol implementation, prover and arithmetization development, and the infrastructure and security foundations needed to run a zkEVM at scale.

    • Engineering Manager - Protocols @ Consensys
      Mar 2019 - Oct 2020 · 1 yr 8 mos

      Leading engineering teams focused on the development: Orchestrate & Quorum Key Manager: Plug & Play component that manages the full lifecycle of a transaction, from crafting to decoding. Orchestrate is meant to be used by Solutions Architects, Developers, Integrators, and others developing, deploying, and scaling enterprise blockchain solutions. Quorum Key Manager is a universal Key & Account Management solution for blockchain applications

    • Tech Lead & Architect
      Dec 2017 - Feb 2019 · 1 yr 3 mos

      Led prototyping and delivery of blockchain-native applications for enterprise clients, turning early-stage ideas into production-ready systems.

  • Tech Lead at EY Experience Lab at EY
    Sep 2015 - Dec 2017 · 2 yrs 4 mos

    As Tech Lead at the EY Experience Lab, I endorse the role of Data Scientist, full stack developer as well as project manager. ► Main missions - Lead projects involving scientific knowledge - Machine Learning, Deep Learning, Graph analysis - Conceive and implement an application development stack based on docker, Python/Flask and ReactJS mainly - Design of the data laboratory architecture - Manage development team and projects, external/internal communication - Trainer in Big Data / Python / coding best practices ► Main technologies - Machine Learning: scikit-learn, keras - Backend: Python Flask (flask-SQLAlchemy, flask-restful, flask-security, etc.) - Frontend: ReactJS (redux, react-router, redux-saga, etc.) - Big data: Hadoop, Spark, Hive - Other: Gitlab, docker

  • Data Scientist - Consultant at Bluestone (acquired by EY)
    Feb 2015 - Sep 2015 · 8 mos

    ►Consultant at L'Oréal: - Conception of a data extraction and processing software for client data - Query automation and optimization - Unsupervised Learning: development of a clustering tool (PCA, HAC & T-SNE) - Supervised Learning: development of a prediction module based on random forest and SVM - Dashboard of data visualisation / interactive clustering

  • Statistical analyst - Consultant at Keople
    Sep 2014 - Dec 2014 · 4 mos

    Data analysis and statistics to understand the digital knowledge of employees - banking sector

  • Intern developer at SAP
    Mar 2014 - Aug 2014 · 6 mos

    Storage, analysis and visualization of data from the LHC ➜ Development of an ETL into SAP HANA (In memory - column oriented DB) - C++ ➜ Development of a data analysis and visualization tool - JavaScript, OpenUI5 ➜ Data: subatomic particles from the Large Hadron Collider (CERN)