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Léo MerranLM

Léo Merran

Fullstack Java/Typescript Developer | Ex-Theodo

€560/day
Paris, FR
3-7 years

Average response time: 1 hour

Freelancer profile translated to English.
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About Léo

6 years of experience in fullstack development, including 4 years atTheodowhere I delivered complex projects for major clients and scale-ups.

Tech Lead for the last 3 years, I managed teams of 3 to 6 developers while staying hands-on. My main stack: **Spring Boot, Angular, NestJS, TypeScript**.

What I bring: the ability to technically frame a project, deliver quickly, and upskill the teams around me. Strong product appetite - I design features end-to-end, from user needs to deployment.
  • French

    Native or bilingual

  • English

    Fluent

  • Spanish

    Basic

Can work on-site
Paris (up to 50km)

Experience

  • Riot Security
    Senior Software Engineer
    EDUCATION AND E-LEARNING
    February 2026 - Today (4 months)
    Paris, France
    • • Stack: Elixir, Phoenix, Ecto, Metabase, Sentry, Datadog
    • • Development of a Bot to push cybersecurity courses to employees during their free time
    • • Integrations with internal company communication tools: Slack, Teams, and Google Chat
    • • Use of Claude Code to parallelize tasks
    Elixir Sentry Ecto Phoenix Cybersecurity
  • Theodo Fintech
    Tech Lead
    BANKING AND INSURANCE
    April 2023 - January 2026 (2 years and 9 months)
    Paris, France
    • • Stack: Angular, Spring Boot, Kotlin, Nest.js, React Native, Kafka, Sentry, Amplitude, Matomo, Metabase, Elastic Search, Datadog
    • • Management of teams of 2 to 4 developers (including freelancers) on BPI and LCL projects
    Code review, risk anticipation, developer upskilling (competency matrices, training)
    Design and implementation of a microservice in hexagonal architecture based on Kafka within an ecosystem of 6 frontends and 23 APIs
    Development of a back-office for account managers, management of inter-team dependencies
    Takeover and modernization of a CMS platform with a white-label solution and performance optimization
    Creation of the banking onboarding journey (Lpro by LCL) - banking security, regulatory compliance
    Direct contact with regional administrations, participation in promotional events
    Application of the Lean method (value prioritization, continuous improvement, stop at defect)
    Spring boot Angular NestJs DevOps Legislation
  • Theodo Fintech
    Software Engineer
    BANKING AND INSURANCE
    February 2022 - April 2023 (1 year and 2 months)
    Paris, France
    • • Stack: Angular, Spring Boot, Sentry, Metabase, Elastic Search
    • • Development on the BPI – BEL CDA project
    • • Angular Referent for ~150 developers (training, pair programming, code review)
    • • Implementation of Sentry and internal/external technical presentation
    • • Automation of production flows for 15 teams via Notion (bug management, reporting, Pareto)
    Angular Spring boot Sentry Metabase Hexagonal Architecture

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Education

  • Master 2
    EFREI Paris
    2020
    Master 2
  • Licence 3
    APU
    2018
    Licence 3

Skill set

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