You're seeing this page as if you were . The main menu is still yours, though. Exit from immersion
Corentin BilloCB

Corentin Billo

Software Engineer – Financial Services

€500/day
Paris, FR
3-7 years

Average response time: 1 hour

About Corentin

Je m’appelle Corentin, issu d’une grande école d’ingénieur française, j’ai plusieurs années d’expérience dans le secteur de l’IT, que cela soit en conseil stratégique pour la région IdF ou du technique dans les applications crédit de la SG. J’ai également créé plusieurs applications sur mon temps libre (SaaS d’analyse complète d’applications sur le mainframe, Saas d’intermédiation pour améliorer son contexte via de la gen MCP personnalisée à partir du parsing et analyse complète de repo Git et d’autres applications mobiles)

Je maitrise plusieurs langages de programmation et propose des services de cleaning et amélioration de contexte à destination des solopreneurs vibe codeurs. Je reprends vos projets en cours et instaure toutes les bonnes pratiques pour booster les résultats de vos agents sur votre produit. Donnez d’avantage vie à vos idées sans devoir repasser sur vos features à cause de soucis contextuels.
  • French

    Native or bilingual

  • English

    Fluent

  • Spanish

    Conversational

  • German

    Conversational

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

Experience

  • Covalyo (covalyo.com)
    Founder – AI-powered B2B SaaS Platform
    January 2025 - Today (1 year and 6 months)
    • • Took an AI product from concept to shipped, external-facing platform solo: LLMs that extract, document, and translate business logic from legacy COBOL systems for banks and insurers
    • • Designed and tuned the agent loops and prompt pipelines, then built an evaluation harness that pushed output quality to 95/100 on complex financial code – correctness and reproducibility as a first-class concern
    • • Built the full stack and operate it end-to-end: frontend, backend services, hosting (Vercel, Railway, AWS), database (Neon/PostgreSQL), CI/CD (GitHub)
    • • Engineered a multi-agent development workflow (Claude Code): role-specialized sub-agents, custom slash commands, hook based guardrails protecting critical files, and token-usage optimization
    Stack: Python, LLM APIs (Claude, GPT), agent frameworks, prompt engineering, evals, Vercel, AWS, Docker, GitHub
    Vibe coding Mainframe COBOL JCL Parsing
  • Storizzz
    Co-founder – AI-powered Mobile Application
    December 2023 - August 2025 (1 year and 8 months)
    France
    • • Co-built and shipped a consumer app generating personalized content with LLM/NLP, iterating on real user feedback
    • • Architected the agent/API integration layer connecting a Fluter frontend to multiple LLM providers in
    Meta Ads Recrutement Instagram Marketing Flutter ChatGPT
  • Sopra Steria (Société Générale)
    Software Engineer – Financial Services
    February 2026 - Today (5 months)
    Lille, France
    • • Build and maintain mission-critical banking applications where reliability and correctness are non-negotiable
    • • Diagnose and resolve complex production incidents on transactional flows; translate business logic into specs
    • • Ship into a high-availability production environment alongside business and technical teams in Agile
    Stack: Java, SQL, COBOL, DB2, JCL, CICS, production reliability
    COBOL Secteur bancaire Crédit JCL Process Mapping

Recommendations

Be the first to recommend Corentin

Help this freelancer shine by sharing your experience working together.

These freelancer profiles also match your criteria

AgathaA

Agatha Frydrych

Backend Java Software Engineer

4.7

(3)

2

BaptisteB

Baptiste Duhen

Fullstack developer

4.6

(4)

5

AmedA

Amed Hamou

Senior Lead Developer

4

(2)

7

AudreyA

Audrey Champion

Web developer

4.3

(3)

4

Education

  • Azure AI Fundamentals (AI-900)
    Microsoft
    2026
    Azure AI Fundamentals (AI-900)
  • Mainframe & Java/JEE Intensive Program
    ACTIV' CONSULT' TRAINING
    2026
    Mainframe & Java/JEE Intensive Program

Categories