11/05/2026 updated

DD
100 % available

Freelance CTO | Founding Engineer | Hands-on Architect | Generative AI & Distributed Systems

France
Only remote
DUT in Computer Science, Digital Imaging option - Arles, France, 2005
France
Only remote
DUT in Computer Science, Digital Imaging option - Arles, France, 2005

Profile attachments

David_Djian_CV_English.pdf

About me

Freelance CTO and hands-on architect with 20 years of experience building high-traffic products, distributed real-time systems and production AI platforms. I work from architecture to delivery across TypeScript/Node.js, Python, React/Next.js, AWS and GCP.

Software ArchitectureNext.jsGenerative AILive Streaming
Software Architecture
Expertise in DDD, CQRS, Clean Architecture, Microservices, Event-driven design, REST, GraphQL and WebSockets. Design of scalable full-stack architectures and multi-region cloud deployments for high-traffic platforms.

AI and Data Systems
Deep knowledge of LLMs, OpenAI, Mistral and Gemini, RAG, vector databases, AI agents and data pipelines. Integration of generative AI for translation, text-to-speech, real-time feedback and vector search.

Cloud and Infrastructure
Hands-on experience with AWS, GCP, Kubernetes, Docker, CI/CD, observability and high availability systems targeting 99.99% SLA. Operation of distributed infrastructure across large server fleets and multiple data centres.

Leadership and Organisation
Scaling engineering teams from 1 to 50 engineers, structuring squads with Agile methodologies, hiring, mentoring and building a strong engineering culture.

Real-time Distributed Systems
Design and operation of large-scale WebSocket systems, real-time chat, video and live streaming platforms handling more than 3 billion loads per year.

Core Technology Stack
Proficiency in TypeScript, Node.js, Python, Go, Rust, PHP, React, Next.js, React Native, PostgreSQL, MongoDB, Redis, Elasticsearch and OpenSearch.

Predictive AI and Geospatial Analytics
Design of predictive AI platforms and data stacks, including capture-log and GPS analysis for digital compliance, trip optimisation, anomaly detection and environmental scoring.

E-commerce and Marketplace Platforms
Extensive experience rebuilding information systems, delivering multilingual marketplace integrations for platforms such as Zalando, Amazon, Cdiscount and La Redoute, plus search and catalogue systems.

Security Audits and High-traffic Web Platforms
Execution of security audits and architecture of high-traffic web platforms reaching up to 100 million page views per day across media, e-commerce and community products.

Experience

Professional experience10+ years
Freelancer since2005

Languages

EnglishFluentFrenchNative speaker

Project history

CTO and Co-founder

Slice
Monetised social platform for creators and influencers, designed and built from scratch. Designed the scalable full-stack architecture and multi-region GCP deployment, including real-time chat, video and live streaming. Integrated generative AI for translation, text-to-speech, real-time feedback, RAG and vector search. Grew product revenue from EUR 1K to EUR 100K MRR in under six months. Stack: GCP, Node.js, TypeScript, React/Next.js, PostgreSQL, RAG, Vector DB, LLM, Real-time.

CTO and Co-founder

Pontos
AI startup focused on predictive analytics for sustainable fishing across the value chain. Designed the predictive AI platform and data stack from scratch. Built capture-log and GPS analysis for digital compliance, trip optimisation, anomaly detection and environmental scoring. Stack: Predictive AI, Data pipelines, Geospatial/GPS, Python.

CTO and Partner

Semiologic
GraphComment and GraphDebate: real-time SaaS discussion platforms for media publishers. Built large-scale WebSocket systems with automated AI moderation. Operated distributed infrastructure across about 40 servers and multiple data centres with a 99.99% SLA. Handled more than 3 billion loads per year for clients including Orange, Les Echos, Nice-Matin, Le Phoceen and Il Post. Stack: Node.js, REST, GraphQL, WebSocket, MongoDB, Elasticsearch, Ansible.

Fractional CTO

Calimed
Healthtech engagement covering engineering audit, organisation and platform modernisation. Ran a complete technical and organisational audit and introduced Agile delivery and a modern CI/CD pipeline. Modernised the stack and supported French digital-health compliance; contributed to the company's sale to an international group. Stack: Fractional CTO, Agile, CI/CD, Digital Health.

CTO and Partner

Strime
Seed-stage B2B retail marketplace funded with EUR 2M. Redesigned the backend architecture and delivered a modern API using Clean Architecture and CQRS. Optimised AWS cloud costs, increased platform reliability and structured a six-engineer team. Stack: AWS, Clean Architecture, CQRS, Kubernetes, Node.js.

CIO and CTO

Winstore
International online fashion retailer. Rebuilt the information system across the storefront, back office and ERP. Delivered multilingual marketplace integrations for Zalando, Amazon, Cdiscount and La Redoute, plus search and catalogue systems. Stack: Symfony, Solr, MongoDB, Redis, Varnish.

CTO / CIO

Allopneus
French online tyre market leader with EUR 140M revenue and a top-ten national e-commerce position. Created and led the IT organisation, growing it from four to about 50 people during rapid expansion. Directed the platform rebuild, scalable API architecture and Agile organisation; led hosting, ERP and BI procurement. Stack: Symfony, Elasticsearch, MongoDB, Organisation leadership.

Developer to CTO

Earlier engagements (various clients and ventures)
More than 15 roles and engagements across high-traffic e-commerce, media and community products, reaching up to 100 million page views per day. Clients and ventures included Le Moniteur, PMU, Forumactif, ma-residence.fr, Doweb, Vivalio and Alyza Media. Stack: Web platforms, Security audits, High-traffic systems.

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