— Premium Advisory Tech Copmpagny · Paris
Vesperian architects modern agentic infrastructure for enterprises that intend to lead. We work with a small number of clients each year. On purpose.
What We Do
We not only deliver decks and align your teams. We also deliver working agentic systems, deployed in your environment, owned by your team.
01 — Flagship
35–60k€
In-depth architectural diagnostic of complex, strategic or aging information systems. We analyze your current architecture across business, technical and organizational dimensions, and deliver a clear target architecture with a prioritized roadmap. Ideal before major transformations, replatforming, or when architecture becomes a bottleneck. We use AI for AI retro-documentation and retro-engineering.
02 — Flagship
35–60k€
Complete transition from conversational AI experiments to real production-grade agentic systems. We design the complete architecture, orchestration layers, agent collaboration patterns, governance model and execution roadmap.
03 — Recurring
Rate on demand
Part-time strategic technical leadership. We join your team 2 to 3 days per week to guide major technical decisions, architecture direction and transformation programs with an external, experienced perspective.
04 — Flash
12–20k€
Focused 2-to-4-week deep-dive on a specific architectural challenge — whether it's integration strategy, data platform modernization, frontend/backend decoupling, sovereignty options, or security architecture.
05 — Flash
8–15k€
High-impact executive workshops to support critical technology decisions. Tech trends / R&D, Build vs Buy analysis, technology stack evaluation, AI opportunity assessment, or sovereign cloud strategy.
Complex systems delivered
Years of experience
Years at OCTO Technology leading Software Engineering practice
Production deployments
About us
We are a small team of former CTOs, architects and engineers. We've built Complex Systems and Architectures, shipped agents. We work with a tight roster of clients — not because we have to, but because great AI work demands real depth.
Antoine Chantalou
Founder, Vesperian
With over 13 years at OCTO Technology, he led the Tech Trends program, analyzing emerging technology shifts for large organizations. Specialized in Complex Systems Architecture & Technology Strategy, he helps companies master their most strategic and challenging technical environments. His approach combines deep technical expertise with a clear strategic vision, covering business, architecture, and organizational dimensions simultaneously.
Selected Work
Agentic Workflow System
Agentic Systems Architecture
AI Architecture & Design
Complex Systems Assessment
Enterprise Integration
Strategic Technology Advisory
How We Work
01 — Fullstack scoping
Across three critical dimensions: Business (Vision, high-value use cases, KPIs), Architecture (Target agentic architecture, orchestration and technical stacks), Organization.
02 — Engineer
Iterative agentic development with full transparency. You see the system evolve. Nothing is a black box. Every decision is explained.
03 — Deploy
Production deployment, documentation, and knowledge transfer. Your team owns what we've built. We stay until they do.
What Clients Say
Insights
May 2025
April 2025
March 2025
Work with us
We take on a limited number of engagements each year. If you need help on Complex Systems Architecture, Technology Strategy, Agentic Systems, Sovereignty — we'd like to hear from you.
Response within 48 hours · Paris, working globally