Sylvain Leroy — Cloud & Application Modernization Architect

Sylvain Leroy

Cloud & Application Modernization Architect

I help software companies, banks and enterprise teams migrate, modernize and optimize complex platforms across AWS, GCP and cloud-native environments.

20+ years in software modernization · AWS & GCP certified · SaaS, banking, insurance and enterprise platforms

Cloud and Application Modernization

Field notes on cloud & modernization

I write about cloud migration, modernization strategy, legacy transformation, architecture complexity, performance optimization and the real-world constraints of enterprise IT.

From the blog

Latest articles

Fresh field notes on cloud, modernization, data engineering and AI — published as I go.

AionUi: A GUI That Wraps Your CLI AI Agents Instead of Replacing Them

artificial-intelligence

AionUi: A GUI That Wraps Your CLI AI Agents Instead of Replacing Them

AionUi wraps CLI AI agents like OpenCode and Claude Code — an honest review of the open-source GUI that respects the agent ecosystem instead of reinventing it.

6 min read

Basic Memory: Giving My AI Assistant a Memory That Lives in My Obsidian Vault

artificial-intelligence

Basic Memory: Giving My AI Assistant a Memory That Lives in My Obsidian Vault

basic-memory gives my AI assistant persistent memory as plain Markdown synced to my Obsidian vault — transparent, editable, and a real accuracy boost. Part 6 of the local-AI stack series.

6 min read

Building a Private Local-AI Stack: Why and How

artificial-intelligence

Building a Private Local-AI Stack: Why and How

How I built a private local-AI stack that automates real work — email triage, recall, drafting — while keeping sensitive data on my own hardware. Part 1: the use case and the sensitivity boundary that drives every choice.

6 min read

LightRAG as a Personal Knowledge Base for AI Agents

artificial-intelligence

LightRAG as a Personal Knowledge Base for AI Agents

How I run LightRAG as a local semantic index over my personal documents, wired into AI agents via MCP — the architecture, the tuning, and the silent outage that taught me health checks lie. Part 2 of the local-AI stack series.

7 min read

OpenRouter and the Case for Safe Models

artificial-intelligence

OpenRouter and the Case for Safe Models

One API, many models, and provider pinning: why OpenRouter sits at the non-PII half of my local-AI stack, and how I draw the line that sensitive data never crosses. Part 3 of the local-AI stack series.

6 min read

Right-Sizing a Local LLM to Your Laptop with llmfit

artificial-intelligence

Right-Sizing a Local LLM to Your Laptop with llmfit

The PII half of my stack runs a local model — but which one fits 16 cores and 20 GiB? llmfit scores every model against your actual hardware so you stop guessing. Part 4 of the local-AI stack series.

5 min read

Ready to start?

Need help modernizing a platform, preparing a cloud migration, or reviewing your architecture?

Let's talk about your platform, your constraints, and where AWS, GCP or cloud-native architecture can move the needle.

Get in Touch