Theodoros Margazas

Principal Software Architect & Engineering Leader • AI / LLM Systems • High-Transaction & Regulated Platforms

Software architect with over two decades of experience designing and shipping production LLM/RAG pipelines, event-driven architectures, and high-availability platforms in high-transaction and regulated environments.

LLM & RAG Pipelines ((Claude, GPT-4o, Gemini, DeepSeek, Ollama) Hybrid Search (kNN + BM25) PHP 8.3 / Symfony 7, ASP.NET/C#, Python / FastAPI, C/C++ PostgreSQL, SQL Server, Oracle, MySQL/MariaDB AWS (OpenSearch, DMS, SQS, ECS)
Core Expertise
LLM & RAG Architecture
End-to-end RAG pipeline design, hybrid kNN + BM25 retrieval, grounded generation, multi-provider LLM integration (Claude, GPT-4o, Gemini, DeepSeek, Ollama), Amazon Bedrock, pgvector, and agentic workflow design[cite: 1].
Payments & Compliance
Multi-rail payout orchestration (Adyen, Swapped Commerce) across 12 currencies and 3 cryptocurrencies, integrated with Trulioo KYC, Chainalysis AML, and real-time audit dashboards[cite: 1].
Distributed Systems
Amazon SQS, Apache Kafka, Symfony Messenger, outbox pattern design, event-driven architectures, and exactly-once processing at high daily transaction volumes[cite: 1].
Cloud & Infrastructure
AWS ecosystem (ECS Fargate, Aurora, OpenSearch, Bedrock), Terraform, Docker containerization, CI/CD via GitHub Actions, and high-availability platform architecture[cite: 1].
Search & Machine Learning
FastAPI NLP microservices (BERT / spaCy / MiniLM), hybrid search routing, behavioral personalization engines, and Gradient Boosting models for price prediction[cite: 1].
Engineering Leadership
Direct team ownership (engineers + vendors), technology roadmap authorship, architectural governance, and multi-year budget and P&L management[cite: 1].