Safu Harry

Engineering Journal · Open Source · Architecture

Systems built to be reused.

Selected engineering work across backend architecture, AI systems, machine learning, and quantitative development. The focus is not only on applications, but on building software foundations that can be extended, tested, packaged, and reused.

02 · AI SystemsActive Development

PAssist

A provider-agnostic AI platform built around the same backend engineering principles. PAssist combines a modular FastAPI service with identity and JWT authentication, persistent conversations, AI provider abstraction, local Ollama integration, retrieval, tools, memory, and extensible domain boundaries.

Identity → JWT authentication → sessions ↓ FastAPI application → domain modules ↓ AI provider contract → Ollama / compatible APIs ↓ SQLAlchemy 2.x → Alembic → PostgreSQL
PythonFastAPIJWTArgon2SQLAlchemyPostgreSQLOllamaLLMsRAGTool Calling
Explore PAssist →

The engineering philosophy

Infrastructure first. Domain second.

FastApiBackbone is the reusable infrastructure substrate: asynchronous application structure, database lifecycle, migrations, configuration, logging, health checks, and clean extension points. It is deliberately domain-neutral so that another Python service can adopt the foundation without inheriting assumptions from a particular product.

PAssist demonstrates the next layer: a concrete application domain built with identity, security, AI provider abstraction, conversations, tools, knowledge retrieval, and memory. Together, the projects show the progression from reusable backend infrastructure to a complex AI-enabled application.