Principal Python Backend Engineer

### Job Description:

Note: Fidelity is not providing immigration sponsorship for this position.

Principal Python Backend Engineer

Bring a builder's mindset to Fidelity's Enterprise AI/ML Platform and help us scale the next generation of high-performance, production-grade backend systems. You will work on the core platform that connects tools, agents, data, and models—designing clean service abstractions, building resilient processing pipelines, shipping developer-friendly APIs and SDKs, and turning rapid prototypes into well-engineered, maintainable Python systems.

The Team

We hire exceptional, driven Python engineers first—people who take pride in clean code, fast learning, and high ownership. Deep knowledge of AI/ML is not a prerequisite; the domain knowledge and context can be learned on the job. What cannot be taught is the engineering rigour, the drive, and the instinct for simplicity that we look for.

What you’ll do

• Build the core AI/ML services running in Kubernetes and locally in 'Playground' mode
• Design clean abstractions over vector databases and multistep Search/Information Retrieval pipelines
• Own automated real-time data ingestion for RAG: connectors, streaming pipelines, chunking/embedding strategies, parallel processing, retrieval metrics, resilience & restartability while guaranteeing ACID integrity of processed data and elimination of redundant document processing.
• Ship developer-friendly APIs/SDKs, CLIs, and templates that make it trivial to develop agents, tools, and information retrieval pipelines at enterprise scale.
• Instrument everything: distributed tracing for services & agentic/tool sessions, retrieval quality metrics, performance metrics, resource usage and failure forensics.
• Turn rapid prototypes into resilient systems—pragmatic designs that are simple to use, which scale in hardware efficient manner, and above all as simple as possible.
• Read and distill open-source frameworks, keep what’s valuable,...