Hybrid AI Backend Engineer (Python, Flask/FastAPI) Toronto

Marsh; Toronto; Hybrid; CAD 110,000 - 170,000; Full time

Job summary

Marsh in Toronto, ON is seeking an AI Developer to design, build, and maintain scalable backend services and AI/LLM APIs using Python, Flask and FastAPI. This hybrid role requires in-office presence at least three days per week.

You will implement REST and WebSocket APIs, RAG pipelines, tool-calling workflows, and model evaluation across GPT and open-source solutions, while ensuring security and performance in production-grade systems.

Qualifications

• 3+ years in a corporate IT environment.
• 1+ year in AI, machine learning, Python, Flask, and FastAPI, or a combination of at least three of these areas, with AI required; strong software design, debugging, and performance profiling skills.
• Solid knowledge of SQL Server and PostgreSQL, including schema design, indexing, optimization, and ORM experience.
• Experience maintaining security, privacy, and compliance best practices, including secret management, data handling, and access control.
• Strong commitment to writing secure, reliable, well-documented code that meets quality standards.

Responsibilities

• Design, build, and maintain scalable backend services and APIs in Python, with a focus on Flask and FastAPI.
• Write clean, efficient Python code with strong attention to performance, reliability, and security.
• Develop production-ready AI and LLM APIs, including REST and WebSocket streaming, authentication, and access control.
• Implement LLM solutions using GPT and open-source models, including prompt design, evaluation, versioning, and cost/performance optimization.
• Build and maintain RAG pipelines, including ingestion, embeddings, vector search, and agent/tool-calling workflows.
• Integrate external and internal tools and data sources for LLM-based agents, such as databases, APIs, file systems, and messaging platforms.
• Work with SQL Server and PostgreSQL, including schema design, efficient queries, transaction handling, and ORM tools like SQLAlchemy.
• Apply classical machine learning and statistical techniques when they offer a simpler or more cost-effective solution.

Skills

Python

Flask

FastAPI

AI/ML

SQL Server

PostgreSQL

Security

Performance profiling

Code reliability

Tools

Docker

Kubernetes

GitHub Actions

SQLAlchemy

REST APIs

WebSocket

Job description

Marsh in Toronto, ON is seeking an AI Developer to design, build, and maintain scalable backend services and AI/LLM APIs using Python, Flask and FastAPI. This hybrid role requires in-office presence at least three days per week.

You will implement REST and WebSocket APIs, RAG pipelines, tool-calling workflows, and model evaluation across GPT and open-source solutions, while ensuring security and performance in production-grade systems.