Senior C# .NET AI-Driven Backend Architect (Hybrid)

Mongoose Gray; Toronto; On-site; CAD 95,000 - 130,000; Full time

Job summary

Mongoose Gray in Toronto is seeking a Senior C# .NET Developer to design and scale AI-enabled backend services within a fast-paced SaaS scaleup. You will own the full lifecycle of AI features, from retrieval-augmented generation to agentic workflows, leveraging Claude Code and AWS to ship robust systems.

You will collaborate with Product, Data and Platform teams to shape how AI powers our core product while ensuring observability, reliability and cost discipline as we scale.

Qualifications

• Senior C# .NET Developer with experience in fast-paced SaaS scaleups.
• Proficient in building scalable C# .NET services on AWS.
• Experience with retrieval-augmented generation and vector search.

Responsibilities

• Own end-to-end AI feature lifecycle from concept to production.
• Design scalable backend services powering AI-driven features.
• Work with Product, Data, and Platform teams to deliver value.
• Architect RAG pipelines and multi-step agentic workflows.
• Deploy and monitor AI infrastructure on AWS.

Skills

C# .NET

AWS

AI/ML

RAG pipelines

Vector search

LLM integration

Backend architecture

Observability

Claude Code

Tools

AWS Lambda

ECS/EKS

S3

Bedrock

RDS

Job description

Mongoose Gray in Toronto is seeking a Senior C# .NET Developer to design and scale AI-enabled backend services within a fast-paced SaaS scaleup. You will own the full lifecycle of AI features, from retrieval-augmented generation to agentic workflows, leveraging Claude Code and AWS to ship robust systems.

You will collaborate with Product, Data and Platform teams to shape how AI powers our core product while ensuring observability, reliability and cost discipline as we scale.