Senior Backend Engineer (.NET & AI/ML)

Overview

Senior Backend Engineer - .NET and AI/ML

Backend Systems

Responsibilities

• Backend Engineering
  • Design, develop, and maintain backend services, REST APIs, and gRPC microservices using .NET Framework and .NET Core / .NET 8+ in C#.
  • Build and evolve gRPC service contracts using Protocol Buffers (.proto), including streaming, error handling, and versioning across services and API gateways.
  • Build and optimize data layers across SQL Server, MongoDB, and Elasticsearch, including indexing, query tuning, sharding, and relevance tuning.
  • Apply DDD, CQRS, MediatR, and Minimal API patterns; structure code into Aggregate Roots, Commands/Handlers, and endpoints consistent with engineering conventions.
  • Improve performance via caching, async patterns, distributed processing, and event-driven messaging.
  • Build cloud integrations across AWS and Azure (compute, storage, queues, observability). Both clouds are equally important.
  • Contribute to CI/CD pipelines, GitHub Actions workflows, automated testing, containerization (Docker), and deployment automation.
  • Uphold code quality, observability, structured logging, and operational excellence.

• AI/ML Engineering
  • Design and ship AI/ML-powered backend features such as search ranking, recommendations, personalization, and intelligent listing experiences.
  • Build and operate RAG pipelines, vector search, embeddings stores, and LLM-powered services, integrated cleanly into our .NET ecosystem.
  • Build, extend, and maintain our MCP (Model Context Protocol) server, including designing MCP tools, managing context windows, and exposing backend capabilities to AI agents and assistants.
  • Integrate ML models into production via inference APIs, ranking services, gRPC endpoints, and personalization endpoints.
  • Use GA4 / Segment event data to power behavioral signals, personalization, and ranking features.
  • Evaluate and apply emerging AI tooling (LLM providers, agent frameworks, vector DBs) to solve real product problems.
  • Apply AI-assisted development tools (GitHub Copilot, Copilot Coding Agent, Copilot Spaces) in day-to-day engineering.

Who You Are

• Backend Engineering
  • 7+ years building production backend systems with .NET Framework and .NET Core / .NET 6+.
  • Strong expertise in REST API design, distributed systems, and microservices architecture.
  • Hands-on experience designing and operating gRPC services in production with Protocol Buffers (.proto), including service contracts, code generation, error handling, deadlines, and inter-service communication patterns.
  • Deep SQL Server experience: complex queries, indexing, stored procedures, and performance tuning.
  • Hands-on production experience with MongoDB and Elasticsearch.
  • Production experience on both AWS and Azure (compute, queues, storage, observability).
  • Solid grasp of Git/GitHub, CI/CD, Docker, automated testing, and DevOps fundamentals.
  • Experience with high-traffic, performance-sensitive consumer web platforms.

• AI/ML Engineering
  • 2+ years of hands-on experience shipping AI/ML features into production, such as ranking, personalization, recommendations, or LLM-powered services.
  • Strong working knowledge of LLMs, embeddings, vector databases, and RAG architectures.
  • Hands-on experience with MCP (Model Context Protocol), including designing and configuring MCP tools, managing context windows, and integrating MCP servers into backend services.
  • Experience integrating inference APIs and ML models into production backends.
  • Familiarity with prompt engineering, evaluation, and guardrails for LLM-based systems.
  • Experience with GA4 / Segment event data for personalization or ranking is a plus.
  • Exposure to Python ML tooling (LangChain, Hugging Face, SageMaker, Vertex AI, MLflow) is a plus.

Preferred Qualifications

• Experience with search relevance, ranking, or recommendation systems at scale, especially on Elasticsearch.
• Experience modernizing legacy .NET (Framework to .NET Core / .NET 8+) or migrating monoliths to gRPC-based, cloud-native architectures.
• Familiarity with distributed caching (Redis), event-driven systems (Kafka / SNS / Azure Service Bus), API Gateways, and CQRS/MediatR.
• Experience building MCP servers, AI agents, or internal AI developer tools.
• Real estate, marketplace, or classifieds domain experience.

Tech Stack

• Backend: .NET Framework, .NET Core / .NET 8+, C#, ASP.NET Minimal APIs, gRPC, Protocol Buffers, MediatR
• Databases: SQL Server, MongoDB, Elasticsearch
• Cloud: AWS, Azure
• AI/ML: LLMs, RAG, Vector DBs, MCP (Model Context Protocol), LangChain, MLflow, Python (optional)
• DevOps: GitHub, GitHub Actions, Docker, CI/CD, observability tooling
• Analytics: GA4, Segment
• Frontend (adjacent awareness): Next.js, React, TypeScript

Why People Love Working Here

• We offer meaningful work and opportunities for career growth
• Competitive Salary
• 100% paid by Zonda health benefit package
• 100% Company paid Life Insurance coverage
• Paid vacation and general holidays
• Employee Assistance Program (EAP)
• Live Meditation Sessions
• Employee Recognition Platform
• Virtual Wellness Program
• 100% Hybrid – and always will be!

Inclusion & Equal Opportunity Employment

Zonda is proud to be an Equal Opportunity Employer committed to diversity, inclusion & belonging. Here at Zonda, we are interested in every qualified candidate who is eligible to work in Canada.