Senior Backend Engineer (.NET / AI Systems)

### Job Title: Senior Backend Engineer (.NET / AI Systems) **Position Type:** Full-Time **Remote Working Hours:** U.S. Business Hours #### About the Role We are hiring a Senior Backend Engineer (.NET / AI Systems) to own the entire technical function of an early-stage SaaS platform. This is a hands-on leadership role where you will write production code daily while making architecture, infrastructure, and AI system decisions for a platform operating at scale. You will be accountable for backend architecture, system reliability, AI pipelines, and guiding a small development team in a fast-moving startup environment. #### Responsibilities - **Backend Architecture & Engineering** - Design, build, and maintain a .NET 8.0 / C# backend using Clean Architecture and DDD principles - Own the architecture and codebase across 14+ independently deployed microservices - Deliver new features, refactor existing systems, and resolve performance bottlenecks - **AI Systems & LLM Orchestration** - Design and operate production-grade AI pipelines across multiple LLM providers - Optimize prompts and workflows for batch processing, personalization, and segmentation at scale - Manage rate limits, failover strategies, and cost optimization across AI providers - **Databases & Data Infrastructure** - Manage MySQL, Redis, and MongoDB in production environments - Oversee bulk writes, caching strategies, event streams, and analytics pipelines - Ensure data consistency and performance across distributed services - **Infrastructure, Reliability & Monitoring** - Own Linux-based infrastructure, CI/CD pipelines, and service deployments - Implement centralized logging, monitoring, alerting, and uptime tracking - Proactively identify and mitigate reliability and scalability risks - **API Integrations & System Resilience** - Manage 25+ third-party API integrations used in production - Design retry, fallback, and graceful degradation strategies - Ensure system stability when external providers fail or degrade - **Team Leadership & Engineering Standards** - Lead and mentor a small engineering team through code reviews and architectural guidance - Set and enforce engineering standards, workflows, and best practices - Collaborate closely with the founder on product direction and technical strategy #### What Makes You a Perfect Fit - You are a senior, hands-on engineer who enjoys owning systems end-to-end - You are comfortable being the most experienced technical person on the team - You balance fast execution with long-term architectural thinking - You take ownership of reliability, performance, and technical outcomes - You thrive in early-stage startup environments #### Required Experience & Skills - Deep expertise in .NET 8.0, C#, ASP.NET Core, and Entity Framework Core - Experience with distributed systems and independently deployed services - Strong production experience with MySQL, Redis, and MongoDB - Hands-on DevOps experience with Linux servers and CI/CD pipelines - Experience managing large numbers of third-party API integrations - Proven experience building and operating AI/LLM systems at scale.