Senior Backend Engineer, AI PlatformRemote - US only • Full-time
Are you passionate about building AI products people actually use, serving millions of users? Do you want to help lead the AI engineering effort at this country's fastest-growing social media company that champions free speech? You'll be building AI-based features into a platform serving millions of users.
About the RoleYou'll work directly with the platform architect and other developers to bring deep, hands-on LLM-stack expertise: you've built these systems before, you know where they break, and you know what "good" looks like in production.
The work is greenfield. You won't be maintaining someone else's pipeline - you'll be standing up the core AI infrastructure for a platform with millions of active users, and shaping the engineering practices around it as the team grows.
What We're Looking For- 5+ years of backend engineering experience in a statically typed language (Go, Java, Kotlin, C#)
- You've shipped production LLM-backed features - retrieval-augmented generation, streaming responses, tool use - and lived with them after launch
- Hands-on experience with the LLM serving stack: routing across multiple model providers, failover, token streaming, and cost/usage metering
- Experience building retrieval systems: vector search, embedding pipelines, context assembly, and citation-backed answers
- You think in failure modes: hallucination, retrieval misses, provider outages, cost blowouts - and you build the instrumentation to catch them
- Pragmatic about evaluation - you know how to measure whether AI answers are actually good (relevance, safety, source quality) with simple, repeatable tests, not just academic benchmarks
- Strong API design instincts; comfortable owning a service end to end, from schema to deploy to on-call
- US-based and authorized to work in the United States
Nice to Have- Go (strongly preferred)
- Python
- Experience with LLM gateways or serving infrastructure (LiteLLM, vLLM, TGI, or similar)
- Vector databases (Qdrant, pgvector) and embedding pipelines
- Fine-tuning open-weight models (LoRA or full fine-tunes) and the eval discipline that goes with it
- Content moderation or safety tooling experience• Familiarity with Ruby on Rails or React/TypeScript (you'll integrate with both)
Our StackGo, Ruby on Rails, Python, React/TypeScript, PostgreSQL, Redis, RabbitMQ. Services deployed across multiple data centers.
