Open WebUI Engineer — Self-Hosted LLM Platform, Deployment & Production Support

Remote · Freelance · Part-time or Project-based / Consulting We are looking for a senior engineer with deep Open WebUI experience to help deploy, stabilize, and optimize real-world self-hosted LLM environments running Open WebUI in production. This is not a "spin up a demo" role — it's focused on deep troubleshooting, integration health, and operational reliability. You'll work with real client cases through Hossted.com's open-source consulting practice, analyzing deployment configurations, logs, and performance metrics to identify issues and deliver practical, production-ready solutions. What You'll Work On: · Investigating deployment and startup failures across Docker, Kubernetes, and pip-based Open WebUI installations managed via Hossted.com. · Diagnosing reverse proxy and WebSocket issues — hanging chats, broken streaming, and Nginx/Traefik misconfigurations. · Troubleshooting model connectivity to Ollama, vLLM, LiteLLM, and other OpenAI-compatible API backends. · Debugging RAG pipelines — document ingestion, embeddings, vector store (ChromaDB/pgvector) behavior, and web search integration. · Resolving authentication and access issues — OAuth/SSO, RBAC, and user/group permission configurations. · Supporting database setup and migrations (SQLite → PostgreSQL) and persistent storage configuration. · Building and debugging custom Pipelines and Functions (Python plugin framework). · Optimizing performance and scaling for multi-user concurrent load. · Identifying bottlenecks across the full stack: browser → reverse proxy → Open WebUI → inference backend → data layer. Requirements: · Proven hands-on experience deploying and operating Open WebUI in production environments. · Strong understanding of containerized deployments — Docker, Docker Compose, and Kubernetes. · Experience integrating LLM backends (Ollama, OpenAI-compatible APIs) and diagnosing connection failures. · Familiarity with reverse proxy configuration, WebSocket handling, HTTPS/TLS, and CORS. · Comfortable troubleshooting using container logs, environment variables, and metrics. · Working knowledge of Python for Pipelines/Functions debugging. · Comfortable working with open-source technologies in diverse client environments. · Strong debugging and root-cause analysis skills. · Strong written and spoken English — you will communicate directly with Hossted.com clients. Nice to Have: · Experience with RAG architectures and vector databases (ChromaDB, pgvector, Qdrant). · Familiarity with inference servers and model serving (vLLM, LiteLLM, TGI). · Experience with PostgreSQL setup and migrations for self-hosted apps. · SSO/OAuth integration experience (Keycloak, Authentik, Google/Microsoft). · Monitoring background — Prometheus, Grafana, or equivalent for application observability. · Basic DevOps / automation skills (Ansible, Terraform, Helm). About Hossted: Hossted is a U.S.-based company working with 300+ open-source technologies. We help companies solve complex technical issues through expert consulting — fast, practical, and hands-on. This role is part of our open-source expert network, supporting clients who run Open WebUI as a critical component of their self-hosted AI infrastructure. Best Fit: Senior engineers with a passion for open-source technologies who enjoy digging into self-hosted AI platform behavior, understand the deployment and integration challenges of LLM infrastructure, and can resolve complex production issues in real client environments. To Apply: Please include a brief note describing an Open WebUI environment you have deployed or supported: deployment method, inference backend, approximate user scale, and any significant integration, performance, or stability issues you have resolved.