Senior GenAI Full-Stack Engineer - Brazil

Design and extend production-grade LLM applications and agentic workflows using

NestJS, XState v5, and the OpenAI SDK — flows include RAG, intent detection,

clarification, fulfillment, escalation, tool-use, and human-in-the-loop state machines

- Build and maintain the conversation-machine substrate: guard/action registries, flow

validation (ajv), DB-driven flow configs, and design-time tooling in Epicenter admin

- Build and evolve the AI systems behind Epic Support Assistant (ESA), the

player-facing support chatbot, and Agent Support Assistant, the AI copilot used by

customer support agents

- Integrate with MCP servers (Model Context Protocol) for tool-use and agentic behaviors

- Evaluate, benchmark, and tune models across providers including OpenAI, Gemini,

Anthropic, and future providers; own model selection decisions balancing quality,

latency, throughput, reliability, and cost

- Troubleshoot production LLM issues including hallucinations, retrieval failures, prompt

regressions, model drift, token inefficiencies, latency bottlenecks, and provider outages

- Build resilience mechanisms: retries, fallback routing, caching, streaming, rate limiting,

and provider routing

- Instrument and tune model quality using Langfuse (tracing, evals, prompt

management), evaluation datasets, A/B testing, prompt versioning, and production

telemetry

- Manage async workloads via