Senior Full-Stack AI Engineer

Senior Full-Stack AI Engineer

Location: Brazil (Remote)

About Sphise Technologies

Sphise Technologies is a global outsourcing and talent solutions company, partnering with high-growth businesses to build strong, high-impact teams across finance, technology, and operations.

Our trusted high-growth technology partner is building a production AI platform that transforms disconnected data into measurable business growth. With customers already onboarding and the platform live in production, they are hiring a Senior Full-Stack AI Engineer to scale their next-generation AI systems.

Position Overview:

We are seeking a Senior Full-Stack AI Engineer to own the intersection of agentic AI and modern web development. You will build the intelligent backend powering a multi-agent system and the interactive frontend delivering real-time AI experiences. This role requires strong architectural judgment — the platform runs on Vercel, and decisions around caching, bandwidth, cost efficiency, and production reliability are critical.

If you are excited about building AI agents that work in production, designing streaming chat experiences, and solving complex orchestration challenges, this is the opportunity for you.

What You'll Do:

- Design and optimize production prompts for LLMs and build multi-agent workflows with smart routing, specialization, and human-in-the-loop approval gates - Build stateful agent workflows with planning, execution, and observation loops — making sure agents reliably follow structured steps even when users go off-script - Create streaming chat UIs with real-time rendering, tool call visualization, and interactive artifacts - Connect agents to analytical databases for live data retrieval, SQL generation, and knowledge base access through RAG pipelines - Own performance across the full stack — caching strategies, bandwidth optimization, and keeping Vercel costs under control - Implement LLMOps practices including prompt versioning, observability, and cost tracking.

What You Bring

- 3–5+ years of progressive experience in full-stack development. - Strong TypeScript skills across frontend, backend, and agent logic - Production experience with React or Next.js (App Router, Server Components, API routes) - Hands-on work with LLM agent frameworks — LangGraph, CrewAI, AutoGen, or custom agent loops - Production prompt engineering: system prompts, chain-of-thought reasoning, tool-calling patterns - Direct experience with LLM APIs (OpenAI, Anthropic, or open-source models) - Bachelor's degree in Computer Science, Engineering, or equivalent practical experience

Nice to Have

- Experience with Vercel AI SDK (useChat, streamText, streaming patterns) - Familiarity with durable workflow engines like Trigger.dev or Temporal - Experience with RAG pipelines, vector databases, or knowledge retrieval systems - Background in performance optimization for Vercel-hosted applications - Experience at an early-stage startup or building a product from 0 to 1.

Benefits:

- Competitive salary to recognise and reward your achievements. - Flexible work environment. - Opportunities for professional and personal growth.