Senior AI Fullstack Engineer (Next.js & LLM)

Blazity is a team of React.js and Next.js experts building modern, API-first digital products. We partner with enterprise clients as trusted technology advisors, delivering solutions that span complex web platforms, e-commerce ecosystems, and custom software products.

• 8+ years of experience as a consultant / forward deployed engineer
• Strong experience with Next.js (App Router), React, TypeScript
• Deep understanding of Server vs Client Components (RSC), streaming, caching, revalidation, Server Actions
• Experience with Vercel AI SDK, LangGraph, MCP
• Experience building RAG systems
• Experience with Claude extended thinking, prompt caching, Batch APIs
• Proven experience shipping LLM-powered features to production
• Hands-on experience with Anthropic and OpenAI APIs (messages, tool use, streaming)
• Practical experience with prompt engineering (structured output, few-shot, XML), tool calling / agent workflows, multi-turn orchestration
• Understanding of token economics (input/output costs, context window), latency vs quality trade-offs
• Experience with prompt evaluations (LLM-as-judge, rule-based), handling hallucinations and failure modes
• Ability to design robust AI systems, not just prototypes
• Strong ownership mindset
• Experience working directly with clients
• Clear communication and structured thinking (English C1)
• Ability to make decisions in ambiguous environments

• Build scalable web applications using Next.js (App Router) and TypeScript, ensuring high performance and clean architecture.
• Develop and orchestrate LLM-powered features using Anthropic and OpenAI APIs, focusing on tool use and streaming.
• Design autonomous agent loops and multi-turn workflows, knowing when to use a structured pipeline versus a dynamic agent.
• Manage token economics (pricing, context windows) and implement prompt evaluations (LLM-as-judge, rule-based) to ensure system reliability.
• Work directly with senior engineers, founders, and client teams to shape AI capabilities from concept to production.