April 24, 2026
Frontend Engineer
Senior • Hybrid
120,000 - 250,000 USD/yr
Seattle, WA
Who We Are
Lightning AI is the company behind PyTorch Lightning. Founded in 2019, we build an end-to-end platform for developing, training, and deploying AI systems—designed to take ideas from research to production with less friction.
Through our merger with Voltage Park, a neocloud and AI Factory, Lightning AI combines developer-first software with cost-efficient, large-scale compute. Teams get the tools they need for experimentation, training, and production inference, with security, observability, and control built in.
We serve solo researchers, startups, and large enterprises. Lightning AI operates globally with offices in New York City, San Francisco, Seattle, and London, and is backed by Coatue, Index Ventures, Bain Capital Ventures, and Firstminute.
Our Values
-
Move Fast: We act with speed and precision, breaking down big challenges into achievable steps.
-
Focus: We complete one goal at a time with care, collaborating as a team to deliver features with precision.
-
Balance: Sustained performance comes from rest and recovery. We ensure a healthy work-life balance to keep you at your best.
-
Craftsmanship: Innovation through excellence. Every detail matters, and we take pride in mastering our craft.
-
Minimal: Simplicity drives our innovation. We eliminate complexity through discipline and focus on what truly matters.
What We're Looking For
We are looking for a frontend engineer to help us develop and scale the UI and frontend infrastructure of the Lightning AI platform.
We want someone who can take ownership of key features and drive development from end to end while collaborating with a super-smart team of engineers, product managers, and designers. Here, you'll build from proof of concept to release with a focus on speed, quality, and iteration.
With over 10,000 organizations building with Lightning, you'll have a unique opportunity to impact how the world builds and deploys AI to production.
This is a hybrid role based in our San Francisco office with in-office requirements of 2 days per week. The salary range for this role is $120,000 - $250,000.
What You'll Do
- Write readable/testable/efficient code in React and Redux and master our technology stack to deliver new features, improve system stability, and increase overall performance.
- Partner with engineering and product leaders on developing the user interface and frontend infrastructure while using your experience to set the technical direction for large projects.
- Evaluate, strengthen, and document technical architecture, tools, and processes.
- Champion software quality, implement automation, drive continuous delivery, and reduce time to production while proactively reducing technical debt.
- Mentor and coach engineers on system design, operating in high uncertainty, and problem-solving to create a supportive, inclusive environment in which each engineer can grow.
What You'll Need
- Proficiency in React, javascript and typescript. Strong understanding of software engineering principles and lifecycle.
- Hands-on experience as a frontend engineer in a SaaS technology company
- Proven ability to take ownership of key features and drive end-to-end development
- Communication and collaboration with engineers, product managers, and designers
- Ability to operate in high uncertainty and rapidly changing environments
Benefits and Perks
We offer competitive base salaries and equity with a 25% one year cliff and monthly vesting thereafter. For our international employees, we work with our EOR to pay you in your local currency and provide equitable benefits across the globe.
In the US, we offer:
- Medical, dental and vision
- Life and AD&D insurance
- Flexible paid time off including winter closure
- Paid family leave benefits
- $500 one time home office stipend
- $1,000 annual learning & development stipend
- 100% Citibike membership (NYC only)
- $45/month gym membership
- Additional various medical and mental health services
At Lightning AI, we are committed to fostering an inclusive and diverse workplace. We believe that diverse teams drive innovation and create better products. We provide equal employment opportunities to all employees and applicants without regard to race, color, religion, gender, sexual orientation, gender identity, national origin, age, disability, veteran status, or any other protected characteristic. We are dedicated to building a culture where everyone can thrive and contribute to their fullest potential.
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🏢 Summary: Frontend Engineer role focused on building production-ready Next.js SSR applications that power enterprise AI interfaces at scale. The position involves architecting complex state management, real-time LLM streaming experiences, and high-performance data-heavy UIs integrated with enterprise systems. You will own features end-to-end, ensuring accessibility, security, and performance for mission-critical AI-driven workflows. 🗂️ Requirements: 5+ years frontend engineering experience, 3+ years experience with React and modern JavaScript/TypeScript, Production experience with Next.js SSR applications, Advanced TypeScript expertise, Experience with complex state management in real-time or multi-tenant applications, Experience building enterprise applications with i18n, accessibility, and security standards, Experience building AI/LLM interfaces with streaming or real-time interactions, Proven ability to optimize high-load, data-heavy applications, Strong expertise in modern CSS (Tailwind CSS or CSS-in-JS), Experience with observability and monitoring tools, Experience using AI coding assistants in development, Upper-Intermediate English proficiency 📃 Skills: React, Next.js, TypeScript, JavaScript, SWR, REST, WebSockets, Tailwind, CSS, Storybook, ReactFlow, Highcharts, Playwright, Datadog, Sentry, Elasticsearch, DynamoDB, PostgreSQL, Aurora, AI, LLM 🏢 Description: As a Frontend Engineer at Shelf, you’ll craft the interfaces that make enterprise AI accessible and trustworthy. While others are building chatbots, we’re solving the harder problem: how do you build UIs that help users confidently navigate AI-powered systems processing millions of documents, while maintaining enterprise-grade reliability? You won’t just build React components — you’ll architect production-ready Next.js applications that handle high-load scenarios with complex states, real-time AI streaming, and multiple layers of enterprise functionality. Every interface decision you make directly impacts how knowledge workers at the biggest companies in the market interact with their most critical information. This is frontend engineering at its most demanding. You’ll tackle challenges like building real-time streaming interfaces for LLM responses, architecting state management for concurrent AI operations across multiple tenants, creating accessible interfaces for complex knowledge graphs with thousands of nodes, and ensuring blazing fast interactions even with petabytes of searchable content. Your components will bridge everything from enterprise authentication systems to cutting-edge AI models, requiring both sophisticated technical skills and sharp product instincts. We obsess over frontend quality because we’re building the trust layer for AI itself. When your interfaces gracefully handle edge cases, provide clear feedback during AI processing, and remain performant under load, you’re not just meeting UX standards — you’re directly enabling users to trust AI-powered answers and make critical business decisions with confidence. You’ll work on production SSR applications serving thousands of enterprise users, implementing localization for global markets, ensuring accessibility compliance, and maintaining security standards that pass SOC 2 audits. Your code will integrate with our Elasticsearch clusters, DynamoDB tables, and Aurora PostgreSQL databases through the largest park of REST APIs, handling real-time websocket updates for AI streaming and collaborative features. We’re a product company that ships fast without compromising on lasting quality. You’ll work alongside proactive, ever-learning engineers who actively use AI coding assistants (OpenAI Codex, Claude Code) to accelerate development. We build custom MCP servers, implement DSPy pipelines for LLM optimization, and experiment with different AI tools for implementation. In our environment, AI isn’t just what we build — it’s how we build. The best engineers we know are drawn to problems that matter. If you’re excited by the challenge of building interfaces that make the AI revolution actually usable and trustworthy for enterprise users, this role offers the rare combination of technical depth, meaningful impact, and the prestige of solving UX patterns that the industry hasn’t figured out yet. Responsibilities Design and implement production-ready Next.js SSR applications with complex state management, handling high-load scenarios and real-time AI interactions at scale Build interfaces for AI-powered features including streaming LLM responses, semantic search across millions of documents, interactive knowledge graphs, intelligent content recommendations, and AI agentic builders Architect component libraries and maintain our design system in Storybook, ensuring reusability, accessibility, and consistent UX patterns across the platform Develop enterprise-grade functionality including multi-language support, accessibility compliance, cross-browser compatibility, and security implementations that meet SOC 2 standards Create comprehensive technical specifications and component API designs that clearly communicate interface decisions, performance trade-offs, and accessibility considerations Build and optimize data-heavy UIs using React Flow for node-based graphs, Highcharts for analytics visualizations, and custom virtualization for handling large datasets Instrument components for performance monitoring, track Core Web Vitals, implement error boundaries, and build automated visual regression tests with Playwright Take full ownership of the features you build, monitoring their performance in production, optimizing bundle sizes, and ensuring they scale gracefully as user load grows Work with SWR for intelligent data fetching, caching, and revalidation strategies that minimize API calls while keeping UIs responsive and data fresh Integrate with backend services via REST APIs, handle websocket connections for real-time updates, and implement optimistic UI patterns for seamless user experiences Leverage AI coding assistants to accelerate development while maintaining high code quality, and contribute to building internal AI agents that automate frontend workflows Stay current with React ecosystem best practices, Next.js updates, AI UX patterns, and modern frontend architecture—experiment with new approaches and share findings with the team Contribute to our engineering standards and practices through thoughtful code reviews, mentor colleagues on frontend best practices, and actively participate in our culture of continuous learning Requirements Over 5 years of professional frontend engineering experience, including more than 3 years specializing in React and modern JavaScript/TypeScript Production Next.js experience — you’ve built and shipped SSR applications at scale, understand app router patterns, server components, and the trade-offs between SSR, SSG, and CSR Deep TypeScript expertise — you write type-safe code with generics, utility types, and advanced patterns. Complex state management — hands-on experience architecting state solutions for challenging scenarios: real-time collaboration, optimistic updates, multi-tenant data isolation, and large-scale data synchronization Enterprise application development — you’ve built applications with localization (i18n), accessibility, security best practices, and compliance requirements. You understand the complexity beyond “making it work” AI/LLM interface experience — you’ve built interfaces for AI-powered features: streaming token responses, chat UIs, semantic search, or similar real-time AI interactions High-load optimization — proven track record optimizing applications for performance under heavy traffic, large datasets, and concurrent operations. You monitor Core Web Vitals and know how to improve them Modern CSS mastery — strong expertise with Tailwind CSS and/or CSS-in-JS solutions. You can implement pixel-perfect designs while maintaining responsive layouts and dark mode support Write well-structured, testable code with thoughtful component abstractions and clean APIs. You know when to abstract and when to keep it simple Strong problem-solving skills and genuine curiosity — you don’t wait for designs to be perfect but proactively identify UX issues and propose solutions. You’re never satisfied with “good enough” and constantly refine your craft Experience with AI coding assistants (OpenAI Codex, Claude, etc.) and eagerness to push the boundaries of AI-assisted development. Part of this role involves creating AI agents to automate portions of the frontend workflow Familiarity with observability and monitoring tools like Datadog, Sentry, or similar platforms for tracking frontend performance and errors in production Upper-Intermediate or better English skills for technical communication, documentation, and collaborating with distributed teams Present your work effectively both verbally and visually — you can articulate design decisions, create component documentation, and explain technical trade-offs clearly Be a Plus: Experience with React Flow, Highcharts, or other complex data visualization libraries Understanding of Node.js/Python/backend fundamentals — you can read backend code and contribute to API design discussions Experience with SWR, React Query, or similar data fetching libraries Hands-on experience with vector search UIs, RAG interfaces, or semantic search implementations Familiarity with MCP (Model Context Protocol), DSPy, or other cutting-edge AI frameworks Experience with monorepo tools (Lerna, Turborepo, Nx) and managing shared component libraries AWS services knowledge (S3, CloudFront, Lambda) and understanding of serverless architectures Built or contributed to design systems or open-source component libraries Experience with Playwright, Puppeteer, or Cypress for comprehensive E2E testing Experience building AI agent interfaces or agentic AI workflows What Shelf Offers: B2B contract Company Stock Options Hardware: MacBook Pro Modern technical stack. Develop open-source software Premier AI development environment: GitHub Copilot, Claude Code, OpenAI Codex, TypingMind, v0, MCP Servers, plus credits for experimenting with emerging AI tools Why Shelf GenAI will be at least a $18 Trillion market by 2032 and Shelf is a core infrastructure that enables GenAI to be deployed at scale We are blazing the path for the future of Artificial Intelligence globally. Our Leadership Team has deep AI domain expertise and enterprise SaaS background to execute this plan We love our customers and our customers love us. Ask a Shelf customer why, and they’ll tell you it’s because of our innovative capabilities, rock-solid reliability, they truly enjoy working with our people, but most of all — it’s the improvements they see in their business KPIs. We have raised over $60 million in funding and our investors include; Insight Partners, Tiger Global, Base10, and others We have high velocity growth powered by the most innovative product in our category We now have over 100 employees in multiple U.S. states and European countries, and we have ambitious hiring goals over the next few quarters.
Technology
Shelf
Senior Frontend React Developer
Senior
Hybrid
Warsaw, Poland
5,000 - 8,500 USD
🏢 Summary: Frontend Engineer role focused on building production-grade Next.js SSR applications that power enterprise AI interfaces with real-time LLM streaming, complex state management, and high-load performance. The position involves architecting scalable, accessible, and secure UIs integrated with AI systems and large-scale data services. It requires delivering performant, enterprise-ready frontend solutions for mission-critical AI-driven workflows. 🗂️ Requirements: 5+ years frontend engineering experience, 3+ years commercial experience with React, Production experience with Next.js SSR applications, Advanced TypeScript expertise, Experience with complex state management in large-scale applications, Experience building AI/LLM interfaces with real-time streaming, Proven performance optimization for high-load applications, Experience with enterprise features: i18n, accessibility, security compliance, Strong knowledge of modern CSS and responsive design, Experience integrating REST APIs and WebSockets, Experience with observability and frontend monitoring tools, Experience with AI coding assistants 📃 Skills: React, Next.js, TypeScript, JavaScript, SWR, REST, WebSockets, Tailwind, CSS, Storybook, ReactFlow, Highcharts, Playwright, Datadog, Sentry, Elasticsearch, DynamoDB, PostgreSQL, Aurora, SOC2 🏢 Description: As a Frontend Engineer at Shelf, you’ll craft the interfaces that make enterprise AI accessible and trustworthy. While others are building chatbots, we’re solving the harder problem: how do you build UIs that help users confidently navigate AI-powered systems processing millions of documents, while maintaining enterprise-grade reliability? You won’t just build React components — you’ll architect production-ready Next.js applications that handle high-load scenarios with complex states, real-time AI streaming, and multiple layers of enterprise functionality. Every interface decision you make directly impacts how knowledge workers at the biggest companies in the market interact with their most critical information. This is frontend engineering at its most demanding. You’ll tackle challenges like building real-time streaming interfaces for LLM responses, architecting state management for concurrent AI operations across multiple tenants, creating accessible interfaces for complex knowledge graphs with thousands of nodes, and ensuring blazing fast interactions even with petabytes of searchable content. Your components will bridge everything from enterprise authentication systems to cutting-edge AI models, requiring both sophisticated technical skills and sharp product instincts. We obsess over frontend quality because we’re building the trust layer for AI itself. When your interfaces gracefully handle edge cases, provide clear feedback during AI processing, and remain performant under load, you’re not just meeting UX standards — you’re directly enabling users to trust AI-powered answers and make critical business decisions with confidence. You’ll work on production SSR applications serving thousands of enterprise users, implementing localization for global markets, ensuring accessibility compliance, and maintaining security standards that pass SOC 2 audits. Your code will integrate with our Elasticsearch clusters, DynamoDB tables, and Aurora PostgreSQL databases through the largest park of REST APIs, handling real-time websocket updates for AI streaming and collaborative features. We’re a product company that ships fast without compromising on lasting quality. You’ll work alongside proactive, ever-learning engineers who actively use AI coding assistants (OpenAI Codex, Claude Code) to accelerate development. We build custom MCP servers, implement DSPy pipelines for LLM optimization, and experiment with different AI tools for implementation. In our environment, AI isn’t just what we build — it’s how we build. The best engineers we know are drawn to problems that matter. If you’re excited by the challenge of building interfaces that make the AI revolution actually usable and trustworthy for enterprise users, this role offers the rare combination of technical depth, meaningful impact, and the prestige of solving UX patterns that the industry hasn’t figured out yet. Responsibilities Design and implement production-ready Next.js SSR applications with complex state management, handling high-load scenarios and real-time AI interactions at scale Build interfaces for AI-powered features including streaming LLM responses, semantic search across millions of documents, interactive knowledge graphs, intelligent content recommendations, and AI agentic builders Architect component libraries and maintain our design system in Storybook, ensuring reusability, accessibility, and consistent UX patterns across the platform Develop enterprise-grade functionality including multi-language support, accessibility compliance, cross-browser compatibility, and security implementations that meet SOC 2 standards Create comprehensive technical specifications and component API designs that clearly communicate interface decisions, performance trade-offs, and accessibility considerations Build and optimize data-heavy UIs using React Flow for node-based graphs, Highcharts for analytics visualizations, and custom virtualization for handling large datasets Instrument components for performance monitoring, track Core Web Vitals, implement error boundaries, and build automated visual regression tests with Playwright Take full ownership of the features you build, monitoring their performance in production, optimizing bundle sizes, and ensuring they scale gracefully as user load grows Work with SWR for intelligent data fetching, caching, and revalidation strategies that minimize API calls while keeping UIs responsive and data fresh Integrate with backend services via REST APIs, handle websocket connections for real-time updates, and implement optimistic UI patterns for seamless user experiences Leverage AI coding assistants to accelerate development while maintaining high code quality, and contribute to building internal AI agents that automate frontend workflows Stay current with React ecosystem best practices, Next.js updates, AI UX patterns, and modern frontend architecture—experiment with new approaches and share findings with the team Contribute to our engineering standards and practices through thoughtful code reviews, mentor colleagues on frontend best practices, and actively participate in our culture of continuous learning Requirements Over 5 years of professional frontend engineering experience, including more than 3 years specializing in React and modern JavaScript/TypeScript Production Next.js experience — you’ve built and shipped SSR applications at scale, understand app router patterns, server components, and the trade-offs between SSR, SSG, and CSR Deep TypeScript expertise — you write type-safe code with generics, utility types, and advanced patterns. Complex state management — hands-on experience architecting state solutions for challenging scenarios: real-time collaboration, optimistic updates, multi-tenant data isolation, and large-scale data synchronization Enterprise application development — you’ve built applications with localization (i18n), accessibility, security best practices, and compliance requirements. You understand the complexity beyond “making it work” AI/LLM interface experience — you’ve built interfaces for AI-powered features: streaming token responses, chat UIs, semantic search, or similar real-time AI interactions High-load optimization — proven track record optimizing applications for performance under heavy traffic, large datasets, and concurrent operations. You monitor Core Web Vitals and know how to improve them Modern CSS mastery — strong expertise with Tailwind CSS and/or CSS-in-JS solutions. You can implement pixel-perfect designs while maintaining responsive layouts and dark mode support Write well-structured, testable code with thoughtful component abstractions and clean APIs. You know when to abstract and when to keep it simple Strong problem-solving skills and genuine curiosity — you don’t wait for designs to be perfect but proactively identify UX issues and propose solutions. You’re never satisfied with “good enough” and constantly refine your craft Experience with AI coding assistants (OpenAI Codex, Claude, etc.) and eagerness to push the boundaries of AI-assisted development. Part of this role involves creating AI agents to automate portions of the frontend workflow Familiarity with observability and monitoring tools like Datadog, Sentry, or similar platforms for tracking frontend performance and errors in production Upper-Intermediate or better English skills for technical communication, documentation, and collaborating with distributed teams Present your work effectively both verbally and visually — you can articulate design decisions, create component documentation, and explain technical trade-offs clearly Be a Plus: Experience with React Flow, Highcharts, or other complex data visualization libraries Understanding of Node.js/Python/backend fundamentals — you can read backend code and contribute to API design discussions Experience with SWR, React Query, or similar data fetching libraries Hands-on experience with vector search UIs, RAG interfaces, or semantic search implementations Familiarity with MCP (Model Context Protocol), DSPy, or other cutting-edge AI frameworks Experience with monorepo tools (Lerna, Turborepo, Nx) and managing shared component libraries AWS services knowledge (S3, CloudFront, Lambda) and understanding of serverless architectures Built or contributed to design systems or open-source component libraries Experience with Playwright, Puppeteer, or Cypress for comprehensive E2E testing Experience building AI agent interfaces or agentic AI workflows What Shelf Offers: B2B contract Company Stock Options Hardware: MacBook Pro Modern technical stack. Develop open-source software Premier AI development environment: GitHub Copilot, Claude Code, OpenAI Codex, TypingMind, v0, MCP Servers, plus credits for experimenting with emerging AI tools Why Shelf GenAI will be at least a $18 Trillion market by 2032 and Shelf is a core infrastructure that enables GenAI to be deployed at scale We are blazing the path for the future of Artificial Intelligence globally. Our Leadership Team has deep AI domain expertise and enterprise SaaS background to execute this plan We love our customers and our customers love us. Ask a Shelf customer why, and they’ll tell you it’s because of our innovative capabilities, rock-solid reliability, they truly enjoy working with our people, but most of all — it’s the improvements they see in their business KPIs. We have raised over $60 million in funding and our investors include; Insight Partners, Tiger Global, Base10, and others We have high velocity growth powered by the most innovative product in our category We now have over 100 employees in multiple U.S. states and European countries, and we have ambitious hiring goals over the next few quarters.
Technology

xAI
Member of Technical Staff – Web Engineering
Senior
On-site
Palo Alto, CA
🏢 Summary: Fullstack/Web Engineer role focused on building and optimizing high-performance, real-time user-facing features for a large-scale social platform. The position emphasizes frontend excellence while contributing across the stack, including scalable backend systems and real-time analytics. You will own features end-to-end, driving architecture, performance, and reliability for globally deployed products. 🗂️ Requirements: 2+ years web development experience, Expertise in TypeScript, Expertise in Node.js, Expertise in React or modern web frameworks, Expertise in CSS/SASS, Experience with UI/UX design, Experience optimizing performance and security, Experience building scalable, high-concurrency systems, Backend development experience, Proficiency in Rust, Go, Java, Python, or Scala 📃 Skills: TypeScript, Node.js, React, CSS, SASS, Rust, Go, Java, Python, Scala, HTML, WebSockets, REST, GraphQL, SQL, NoSQL, Testing, CI/CD, Monitoring, Security 🏢 Description: About xAI xAI's mission is to create AI systems that can accurately understand the universe and aid humanity in its pursuit of knowledge. Our team is small, highly motivated, and focused on engineering excellence. This organization is for individuals who appreciate challenging themselves and thrive on curiosity. We operate with a flat organizational structure. All employees are expected to be hands-on and to contribute directly to the company's mission. Leadership is given to those who show initiative and consistently deliver excellence. Work ethic and strong prioritization skills are important. All employees are expected to have strong communication skills. They should be able to concisely and accurately share knowledge with their teammates.About the Role: We're looking for exceptional Fullstack / Web Engineers that can work across the stack but have a passion for frontend development and a keen eye for design. You'll architect and optimize user-facing features that power real-time conversations for millions worldwide. Dive into cutting-edge technologies and scalable backend systems, collaborating with top-tier talent to push the boundaries of web performance and innovation. You have the ability to thrive in a fast-paced environment, where you proactively tackle high-impact challenges that shape the future of social media—perfect for engineers passionate about crafting seamless, responsive experiences that drive global engagement and redefine digital interaction. Responsibilities: Own and drive features from inception and design to implementation and launch, being the web expert on your team. Build and maintain high-quality, performant products and features, leveraging the most modern and cutting edge web standards, technologies, frameworks, and AI tooling. Responsible for fullstack features, including user dashboards, personalized experiences, content delivery, interactive tools, assessments, and real-time analytics Lead architecture, scalability, and reliability decisions for high-concurrency, low-latency systems. Uphold engineering excellence via testing, monitoring, deployment, and secure data handling. Drive technical/product decisions with teams and deploy global features to maximize user value. Basic Qualifications: 2+ years of web development experience. Expert in TypeScript, Node.js, and modern web frameworks (e.g., React). Expert in modern CSS/SASS Experience in high-quality UI and UX design Proven track record of optimizing applications for performance, security, and offline functionality. Preferred Skills and Experience: 5+ years of experience in a web frontend role, working on a large scale consumer app. Experience with backend development, proficiency in one or more of the following: Rust, Go, Java, Python, Scala. Compensation and Benefits: $180,000 - $440,000 USD Base salary is just one part of our total rewards package at xAI, which also includes equity, comprehensive medical, vision, and dental coverage, access to a 401(k) retirement plan, short & long-term disability insurance, life insurance, and various other discounts and perks.xAI is an equal opportunity employer. For details on data processing, view our Recruitment Privacy Notice.
Technology
Blazity Sp. z o.o.
Senior AI Fullstack Engineer (Next.js & LLM)
Senior
Remote
Warsaw, Poland
120 - 180 PLN/hr
🏢 Summary: The offer is for a Senior AI Fullstack Engineer to design and deliver production-ready, LLM-powered web applications using modern React and Next.js architecture. The role focuses on building autonomous agents, RAG systems, and AI-driven workflows integrated with enterprise-grade products. It involves end-to-end ownership of scalable AI solutions from architecture to deployment. 🗂️ Requirements: 8+ years experience as consultant or forward deployed engineer, Strong experience with Next.js (App Router), React, TypeScript, Deep understanding of Server and Client Components (RSC), Experience with streaming, caching, revalidation, Server Actions, Experience with Vercel AI SDK, LangGraph or MCP, Experience building RAG systems, Hands-on experience with Anthropic and OpenAI APIs, Experience shipping LLM-powered features to production, Practical experience with prompt engineering and structured outputs, Experience with tool calling and agent workflows, Experience with multi-turn orchestration, Understanding of token economics and context windows, Experience with prompt evaluation methods, Ability to design robust, production-ready AI systems 📃 Skills: Next.js, React, TypeScript, RSC, Vercel, LangGraph, MCP, RAG, Claude, OpenAI, Anthropic, Prompting, Streaming, ServerActions, Agents, APIs 🏢 Description: About the Role At Blazity, we are a team of React.js and Next.js experts building modern, API-first digital products for enterprise clients. We are expanding our AI capabilities—autonomous agents, AI-driven automation, and LLM-powered workflows—and are looking for a Senior AI Fullstack Engineer who can design and ship production-ready AI systems. You will work at the intersection of modern web architecture and generative AI , taking ownership of solutions delivered to real users. Our requirements Must-have Technical Excellence: 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 Vercel AI SDK / LangGraph / MCP Experience building RAG systems Claude extended thinking / prompt caching / Batch APIs AI Engineering: Proven experience shipping LLM-powered features to production Hands-on with Anthropic / 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 Reliability & Quality: Experience with: prompt evaluations (LLM-as-judge, rule-based) handling hallucinations and failure modes Ability to design robust AI systems , not just prototypes Soft Skills: Strong ownership mindset Experience working directly with clients Clear communication and structured thinking (English C1) Ability to make decisions in ambiguous environments Nice-to-have: What You Will Do Ship Production Apps: Build scalable web applications using Next.js (App Router) and TypeScript , ensuring high performance and clean architecture. Engineer AI Workflows: Develop and orchestrate LLM-powered features using Anthropic and OpenAI APIs, focusing on tool use and streaming. Agentic Orchestration: Design autonomous agent loops and multi-turn workflows, knowing when to use a structured pipeline versus a dynamic agent. Optimize & Evaluate: Manage token economics (pricing, context windows) and implement prompt evaluations (LLM-as-judge, rule-based) to ensure system reliability. Collaborate: Work directly with senior engineers, founders, and client teams to shape AI capabilities from concept to production. What we offer B2B: 120 – 180 PLN/h + VAT 🔥 100% remote (Poland) 29 paid vacation days Private healthcare + sports card High-impact work on real AI systems