Senior Full-Stack Developer | GenAI LLM experience | Typescript, React, Next.js, Node.js, Nest.js

About the Position

We are seeking a Senior Full-Stack Developer with expertise in GenAI and LLM, using Typescript, React, Next.js, Node.js, and Nest.js for a remote position in Zagreb, Croatia.

Responsibilities

• Design and develop scalable backend services
• Write clean, maintainable code
• Collaborate with frontend team
• Implement complex front-end and full-stack features end to end
• Own API design and data modelling
• Create polished, performant UIs

Requirements

• 5+ years of experience as a full-stack JavaScript/TypeScript developer
• Proficiency in Typescript, React, Next.js, Node.js, and NestJS
• Experience with Vue.js, GraphQL, Docker, AWS, Full Stack Development, Front End Software Development, API Design, Tailwind CSS, JavaScript, Python, PostgreSQL, MongoDB, OAuth, Prism, E2e Testing, Mocha, FastAPI, Chatbots, Generative AI, Databricks, Jest, Playwright, Cypress, Cucumber, WebSockets
• Comfortable working in distributed, agile teams
• Strong experience with React, Zustand, GraphQL, Playwright, Emotion, Next.js, SWR, Tailwind, Shadcn, AI Elements, Tiptap, Lexical, Yjs, WebSockets, Casbin, Cypress, Cucumber, D3.js, DeckGL, Chart.js, and React (TanStack) Table

Nice to Have

• Experience with Vue3, Vuex, Vuetify, Angular, Redux
• Knowledge of AWS services like Lambda and DynamoDB using the Infrastructure as Code approach (IaC) and the AWS CDK

We Offer

• 100% remote work from Zagreb, Croatia
• Opportunity to work on cutting-edge projects in GenAI/LLM applications, complex front-ends, and data/analytics platforms
• Collaborate with top-tier clients such as Databricks, BCGX, NATO, VW, Audi, DHL, and TeamViewer

About the Company

I’m a senior full‑stack JavaScript/TypeScript developer with a front‑end focus and 7+ years of experience delivering production web applications for enterprise clients. I work primarily as a remote B2B contractor and have contributed thousands of hours to organisations such as Databricks, BCG/BCGX, NATO, VW, Audi, DHL, and TeamViewer, across domains including GenAI & LLM products, data analytics, automotive, logistics, EdTech, industrial processing, and forestry.

My core stack: TypeScript, JavaScript, React, Next.js, Node.js, NestJS, Vue.js, with tools like Zustand, Redux, GraphQL, REST, Tailwind CSS, Emotion, SWR, Jest, Playwright, Cypress, Cucumber, WebSockets, AWS (Lambda, DynamoDB) and Docker.

I’m comfortable owning complex front‑end and full‑stack features end to end, from API design and data modelling to polished, performant UIs.

Recent highlights include:

• GenAI Chatbot for NATO – senior front‑end developer on an LLM/RAG‑powered assistant for engineers and researchers, using Next.js 14+ (App Router), SWR, Tailwind and AI Elements.
• MLflow at Databricks – senior front‑end developer work on an enterprise data analytics and ML/GenAI observability platform with React, Zustand, GraphQL, Playwright and Emotion.
• GenAI writing platform for BCGX – senior full‑stack role on a greenfield Next.js 14+ (App Router) app with a collaborative WYSIWYG editor (Tiptap, Lexical, Yjs, WebSockets), RBAC/ABAC permissions (Casbin) and E2E tests (Cypress, Cucumber).
• Value Chain Analytics platform for BCG Gamma - senior front-end role on an advanced multi-page React dashboard with complex data visualisations (charts, geo maps, tables, Sankey diagrams) using D3.js, DeckGL, Chart.js, and React (TanStack) Table.

I’m experienced in distributed, agile teams, working closely with product, design and data stakeholders, and I tend to operate as a senior IC who can independently drive features from idea to release.