09/23/2026 updated
Premium member
100 % availableSenior Full-Stack Developer | GenAI LLM experience | Typescript, React, Next.js, Node.js, Nest.js
Zagreb, Croatia
Only remote
Master of Science in Electrical Engineering and TechnologyAbout me
Senior JS/TS full‑stack developer (front‑end focused) with 7+ years as a remote B2B contractor for clients such as Databricks, BCGX and NATO. Experience in LLM chatbots, GenAI writing platforms and data analytics tools for ML/GenAI development, evaluation and observability.
Tailwind CSSHTMLJavaScriptUnit TestingCascading Style Sheets (CSS)GitHubPython (Programming Language)PostgreSQLMongoDBNode.jsOAuthPrism (Software)E2e TestingNext.jsTeamViewer
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.
I work 100% remotely from Zagreb, Croatia and am interested in new freelance B2B contracts, especially around GenAI/LLM applications, complex front‑ends and data/analytics platforms
Experience
Professional experience5 - 10 years
Freelancer since2022
Languages
GermanBasic knowledgeEnglishFluentCroatianNative speaker
Project history
Worked on Mlflow, an enterprise data analytics platform for developing models, generative AI applications, state-of-the-art experiment tracking, observability, and performance evaluation for machine learning models, and agents on the Databricks lakehouse. As a front-end developer I utilised React, Zustand, GraphQL, Playwright, Emotion and other tools.
I worked on a GenAI Chatbot powered by LLMs such as OpenAI GPT models. The Chatbot provides personalised assistance for NATO employees, such as engineers and researchers, by using a proprietary knowledge-base and RAG to enhance the context and quality of responses. As a front-end developer I utilised Next.js, SWR, Tailwind, Shadcn, AI Elements and other tools
- Managed a GenAI writing platform for creating structured documents and automating E2E workflows.
- Developed an intuitive UI in Next.js 14 that enables a user-friendly experience. The core of the UI is a real-time, collaborative WYSIWYG editor where the Writer AI agent can stream LLM-generated content.
- Built collaborative Google Docs style comments using Tiptap and Lexical editors, Yjs as a CRDT sync engine with shared data types to merge conflict-free changes from different users in real time, on top of a WebSocket back end.
- Implemented a full-stack, E2E permissioning system based on a combination of RBAC (role-based) / ABAC (attribute-based) architecture using the Casbin authorization library.
- Set up and implemented various e2e feature tests with Cypress and Cucumber (to support BDD Gherkin syntax).