Full-stack Developer (React / Next.js / Python) - Mid/Senior

HIBERUS POLAND SPÓŁKA Z OGRANICZONĄ ODPOWIEDZIALNOŚCIĄ; Warszawa; On-site; PLN 180,000 - 240,000; Full time

Benefits offered by this job

Karta Multisport

Multisport card

Private medical care

Job summary

HIBERUS POLAND SPÓŁKA Z OGRANICZONĄ ODPOWIEDZIALNOŚCIĄ is seeking a skilled Full-Stack Developer to join a modern SaaS product powered by AI, LLMs, and large datasets. You will contribute from frontend to backend, delivering robust features and responsive interfaces.

Requirements include 3+ years in full-stack roles and strong proficiency in TypeScript, React, Next.js, and Python, plus REST API design. The role offers a dynamic, international environment with opportunities to work across borders.

Qualifications

• Minimum 3 years of commercial experience as a Full-Stack Developer.
• Strong knowledge of TypeScript, React, Next.js, and Python.
• Experience designing and integrating REST APIs.
• Knowledge of SQL, relational databases, and ORMs.
• Experience with asynchronous processes and third-party service integrations.
• Ability to build responsive and intuitive user interfaces.
• Familiarity with Git and best practices for code quality and testing.
• Ability to independently own tasks end-to-end, from frontend to backend.
• Self-motivated and proactive in proposing solutions.

Responsibilities

• Developing the web application and new product modules.
• Building responsive and high-performance user interfaces using React and Next.js.
• Developing APIs and backend services in Python.
• Integrating the frontend with the backend, databases, and external APIs.
• Building features powered by LLMs, including response streaming.
• Developing views for presenting data, campaigns, reports, and analytics.
• Optimizing asynchronous processes and data processing workflows.
• Designing and developing APIs based on REST and OpenAPI.
• Ensuring code quality, testing, performance, security, and robust error handling.
• Contributing to the system architecture and participating in technical and product-related decisions.

Skills

TypeScript

React

Next.js

Python

REST APIs

SQL

ORMs

Git

End-to-end ownership

Asynchronous processes

Tools

Docker

Redis

OpenAI Gemini

Vercel

FastAPI/Flask

Job description

About the company

More Than One Project. More Than One Market.

We are part of Hiberus, a technology company founded in Spain with a strong presence in the Polish market: 4,700+ specialists, operating in 14+ countries and delivering projects for clients worldwide.

We work with technologies including AI, Data, Cloud, Software Development, BI, and Cybersecurity. But above all, we put people first. When one project comes to an end, we look for new opportunities within Hiberus — including projects in other countries.

One of our key advantages is Hiberus University — an international learning environment offering real opportunities to develop and expand your skills. More than 1,000 people were trained last year in selected technologies.

Your first project is just the beginning. With Hiberus, you can build a long-term career.

We are looking for a Full-Stack Developer to join a team working on a modern SaaS product powered by AI, LLMs, and large datasets.

Technology stack: Python 3.12, TypeScript, React, Next.js, Flask / Connexion, SQLAlchemy, PostgreSQL, SQL, OpenAI / Google Gemini, REST / OpenAPI

Key Responsibilities:

• Developing the web application and new product modules.
• Building responsive and high-performance user interfaces using React and Next.js.
• Developing APIs and backend services in Python.
• Integrating the frontend with the backend, databases, and external APIs.
• Building features powered by LLMs, including response streaming.
• Developing views for presenting data, campaigns, reports, and analytics.
• Optimizing asynchronous processes and data processing workflows.
• Designing and developing APIs based on REST and OpenAPI.
• Ensuring code quality, testing, performance, security, and robust error handling.
• Contributing to the system architecture and participating in technical and product-related decisions.
• Karta Multisport
• Multisport card
• Private medical care

Experience required

• Minimum 3 years of commercial experience as a Full-Stack Developer.
• Strong knowledge of TypeScript, React, Next.js, and Python.
• Experience designing and integrating REST APIs.
• Knowledge of SQL, relational databases, and ORMs.
• Experience with asynchronous processes and third-party service integrations.
• Ability to build responsive and intuitive user interfaces.
• Familiarity with Git and best practices for code quality and testing.
• Ability to independently own tasks end-to-end, from frontend to backend.
• Self-motivated and proactive in proposing solutions.

Nice to have: Experience with LLMs/GenAI, OpenAI/Gemini, Redis, Docker, FastAPI/Flask, Vercel, and SaaS/martech products.