Senior Full-Stack AI Engineer | Node/React, On-Site Warsaw

Epcnetwork; Warszawa; On-site; PLN 180,000 - 280,000; Full time

Benefits offered by this job

Bonuses according to policy

Cozy office in Warsaw

Snacks & beverages

Job summary

EPC Network is seeking a Senior FullStack Developer to own AI-powered internal products and automation platforms from UI to backend, including LLM integrations and production reliability. Work closely with AI, product, and marketing teams, reporting to the Lead of AI.

You will design and implement scalable front-end and back-end solutions, build integrations with external APIs, and configure n8n workflows for social media publishing.

Qualifications

• 4+ years of commercial software development experience, primarily in full-stack or backend-heavy roles.
• 1+ year hands-on experience building AI/LLM-powered applications or features.
• Strong practical experience with REST APIs, webhooks, and third-party integrations.

Responsibilities

• Design, develop, and maintain scalable front-end and back-end solutions for internal platforms, automation workflows, and third-party integrations.
• Build and maintain reliable integrations with external APIs and services, including authentication, webhooks, retries, rate limits, and error handling.
• Design and configure n8n workflows for automated social media publishing across LinkedIn, X, Threads, and Instagram, including UTM tracking and related automation.
• Build and maintain asynchronous processing using BullMQ — queues, workers, schedulers, retries, and failure handling.
• Ensure production reliability through structured logging, monitoring, metrics, alerting, and effective troubleshooting.
• Write and maintain unit, integration, and end-to-end tests to ensure code quality and system stability.
• Participate in code reviews, contribute to architectural decisions, and continuously improve engineering practices.
• Take ownership of features end-to-end — from technical design and implementation to deployment, monitoring, and production support.

Skills

Full-Stack Development

AI/LLM Experience

REST APIs

Asynchronous Workflows

PostgreSQL

Redis

Docker

CI/CD

Security & Auth

Code Reviews/Architecture

English Communication

Tools

BullMQ

n8n

LLM APIs

React/Frontend

FastAPI/Node.js

Job description

EPC Network is seeking a Senior FullStack Developer to own AI-powered internal products and automation platforms from UI to backend, including LLM integrations and production reliability. Work closely with AI, product, and marketing teams, reporting to the Lead of AI.

You will design and implement scalable front-end and back-end solutions, build integrations with external APIs, and configure n8n workflows for social media publishing.