Intern Backend Engineer (AI) at PayTjek

Want to help revolutionize payroll verification?

PayTjek is an AI-driven startup helping employees ensure they get the salary they’re entitled to — with just one click. Users simply upload their payslip, and our AI automatically checks for errors and discrepancies. We’re tackling a massive problem by automating payroll verification and making salary expertise accessible to everyone.

About the Role

We’re looking for a passionate Backend Engineering Intern with a strong interest in AI to help build and scale our verification platform. You’ll be an integral part of our development team and have real influence over how we design and deliver reliable, intelligent backend services — from concept to production. We don’t expect you to know everything on day one; a strong willingness to learn and grow is what matters most.

You’ll be working on:

• Designing and implementing API endpoints for verification and data ingestion (e.g., payroll analysis, knowledge base, calendar shifts)

• Integrating our OCR engine to parse Danish payslips into structured JSON

• Building and querying our vector knowledge base for overenskomster (e.g., embeddings, Qdrant)

• Orchestrating LLM-based workflows for multi-modal reasoning and discrepancy detection

• Data modeling and persistence for contracts, shifts, and verification results

• Improving performance, reliability, observability, and error handling across services

What We’re Looking For

• Experience or strong interest in backend development and AI-driven systems

• Familiarity with Python (preferred) or TypeScript/Node.js

• Understanding of REST APIs, databases, and asynchronous processing

• Strong problem-solving skills and interest in data pipelines/integrations

• Bonus: experience with vector databases (e.g., Qdrant), embeddings, LLM tooling, OCR, scraping (e.g., Playwright), or calendar/ICS parsing

As a person, you:

• Take ownership of your work

• Are eager to learn and grow

• Are passionate about building robust systems that help real users

• Are comfortable learning new tools and concepts as we go

What You’ll Get

• Be part of shaping PayTjek’s product from early stage toward first launch

• Work directly with real user feedback and real-world data

• Flexible hours and remote work options

• Opportunity for a full-time role after the internship

You’ll be joining us at an exciting stage, helping transform PayTjek from early concept into a product people love. We are pre-MVP and moving quickly toward our first release — there’s plenty of room to strengthen our backend: scaling the Analysis Engine, enhancing OCR parsing, expanding calendar ingestion, and evolving our knowledge base. We move fast, iterating based on real-world feedback from users like nurses and other employees.

We keep things relaxed and collaborative, celebrating small wins together at the end of the week. As we grow and reach more users, we aim to expand from a lean, part-time setup into a full-time team.

We value open communication and an active feedback culture, because learning and improving is part of our DNA. Along the way, you’ll gain practical experience with system design, data processing, AI orchestration, and the impact of technology in the workplace.