Backend Intern: Improve the AI Engine That Catches Pay Errors

PayTjek

2000 Copenhagen

Location
2000 Copenhagen
Company
PayTjek
Working hours
Full-time
Posted
14 October 2026
Application deadline
13 November 2026
Category
Softwareudvikler, backend

About the job

Help improve the AI that finds the errors humans miss.

Pay errors are common, yet very few payslips ever get checked. At PayTjek we use AI and machine learning to find those errors in seconds, so trade unions can catch them and set things right for their members. As our backend intern, you will help make that engine even better.

About PayTjek

PayTjek checks payslips and employment contracts against Danish collective agreements. We combine the latest within AI and machine learning with a deterministic rule engine: AI reads documents and extracts the rules from collective agreements, and the rule engine makes sure the result is correct. Not a model that guesses. Our customers are trade unions that use PayTjek to find pay errors for their members and document them so a claim can be raised. The system checks 12 payslips in 90 seconds.

Korrekthed. Ikke sandsynlighed. Correctness, not probability.

We are a young company with big ambitions. Our goal is to make payslip checks a natural part of what every trade union offers its members, first in Denmark and then across Europe. You will work alongside a small team of highly skilled people, with a background in formal verification from DTU, and you will have real influence from day one. Our first full-time developer started with us as an intern.

What you will work on

  • AI and machine learning for document understanding: OCR, rule extraction and turning legal text into rules
  • Connecting the rule engine to our case flow
  • APIs and data models for payslips, contracts and collective agreements
  • Testing and quality assurance of rules

Who you are

  • You know Python
  • Experience with cloud, Docker and containers is a plus
  • You are curious about AI, machine learning and correctness
  • Most important of all: you are eager to learn and not afraid to dive into something new
  • You are able to work from our office in central Copenhagen

What we offer

  • Hands-on work with the newest technology within AI and machine learning
  • Real tasks in a product used by real customers
  • Daily sparring with skilled colleagues, including our CTO and backend developer
  • A real opportunity of employment after the internship, just like our first full-time developer
  • A front row seat in a startup on its way up

This is an unpaid internship.

How to apply: Apply here on The Hub with a short motivation and your CV or GitHub.

Questions? Feel free to call me, Theis Veddinge, Co-founder and CEO, on +45 61 54 19 23.

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Backend Intern: Improve the AI Engine That Catches Pay Errors

PayTjek · 2000 Copenhagen