Summer Software Engineering Intern

Our main product is a payroll and timekeeping app for hourly workforces, sold by subscription and supported from Madrid. Founded in 2014, the business writes the billing, metering and customer portal software that small water and electric utilities run on. We keep recurring meetings to Tuesdays and Thursdays where we can.

About the role

This is a hands-on coding internship. Most of the work is in Python and Node.js, with some SQL and a bit of shell scripting. This role is fully remote within Spain. Normal business hours, Monday to Friday, with some flexibility.

What you'll do

Raise pull requests on GitHub and respond to code review comments within a day. Pair with other engineers over screen share to work through tricky problems. Update the README and internal Confluence pages when you change how something works. Add unit tests with pytest or Jest so new code does not lower coverage. Query and update data in PostgreSQL or MySQL, including simple migrations. Fix bugs from the Jira backlog, starting with small, well-defined tickets. Write and test backend features in Python or Node.js under the guidance of a senior developer.

What we're looking for

Currently enrolled in a bachelor's or master's degree, graduating 2027. Eligible to work in Spain. Based in Spain for the duration of the internship. Available for 30 to 40 hours a week for the full internship period. Own laptop with at least 8 GB RAM and a reliable internet connection. Comfortable writing simple SQL queries (SELECT, JOIN, GROUP BY).

What you get out of it

How a production codebase is organised, deployed and monitored. Writing tests is part of the job here, and you will get good at it.

Duration: 5 months

Start date: Dec 2026

Stipend: €1,100-€1,550 monthly

What we offer

Possibility of a full-time offer. Company laptop. Online learning budget. Flexible hours. Certificate of completion. Internet allowance.

Duration: 5 months. Start: Dec 2026.

Demo job created on 11jobs for testing and demonstrations. It is not an actual opening at Costa Software S.L..