Software Developer Intern

Please note that a valid student status in Slovenia is required for this position.

Celtra is looking for a Software Developer Intern who will have an opportunity to work on our products, used by top companies and thousands of people on a daily basis. You will be joining one of our cross-functional teams and, with the support of our mentors, you will get your hands dirty by working on some interesting projects.

Your responsibilities:

• Developing a back-end and front-end of our products that are used by top companies and thousands of people on a daily basis.
• On the back-end you will mainly work on our APIs (REST, web sockets) and family of background jobs.
• On the front-end you will be implementing rich experiences in our apps, participating in revamping the client-side architecture and general redesign of the product frontend.
• Making sure we maintain a high level of quality by writing automated tests.

Qualifications 

• Understanding of RESTful API architecture.
• Knowledge of HTML5 and CSS.
• Knowledge of JavaScript.
• Knowledge of at least 1 backend programming language (Python, PHP, Ruby, Java, Go, Scala …).
• Good verbal and written English communication skills.
• Willingness to constantly learn and improve.
• Team player.
• Active student status in Slovenia.

What brings extra points?

• Knowledge of Vue.js.
• Knowledge of global state management concepts.

If you do not fulfill all the criteria above, but you think you would be a great fit, we encourage you to apply either way!

What we offer?

• Buddy and mentor that will help you grow professionally, plus a well structured development plan. 
• Remote working. You can choose to work from home or join us in our Ljubljana office.
• Flexible hours and work-life balance. We focus on results rather than schedules.
• Top-notch working equipment.
• We have fun. We organise regular team & company events.
• Free breakfasts & beverages available in the office.

About Celtra

Celtra is redefining digital advertising by making it faster, smarter, and more effective. Our software solutions automate creative production, optimize performance with AI-driven insights, and simplify media activation. Marketers can personalize ads at scale, adapt them for any channel, and leverage real-time data to drive better results. Top brands like Spotify, Adidas, Unilever, Hearst, and Bloomberg trust Celtra to boost engagement, streamline workflows, and maximize ad impact.

Empowering Creativity through Diversity & Inclusion

Our mission is to empower creativity - and we cannot fulfill our mission without different perspectives. Diversity drives innovation, and Celtra is committed to diversity, equity, inclusion, and belonging. 

Every employee is empowered at Celtra - no matter your race, age, religion, gender identity, sexual orientation, physical or mental ability, or ethnicity.  We hire the best, and develop our teams through continuous education and mentorship, in a community where everyone can bring their whole selves to work.