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Celtra

Software Developer & ML Researcher Intern- AI & Analytics Team

Celtra
Slovenia · Internship · Not Applicable

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

Ever wonder how Spotify creates ads that look as stunning in English as in Arabic? How Adidas generates beautifully crafted dynamic creatives for tens of thousands of products? Or how Warner Bros shows billions of ads across the globe on mobile phones, websites, and even TV within milliseconds? The software we create here at Celtra makes this as easy as pie, and we need your help!

About The Role

We are seeking a Software Developer & ML Researcher Intern who will work on developing our AI features, designed to streamline creative processes, as well as develop and enhance machine learning models that boost client's ad performance on the Celtra platform. With some prior knowledge of machine learning, this role will primarily focus on implementing and integrating cutting-edge AI models into real-world applications. It involves working with bleeding-edge technologies, fine-tuning models to improve performance, and developing features powered by these models. The role also includes a component of research and staying up to date with the latest advancements in the field.

What Kind of Tech Stack Do We Use?

On the backend, you can find Scala, NodeJS, PHP, MySQL, Spark, Snowflake, and also MongoDB, Kinesis. On the frontend, we use Vue.js, Typescript and Vanilla JS when needed. Everything runs on the AWS cloud, and the ECS cluster orchestrates it. We also love CI/CD, IaC and do daily deployments to ensure your contributions see the light of day as soon as the QA team is happy.

We also actively embrace AI-assisted development with Cursor to boost productivity, iterate on PoCs and explore new ways of building software.

Your Responsibilities As An Intern

  • Model Development: Research, build, and refine machine learning models to help clients optimize creative workflows, automate tasks, and maximize performance within Celtra’s platform.
  • Developing a back-end and front-end of our AI features that are used by top companies and thousands of people on a daily basis.
  • AI Optimization: Continuously optimize AI tools to ensure the best performance, speed, and scalability for clients running global campaigns.
  • Collaborate with Cross-Functional Teams: Work closely with data scientists, engineers, and product managers to integrate AI capabilities into our products and services.
  • Research and Innovation: Stay up-to-date with the latest advancements in AI and machine learning. Evaluate new technologies and methodologies to continuously improve our models and solutions.
  • Code Quality and Documentation: Write clean, maintainable, and well-documented code. Participate in code reviews and contribute to best practices in software development.

You’ll Thrive in This Position if You:

  • Have a genuine interest in AI/ML and exploring new technologies.
  • Enjoy learning, problem-solving, and working on technical challenges.
  • Are proactive, communicative, and love working with a team.
  • Are ready to continuously learn and improve.
  • Possess strong written and spoken English.

What Brings Extra Points (Not Required):

  • Experience using services like Google Gemini, AWS Bedrock, or PyTorch.
  • An interest in vector databases (Pinecone, Chroma, Snowflake) for retrieval augmented generation.
  • TypeScript/JavaScript.
  • SQL.

What Do 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.
  • Regular team & company events.
  • Free breakfasts & beverages available in the office.

About Celtra

Celtra helps enterprise advertisers, media, and agencies design, approve, and deliver digital creative across the ever-growing number of campaigns, markets, designs, and variants. Celtra’s Creative Automation & Enablement Software for helps brands move faster than ever while dramatically scaling content production. Companies like adidas, TripAdvisor, Spotify, Unilever, NBCU, Lululemon, YETI, Vice, and hundreds more partner with Celtra to cut production costs while increasing efficiencies and output in the cloud.

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.

https://www.celtra.com/candidate-privacy-policy/

Key Skills

Ranked by relevance

ai machine learning aws typescript ai tools vanilla scala mysql cloud spark cicd php ecs
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Posted
Jun 19, 2026
Type
Internship
Level
Not Applicable
Location
Ljubljana
Company
Celtra

Industries

Software Development

Categories

Other

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