Software Engineer Intern (Europe)

About DeepInfra

DeepInfra is building the infrastructure layer for the next generation of AI. We believe open-source models are the future, and companies should have full control over their AI stack without being locked into proprietary providers.

Our inference platform serves trillions of tokens every week across hundreds of production workloads. We build everything from GPU infrastructure to the API layer because every millisecond matters.

We’re looking for a Software Engineering Intern to join our engineering team in Sofia.

Why this role matters

You’ll work side by side with our engineers to design, build, and deploy leading open-source AI models at scale. Your code goes into the systems that serve these models, so you’ll learn what it takes to make software fast, efficient, and reliable when every millisecond counts. If you want real engineering work instead of a sandbox project, apply.

What You’ll Do

• Collaborate with the engineering team to design, develop, and test inference solutions for the top AI models.
• Implement and optimize AI models using Python, C++, CUDA, NCCL
• Monitor and maintain the live service.
• Work on feature development, bug fixing, and code reviews to ensure high-quality software delivery
• Participate in daily stand-ups, code reviews, and design discussions to ensure seamless collaboration
• Stay up-to-date with industry trends and advancements in AI and machine learning
• Try new things
• Ship stuff

What You Bring

• Currently pursuing a Bachelor's or Master's degree in Computer Science, Computer Engineering, or a related field
• Strong fundamental knowledge in computer science, including data structures, algorithms, and software design patterns
• Proficiency in Python, including experience with AI/ML libraries and frameworks (e.g., NumPy, pandas, SciPy, TensorFlow, PyTorch)
• Familiarity with AI models, Transformers and Diffusers
• Experience with version control systems (e.g., Git) and agile development methodologies
• Excellent problem-solving skills, with the ability to debug and optimize code
• Strong communication and teamwork skills, with the ability to effectively collaborate with cross-functional teams

Why DeepInfra

• Work on cutting-edge AI model serving - the systems that power the next generation of LLMs and multimodal models.
• Small team, huge impact: your work ships directly to customers.
• Opportunity to learn from engineers building high-performance inference at scale.
• Fast-paced environment with ownership, autonomy, and end-to-end responsibility.

How we workThree traits define the people who thrive here, and this role leans on all three.Initiative. We take ownership and step in where we can add value. Whether it’s starting something new, improving what exists, or helping move ideas forward, we aim to be proactive and thoughtful in how we contribute.

Drive. We’re energized by hard problems. Building AI infrastructure is complex, and we lean into that. We care about doing things well, moving fast, and continuously improving because solving meaningful challenges is what motivates us.

Grit. Things don’t always work on the first try and that’s expected. We stay persistent, adapt quickly, and learn as we go. We take setbacks seriously, but not personally, and use them to get better.