PhD Research Scientist Intern - Reinforcement Learning, Images

Company Overview

Our global headquarters is in Sydney, Australia, and our London campus is located in Hoxton Square, in the middle of Shoreditch. It’s a space where the UK team comes together to connect, create, and collaborate.

Fun fact: the London team is one of the places where the AI powering Canva gets built.

Role Overview

This role is based in London. We’re looking for someone who calls it home. Our hybrid way of working offers flexibility, with the option to work from home and to connect with your team in person on campus. We trust teams to choose the balance that helps them achieve their goals.

Join the team redefining how the world experiences design.

We’re looking for current PhD students ready to bring their research into the real world and help shape the culture of AI at Canva.

AI Research Internship (Full-time, 16 weeks) — starts in September. During your internship, you’ll work directly with Canva’s AI team on a live, industry-scale project, turning part of your PhD journey into real-world impact.

You’ll gain hands-on experience with real data, production infrastructure, and real deadlines, while learning from and working alongside researchers and engineers creating Canva’s next generation of AI-powered experiences.

What You’ll Be Doing

As Canva scales, change is part of our DNA—this role will likely evolve over time. At the moment, the internship focuses on:

• Designing and validating a rubric-guided, per-layer VLM judge for RGBA layer decomposition, calibrated against human evaluations.
• Building VLM-based methods for automatic, human-aligned evaluation of multi-layer designs.
• Turning VLM-based evaluators into reward functions to train generative models in a reinforcement learning setting.
• Distilling those judges into lightweight reward models that score layered images from learned representations, at a fraction of the inference cost.
• Collaborating with research, engineering, and product teams to move findings toward production and Canva’s layered-generation roadmap.
• Contributing to the broader research community through publication where results support it.

The team builds the groundwork before you arrive—baselines reproduced, harnesses running, and data prepared—so you can focus on the novel parts from week one rather than spending a month on setup.

What You’re a Match If

• You’re currently completing a PhD, ideally third year or later.
• You have a strong diffusion or flow-matching background, with hands-on policy-gradient RL for generative models (GRPO, PPO, DPO, or similar).
• You have experience fine-tuning VLMs (e.g., with LoRA) and designing prompts or rubrics for evaluation tasks.
• You have reward modelling experience, preference optimisation, pseudo-labelling, or distillation.
• You can read a recent paper and reproduce it quickly.
• You communicate technical work clearly, in writing and in presentations.
• You enjoy working closely with researchers and engineers on hard problems.
• You can juggle several threads at once, drop into new work without losing context, and set your own priorities daily between checkpoints.

Nice to Have

• PyTorch at scale, and the ability to write research code for data processing, training, and evaluation.
• Multi-GPU training (FSDP, DeepSpeed) and evaluation-harness engineering.
• Experience with layered or RGBA generation, matting, or inpainting.
• Familiarity with reward-hacking and score-compression diagnostics, or human-evaluation design.
• Publications or open-source contributions in generative modelling, RLHF, or multimodal models.

What You Should Aim to Take Away

• Publishable and patentable contributions based on the work you complete.
• A paper draft covering the work, with support on publication strategy.
• Compute, base checkpoints, preference data, and an annotation budget (provided).
• Four mentors: a coach for weekly 1:1s, plus a specialist lead on each workstream.
• Work that feeds directly into a product used by hundreds of millions of people.

Additional Information

We make hiring decisions based on your experience, skills, and passion, as well as how you can enhance Canva and our culture. When you apply, please tell us the pronouns you use and any reasonable adjustments you may need during the interview process.

We celebrate all types of skills and backgrounds at Canva. Even if you don’t feel like your skills fully match everything listed above, we still want to hear from you.

Please note that interviews are conducted virtually.