Freelance Unity Game Developer Jobs in Toronto, ON

We believe AI will fundamentally change how games are built and played, from content creation to player experience, and we're building at the frontier of that shift.

Puzzle Cats builds casual mobile games played by tens of millions of people worldwide. We're a small, high-performing team that moves faster than most studios think is possible, taking games from concept to App Store quickly and continuously iterating on live games with millions of active players.

We're looking for an AI Product Engineer who wants to build something big and move fast. This is a hands-on, highly product-oriented role for someone who wants to invent, ship, and scale AI-native game experiences. You'll work across the full development process, from prototype to production, collaborating with designers, engineers, and product teams to launch new games and improve live ones. Features you build can reach millions of players within weeks.

We're especially interested in engineers who don't just tolerate AI tools, they live inside them. Someone who naturally uses tools like Claude, Cursor, OpenAI, or coding agents as part of how they build, understands the code they generate, and knows when to prompt a solution versus writing it from scratch.

You'll own features end-to-end, from gameplay systems and backend infrastructure to analytics, building, shipping, measuring, and iterating quickly based on real player data. We ship fast, test aggressively, and aren't afraid to kill ideas - including AI ones - if the data doesn't support them.

• Use AI to create new player experiences that wouldn't be possible otherwise
  
• Build and ship mobile game features in Unity (C#) for iOS and Android, including gameplay mechanics, onboarding flows, monetization experiments, and live-ops systems
  
• Prototype and launch new game ideas quickly, moving from concept to playable builds in weeks, not months
  
• Design and build AI-powered gameplay and product features, including content generation, personalization, and AI-driven mechanics
  
• Design and implement AI systems and pipelines, including RAG, embeddings, tool use, and agents
  
• Optimize AI systems for cost, latency, and scalability, including token usage, caching, and model selection
  
• Develop and maintain backend systems for live games, including leaderboards, events, A/B testing infrastructure, and cloud services (GCP/Firebase)
  
• Collaborate closely with designers and analysts to interpret player data and turn insights into gameplay improvements
  
• Own the full lifecycle of your features, including implementation, analytics instrumentation, debugging, and performance optimization
  
• Review code and maintain high engineering standards, including AI-generated code
  

• Strong problem-solving ability, a hacker mindset, and deep object-oriented programming knowledge
  
• Ability to write clean, maintainable code and move quickly without sacrificing quality
  
• Experience integrating real AI features into products, not just using AI tools, but shipping or meaningfully prototyping model-driven functionality
  
• Experience integrating LLMs into production systems using OpenAI, Anthropic, or open-source models
  
• Strong intuition for how LLMs behave, including prompt design, failure modes, and output quality
  
• Experience building and iterating on AI features using real user data
  
• 3+ years of production software engineering experience, ideally with shipped mobile apps or games built in Unity (C#) for iOS and Android
  
• Experience with Python or JavaScript, cloud infrastructure/back-end systems, and Git
  
• Ability to analyze player data and metrics to improve gameplay and product decisions
  
• Strong critical thinking, communication skills, and empathy for players
  
• Comfort working in ambiguity and figuring things out without playbooks
  
• Ability to go from idea to prototype to production in days or weeks, not months
  

• Experience applying AI to gameplay systems, including procedural content generation or LLM-driven systems such as personalization, dialogue, level generation, or dynamic difficulty
  
• Experience designing AI pipelines such as RAG, embeddings/vector search, and tool use/function calling
  
• Experience fine-tuning or working with open-source models
  
• Game design sensibility and a strong feel for what makes mechanics engaging
  
• Experience with Python scripting for tooling, automation, or data pipelines
  
• Experience optimizing Unity mobile performance, including memory profiling, draw call optimization, and frame-rate debugging
  
• Experience shipping multiple mobile game titles
  

• Days 1-7: Ship your first feature or fix to a live game and get familiar with the full stack
  
• Days 7-14: Contribute to a new game prototype and help improve a product metric
• Days 14-30: Operate independently and ship at least one improvement that wasn't originally on the roadmap