Applied Machine Learning Scientist (Early Career)

This will be a remote role to start, with plans to transition to hybrid in-office 2x/week located in downtown Toronto.

**Please note: We are unable to provide visa sponsorship at this time.

Why this role at OpenTable?

OpenTable seats 25 million diners each month across 60,000+ restaurants and taps into more than 20 years of booking data—an ideal launchpad for an early‑career ML scientist. In our tight‑knit team, every experiment you run and every model you ship goes live quickly and at scale. You’ll start with well‑scoped projects and close mentorship, then rapidly earn the freedom to pitch and implement research ideas that deliver measurable value for diners, restaurants, and the business. We celebrate agency, speed, and relentless experimentation, balanced by disciplined prioritization rooted in ML expertise and real‑world production and business constraints.

Responsibilities:

• Research & Productionise Prototype, validate, and deploy ML models that power search, ranking, recommendations, pricing, and conversational recommendation systems.
• Data Pipelines Build reliable pipelines in PySpark; ensure reproducibility, lineage, and monitoring.
• Experimentation Design online A/B tests, define success metrics, and analyse results to inform product decisions and areas of further experimentation.
• Tooling & Best Practices Contribute to internal ML libraries for training, evaluation, debugging, and interpretation; champion code quality and reproducibility.
• Research Awareness Stay current with ML/RL literature, and constantly evaluate new models 

Must‑Have Qualifications:

• Education Recently completed BSc, MSc, or PhD in Computer Science, Statistics, Mathematics, or a closely related technical field.
• Technical Skills
  • Hands-on experience training, tuning, and debugging both classical models (e.g., GBDTs) and deep-learning models (primarily Transformers).
  • Python proficiency and fluency with the scientific/ML stack: one of PyTorch / TensorFlow / JAX, core libraries (NumPy, Pandas, scikit‑learn), and at least one gradient‑boosting toolkit (XGBoost, LightGBM, or CatBoost).
  • Strong command of algorithms, data structures, and object‑oriented design.
• Applied ML Expertise
  • Detecting & mitigating target leakage, train‑test temporal skew, data drift, and other common pitfalls in building production models.
  • Translate business objectives into quantifiable ML metrics (e.g., MRR, MAP, precision/recall, AUC, F1, NDCG) and choose appropriate loss functions (e.g., Plackett–Luce, cross‑entropy, focal loss) to optimise them.
• High Agency & Ownership Demonstrated ability to identify opportunities, form hypotheses, and drive projects that align with business objectives with minimal supervision.
• Communication & Collaboration Clear written/verbal communication and a collaborative mindset.

Nice‑to‑Have:

• Reinforcement Learning Hands‑on RL experience—especially fine‑tuning LLMs toward verifiable objectives or applying RL/bandits in recommendation and ranking—is a strong plus.
• Domain Expertise Background in learning‑to‑rank, recommender systems, conversational agents, or NLP.
• Portfolio: Open‑source contributions, Kaggle medals, blogs or peer‑reviewed publications that replicate and extend academic research.
• Production ML Ops Experience with Spark, Airflow, Docker/Kubernetes, feature stores, and model observability/monitoring.

OpenTable strives to provide a fair, collaborative, and balanced work environment.

Benefits and Perks:

• Generous paid vacation + time off for your birthday
• Work from (almost) anywhere for up to 20 days per year
• Focus on mental health and well-being:
  • Company-paid therapy sessions through SpringHealth
  • Company-paid subscription to HeadSpace
  • Company-wide week off a year - the whole team fully recharges (and returns without a pile-up of work!)
• Paid parental leave
• Paid volunteer time
• Focus on your career growth:
  • Development Dollars
  • Leadership development
  • Access to thousands of on-demand e-learnings
• Travel Discounts
• Employee Resource Groups
• Private health and dental insurance
• Life and Disability insurance

There are a variety of factors that go into determining a salary range, including but not limited to external market benchmark data, geographic location, and years of experience sought/required. The range for this Toronto, Canada based role is $120,000-$150,000 CAD.

We offer a competitive base salary and benefits including: health benefits; flexible spending account; retirement benefits; life insurance; paid time off (including PTO, paid sick leave, medical leave, bereavement leave, floating holidays and paid holidays); and parental leave benefits. This role is eligible to be considered for an annual bonus and equity grant.

We’re committed to creating a workplace where everyone feels they belong and can thrive. We know the best ideas come when we bring different voices to the table, so we're building a team as dynamic as the diners and restaurants we serve—and fostering a culture where everyone feels welcome to be themselves.

If you need accommodations during the application or interview process, or on the job, we’re here to support you. Please reach out to your recruiter to request any accommodations.