Compare epsilon-greedy, UCB1, and Thompson sampling in a reproducible Bernoulli bandit simulation with reward, pseudo-regret, and repeated-run uncertainty.
Simulate and Compare Multi-Armed Bandit Strategies
Company: Wayfair
Role: Applied Scientist
Category: Machine Learning
Difficulty: medium
Interview Round: Onsite
Build a small simulation that compares common multi-armed bandit strategies. Explain each strategy, record reward and regret, and use the experiment to discuss exploration versus exploitation.
### Constraints & Assumptions
The source reports a bandit simulation exercise with AI and search tools allowed, but gives no arm distributions, horizon, or required output. For this practice discussion, use stationary independent Bernoulli arms with known probabilities available only to the simulator. Compare epsilon-greedy, UCB1, and Thompson sampling over repeated random seeds. This is an experimental simulation exercise rather than a fixed-output console task.
### Clarifying Questions
Are rewards binary or continuous? Is the environment stationary? What is the horizon? Does the policy observe only the chosen arm's reward? How should reproducibility and uncertainty be reported?
### What a Strong Answer Covers
Separate policy knowledge from simulator knowledge, implement each update correctly, distinguish realized reward from expected pseudo-regret, and compare repeated runs rather than a single lucky trajectory. Explain any generated code before relying on it.
### Follow-up Questions
How do the results change with a small reward gap, a short horizon, nonstationary rewards, or a poorly chosen exploration rate? Why is sharing a seed alone insufficient to guarantee identical random consumption across policies?
Overview: Compare epsilon-greedy, UCB1, and Thompson sampling in a reproducible Bernoulli bandit simulation with reward, pseudo-regret, and repeated-run uncertainty.
Simulate and Compare Multi-Armed Bandit Strategies
Wayfair
Sep 10, 2026
mediumApplied ScientistOnsiteMachine Learning
0
0
Build a small simulation that compares common multi-armed bandit strategies. Explain each strategy, record reward and regret, and use the experiment to discuss exploration versus exploitation.
Constraints & Assumptions
The source reports a bandit simulation exercise with AI and search tools allowed, but gives no arm distributions, horizon, or required output. For this practice discussion, use stationary independent Bernoulli arms with known probabilities available only to the simulator. Compare epsilon-greedy, UCB1, and Thompson sampling over repeated random seeds. This is an experimental simulation exercise rather than a fixed-output console task.
Clarifying Questions Guidance
Are rewards binary or continuous? Is the environment stationary? What is the horizon? Does the policy observe only the chosen arm's reward? How should reproducibility and uncertainty be reported?
What a Strong Answer Covers Guidance
Separate policy knowledge from simulator knowledge, implement each update correctly, distinguish realized reward from expected pseudo-regret, and compare repeated runs rather than a single lucky trajectory. Explain any generated code before relying on it.
Follow-up Questions Guidance
How do the results change with a small reward gap, a short horizon, nonstationary rewards, or a poorly chosen exploration rate? Why is sharing a seed alone insufficient to guarantee identical random consumption across policies?