Bayesian Machine Learning in Python: A/B Testing
by Lazy Programmer Inc. · Udemy
Our Verdict
Worth it — with caveatsLazy Programmer Inc.'s "Bayesian Machine Learning in Python: A/B Testing" is a focused, code-along Udemy course that is worth taking if you specifically want to understand the explore-exploit problem and multi-armed bandit algorithms, but it is narrower than its catalog blurb suggests. Across roughly 10.5-13 hours of video it walks from frequentist A/B testing (confidence intervals, hypothesis tests, z-tests, p-values) into adaptive and Bayesian methods (epsilon-greedy, optimistic initial values, UCB1, and Thompson sampling with Bernoulli and Gaussian rewards). It holds a real 4.3 out of 5 from about 7,982 ratings with roughly 46,400 students enrolled (Class Central / Udemy data), and the most common praise is its clear organization and presentation while the most common criticism is that the math is paced too fast and the coding portion is thinner than in other Udemy ML courses. Despite the description mentioning "Bayesian neural networks," the verified syllabus on the instructor's own site does not cover neural networks; the real scope is A/B testing and bandits, so set expectations accordingly.
Strong, well-reviewed (4.3/5, ~7,982 ratings) for its actual niche -- Bayesian/adaptive A/B testing and multi-armed bandits -- but it assumes comfort with calculus, probability, Bayes rule, and NumPy/SciPy, and it does not deliver the broader 'Bayesian ML / neural networks' scope the catalog description implies. Take it if you want bandits and Bayesian A/B testing specifically; skip it if you want a general Bayesian deep-learning course.
Best for: Data scientists, ML engineers, growth/experimentation analysts, and quantitatively comfortable Python developers who already know basic probability and Bayes rule and want a practical, code-along grounding in the explore-exploit dilemma, multi-armed bandits (epsilon-greedy, UCB1, Thompson sampling), and how Bayesian thinking improves traditional A/B testing.
Skip if: Complete beginners to Python or statistics, people who want a gentle/visual intro to A/B testing without calculus, and anyone expecting broad 'Bayesian machine learning' coverage such as Bayesian neural networks or probabilistic deep learning -- the actual curriculum is centered on A/B testing and bandit algorithms, not neural nets.
About This Course
Apply Bayesian statistics to A/B testing, including conjugate priors, Thompson sampling, and Bayesian neural networks.
What You'll Learn
Curriculum
Course overview, real-world A/B testing applications across marketing/retail/advertising, and the motivation for Bayesian methods.
Bayes' rule, maximum likelihood estimation (Bernoulli and Gaussian), click-through rates, CDFs/percentiles, and statistics-vs-machine-learning distinctions.
Confidence intervals (theory and code), hypothesis testing, z-test theory and implementation, statistical significance and p-values, plus exercises.
Explore-exploit dilemma, epsilon-greedy, optimistic initial values, UCB1 theory and code, and Thompson sampling with Bernoulli and Gaussian rewards, including nonstationary bandits and online learning.
Conjugate-prior exercises and comparative analysis of the different strategies.
Environment setup, Python/coding guidance, learning-strategy lectures, and appendix material that pad the total lecture count.
Prerequisites
- Calculus and probability theory (distributions, conditional probability, Bayes rule)
- Python coding fundamentals (control flow, data structures)
- Working knowledge of NumPy, SciPy, and Matplotlib
Instructor
Lazy Programmer Inc.
Instructor · Udemy
Pros & Cons
Pros
- Clear, well-organized progression from frequentist A/B testing to fully Bayesian bandits -- the most praised aspect in student feedback
- Genuinely teaches the explore-exploit/multi-armed-bandit toolkit (epsilon-greedy, UCB1, Thompson sampling) that is hard to find packaged this practically
- Algorithms are implemented from scratch in Python/NumPy, which builds real intuition rather than hiding the math behind a library
- Strong, durable track record: real 4.3/5 from ~7,982 ratings and ~46,400 students, with the course actively maintained (last updated 2026)
Cons
- Multiple reviewers say the math is worked through too quickly to follow along comfortably, especially given the calculus/probability prerequisites
- The coding portion is described by students as limited and at times overly complex compared with other Udemy ML courses
- Scope is narrower than the catalog description implies -- there is no verified coverage of 'Bayesian neural networks'; it is an A/B-testing and bandits course
- Like most Udemy courses, the list price (~$199.99) is misleading; real value depends on buying during a sale
Alternatives To Consider
Frequently Asked Questions
Is Bayesian Machine Learning in Python: A/B Testing free?
Bayesian Machine Learning in Python: A/B Testing is $12.99. Listed around $12.99 in this catalog; Udemy list price is ~$199.99 and the instructor's own site (deeplearningcourses.com) shows ~$29.99 on sale. Udemy runs frequent discounts, so paying $10-$20 during a sale is realistic and recommended -- do not pay full list price. A Udemy certificate of completion is included; there is no free full-audit option.
Who is Bayesian Machine Learning in Python: A/B Testing for?
Data scientists, ML engineers, growth/experimentation analysts, and quantitatively comfortable Python developers who already know basic probability and Bayes rule and want a practical, code-along grounding in the explore-exploit dilemma, multi-armed bandits (epsilon-greedy, UCB1, Thompson sampling), and how Bayesian thinking improves traditional A/B testing.
What will you learn in Bayesian Machine Learning in Python: A/B Testing?
Frequentist A/B testing foundations: confidence intervals, hypothesis testing, the z-test, statistical significance, and p-values; Maximum likelihood estimation for Bernoulli and Gaussian models, and the difference between classical statistics and a machine-learning framing; The explore-exploit dilemma and why traditional A/B testing wastes traffic; Adaptive bandit algorithms: the epsilon-greedy algorithm, optimistic initial values, and UCB1 (Upper Confidence Bound).
What are the prerequisites for Bayesian Machine Learning in Python: A/B Testing?
Calculus and probability theory (distributions, conditional probability, Bayes rule); Python coding fundamentals (control flow, data structures); Working knowledge of NumPy, SciPy, and Matplotlib.
Is Bayesian Machine Learning in Python: A/B Testing worth it?
Strong, well-reviewed (4.3/5, ~7,982 ratings) for its actual niche -- Bayesian/adaptive A/B testing and multi-armed bandits -- but it assumes comfort with calculus, probability, Bayes rule, and NumPy/SciPy, and it does not deliver the broader 'Bayesian ML / neural networks' scope the catalog description implies. Take it if you want bandits and Bayesian A/B testing specifically; skip it if you want a general Bayesian deep-learning course.
How we reviewed this course
This is an independent editorial assessment by Cursarium, based on Udemy's published course materials and aggregated public learner feedback (last reviewed 2026-06). We have not independently completed the course. Links to providers are standard references, not paid placements.
Sources
- Lazy Programmer / deeplearningcourses.com - official course page (verified syllabus, prerequisites, price)
- Class Central - Bayesian Machine Learning in Python: A/B Testing (rating, student count, sections)
- Udemy - official course listing
- GitHub - tpalczew/Bayesian-Machine-Learning-in-Python-A-B-Testing (independent student notes confirming curriculum topics)