Machine Learning Scientist Interview Experience
Process
They asked me to implement a sparse matrix from scratch, without relying on any existing matrix or linear algebra libraries. This required designing an efficient internal data structure to store only the non-zero elements, rather than allocating memory for the entire matrix. In addition to the core representation, I needed to implement both addition and multiplication operations, making sure they handled sparsity correctly, maintained good performance, and produced accurate results even when matrices had different sparsity patterns.
Questions
They asked me to implement a sparse matrix from scratch, without relying on any existing matrix or linear algebra libraries. This required designing an efficient internal data structure to store only the non-zero elements, rather than allocating memory for the entire matrix. In addition to the core representation, I needed to implement both addition and multiplication operations, making sure they handled sparsity correctly, maintained good performance, and produced accurate results even when matrices had different sparsity patterns.
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Interview Statistics
The following metrics were computed from 1 interview experience for the Pinterest Machine Learning Scientist role.
Success Rate
Pinterest's interview process for their Machine Learning Scientist roles is extremely selective, failing the vast majority of engineers.
Experience Rating
Candidates reported having very good feelings for Pinterest's Machine Learning Scientist interview process.
Pinterest Work Experiences
- 5.0Friendly environment with great benefitsSoftware Engineer 2 • Current EmployeePalo Alto, CASeptember 8, 2026Pros: There are extremely friendly people, great benefits, and the ability to own large projects and innovate.Cons: Offices are pretty empty due to WFH, and the overall direction of the company seems uncertain at times.
- 5.0Best workplace everSoftware Engineer • Current EmployeeSeattle, Washington, United StatesNovember 17, 2022Pros: The workplace is very supportive of individuals, and the work is interesting.Cons: No cons for this job.
- 2.0Horrible WLB and bossy managementSoftware Engineer • Former EmployeeApril 1, 2024Pros: Interesting technological challenges. Many talented people.Cons: Horrible work-life balance. Be ready to work 80 hours a week if on any ad teams. Mediocre middle and low-tier management. Pushy and bossy, this yields teammates to compete for little things and ruins culture.
Pinterest Interview Questions
