practice a little every day, paws crossed ♡
Interview Questions
Practice 9403 coding, system design and machine learning questions from 546 companies, sorted by role, topic and interview round. Every question has step-by-step hints, a code runner that supports 8 languages and an AI mentor; members also get the full solution walkthrough.
- 9403
- Questions
- 546
- Companies
- 11
- Topics
- 8
- Languages
Showing 541–570 of 781 results
- PinterestMediumSoftware EngineerDesign a Distributed Rate-Limiting Service
Design a highly available, ultra-low-latency distributed rate-limiting service supporting multi-tier rules (user, tenant, route, global) across globally distributed edge gateways.
System DesignOnline Assessmentsystem-designdistributed-systemsrate-limiting - PinterestMediumSoftware EngineerDesign a Multi-Channel Notification System
Design an extensible, resilient multi-channel notification engine (push, email, SMS, in-app) supporting high throughput, deduplication, quiet hours, rate limiting, and provider fallbacks.
System DesignOnline Assessmentsystem-designdistributed-systemsevent-driven - PinterestMediumSoftware EngineerFind minimum shuttle transfers
Find minimum shuttle transfers evaluates algorithm design, data structures, correctness, complexity, edge cases, and implementation details in a realistic interview setting. A strong answer states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.
Coding & AlgorithmsOnline Assessment - PinterestHardMachine Learning EngineerImplement Naive Bayes classifier from scratch
This question evaluates understanding of probabilistic classification, specifically competence in estimating class priors, feature likelihood parameters, and computing posterior scores for Naive Bayes variants.
Machine LearningOnline Assessment - PinterestHardMachine Learning EngineerImplement bagging with decision trees
This question evaluates a candidate's competency in ensemble learning and practical implementation skills, including bootstrap sampling, decision tree base learners, aggregation via majority voting with tie-breaking, and managing data using pure Python lists and standard library routines.
Machine LearningOnline Assessment - PinterestMediumSoftware EngineerMark and Compact a Heap-Indexed Subtree
This problem tests array manipulation, heap-based tree traversal, and stable partitioning techniques while requiring memory efficiency without modifying the original input.
Coding & AlgorithmsOnline AssessmentArraysTreesHeap - Point72HardData ScientistBuild the auction status table
This problem tests advanced SQL skills, specifically the ability to perform window functions, handle state transitions, and aggregate time-series data to reconstruct the final status of entities.
Data Manipulation (SQL/Python)Online AssessmentSQLWindow FunctionsData Aggregation - Point72MediumQuantitative ResearcherCalibrate the Risk-Aversion Parameter
Calibrate mean-variance risk aversion to target risk and out-of-sample utility while accounting for units, scaling, constraints, and regimes.
Statistics & MathOnline Assessment - Point72MediumQuantitative ResearcherChoose Practical Portfolio Constraints
Specify practical stat-arb constraints for neutrality, exposure, concentration, turnover, liquidity, and borrow, including feasibility checks.
Statistics & MathOnline Assessment - Point72MediumQuantitative ResearcherCompare Missing-Value Strategies for Linear Models
Compare mean, random empirical, and indicator-assisted imputation for linear models under MCAR, MAR, and MNAR without training leakage.
Machine LearningOnline Assessment - Point72MediumQuantitative ResearcherCompare Two Equity Risk Models
Compare two equity risk models out of sample using forecast calibration, residual structure, stability, coverage, regimes, and portfolio impact.
Machine LearningOnline Assessment - Point72MediumQuantitative ResearcherDerive Annualized Portfolio Volatility
Derive portfolio volatility from factor covariance and stock-specific variance, then annualize it with consistent horizons and units.
Statistics & MathOnline Assessment - Point72MediumQuantitative ResearcherEncode Categorical Variables Across Model Families
Choose categorical encodings for linear, tree, and neural models while handling intercept rank, unseen values, and high cardinality.
Machine LearningOnline Assessment - Point72MediumQuantitative ResearcherEstimate Factor Returns and Residual Returns
Derive weighted factor-return estimates from a sample, then compute residual returns across a larger trading universe with stable linear algebra.
Statistics & MathOnline Assessment - Point72HardSoftware EngineerEvaluate Defensive Testing and Pair Programming
Tests your ability to critically evaluate software quality practices—defensive automated testing versus pair programming—and construct a risk-adjusted, cost-effective engineering adoption strategy.
Software Engineering FundamentalsOnline AssessmentSoftware EngineeringTestingAgile - Point72HardData ScientistExplain and tune decision trees robustly
The question evaluates a candidate's understanding of CART decision tree mechanics, split criteria and surrogate splits for missing values, hyperparameter tuning and pruning, overfitting diagnostics, preprocessing for large feature sets and high‑cardinality categoricals, and criteria for choosing ensemble methods within the Machine Learning domain.
Machine LearningOnline Assessment - Point72EasyData ScientistFind kth missing integer and redundant operations
This paired question evaluates array and algorithmic skills — specifically order-statistics and missing-number reasoning for the k-th missing positive, and time-window aggregation with frequency tracking for detecting redundant log events — within the coding & algorithms domain.
Coding & AlgorithmsOnline Assessment - Point72MediumQuantitative ResearcherFormulate a Single-Period Stat-Arb Objective
Formulate a convex single-period statistical-arbitrage objective balancing expected return against covariance risk, with consistent units.
Statistics & MathOnline Assessment - Point72HardData EngineerImplement Election Report and Banking Pipeline
This multipart question evaluates data engineering competencies including SQL report design for complex aggregation and ranking, plus PySpark-based ETL and transaction-level analytics.
Coding & AlgorithmsOnline Assessment - Point72HardData ScientistImplement composition and mixin utilities
This problem tests proficiency in functional composition, Python metaclass/decorator patterns, and custom serialization logic, focusing on handling flexible arguments and object introspection.
Coding & AlgorithmsOnline AssessmentPythonFunctional ProgrammingSerialization - Point72MediumQuantitative ResearcherLinearize an L1 Trading Penalty
Linearize weighted absolute trading costs with auxiliary variables, complete LP constraints, the correct objective sign, and an equivalence proof.
Statistics & MathOnline Assessment - Point72HardSoftware EngineerMaximize Fixed Positions After Deletions
This problem tests your ability to use dynamic programming and data structures to maximize elements in a subsequence that align with their new indices after removing elements.
Coding & AlgorithmsOnline AssessmentDynamic ProgrammingGreedyData Structures - Point72MediumQuantitative ResearcherModel Trading Frictions in Portfolio Optimization
Extend a stat-arb objective with unit-consistent commissions, spread, slippage, market impact, turnover, borrow, and concentration costs.
Statistics & MathOnline Assessment - Point72HardData ScientistPrice a coin-doubling game rationally
This question evaluates understanding of probability distributions, divergent expected values, utility theory, and optimal betting strategies (Kelly staking) within the Statistics & Math domain for a Data Scientist role.
Statistics & MathOnline Assessment - Point72HardSoftware EngineerSimulate a Deterministic Finite Automaton
Implement and run a Deterministic Finite Automaton (DFA) simulator that parses state transitions over a binary alphabet and determines if input strings are accepted.
Coding & AlgorithmsOnline AssessmentFinite AutomataState MachineDesign - Point72EasyData EngineerSolve SQL and PySpark Data Tasks
This question tests your ability to handle data cleaning, filtering, and aggregation using both SQL and PySpark syntax on a transaction dataset.
Coding & AlgorithmsOnline AssessmentSQLPySparkData-Cleaning - Qualified HealthMediumSoftware EngineerDesign Notifications for One Million Internal Producer Services
Design notification ingestion and delivery for a million internal producers, separating service-count scale from throughput, bursts, and fanout.
System DesignOnline Assessment - Quantbot TechnologiesHardData ScientistBuild a Data-Cleaning and Machine-Learning Pipeline Without Leakage
Design schema-aware cleaning, appropriate data splits, training-only fitted transformations, reusable inference state, and validation for missing or unseen inputs.
Machine LearningOnline Assessment - Quantbot TechnologiesHardData ScientistImplement GLM Training and Prediction from an Explicit Family and Link
Explain a from-scratch generalized linear model through family and link selection, consistent loss and gradients, numerical stability, and prediction semantics.
Machine LearningOnline Assessment - Qube Research & TechnologiesHardData ScientistImplement and Tune KNN Classifier
This question evaluates a candidate's competency in implementing and tuning the K-nearest neighbors algorithm, covering data preprocessing, distance-based classification, model evaluation, and hyperparameter selection.
Machine LearningOnline Assessment
Pinterest
Point72
Qube Research & Technologies