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Coding questions · Upstart
Decrypt a twice-encrypted message using known pairs
This question evaluates the ability to reconstruct and compose bijective character-substitution mappings, testing competency in string manipulation, mapping inference, and basic cipher reasoning.
Coding questions · Netflix
Dedupe titles in per-shelf viewport
This question evaluates algorithmic problem-solving and state management for streaming deduplication with order preservation, testing competencies in data structures, deterministic filtering, and handling constrained visibility windows.
Coding questions · Salesforce
Deduplicate a Linked List
This question evaluates proficiency in linked list manipulation, in-place data structure modification, and reasoning about time-space trade-offs for removing duplicate elements.
Coding questions · Meta
Define and analyze new-vs-existing activity
This question evaluates a candidate's competency in cohort definition, time-series event aggregation, use of window functions, cohort-level weighting and bias-aware analytics using SQL and Python.
Coding questions · Meta
Define and compute shop visibility in SQL
This question evaluates the ability to define and compute shop-level visibility KPIs in SQL, testing skills in metric design (visibility_rate and impression_share), deduplication, session/window filtering, and data-quality concerns such as late-arriving events and bot filtering.
Coding questions · Meta
Define and query shop visibility
This question evaluates a candidate's ability to design and compute a session‑level visibility metric using SQL and data manipulation techniques, covering joins, date/window handling, deduplication, aggregations, and metric validation.
Coding questions · Applied Intuition
Delete duplicate files via DFS
This question evaluates a candidate's skills in file-system traversal using DFS/backtracking, duplicate detection across hierarchical directories, and algorithmic techniques such as hashing and efficient data-structure use.
Coding questions · Cohere
Delete One '5' From a Digit String to Get the Largest Number
Given a digit string containing at least one 5, delete exactly one 5 so the remaining string has the largest possible numeric value, keeping any leading zeros. This intern online-assessment problem tests reasoning about how each digit position affects a number and careful handling of repeated digits.
Coding questions · Glean
Delete the Fewest Parentheses to Balance a String of Only Open and Close Brackets
Given a string of only open and close parentheses, delete the fewest characters so the rest is balanced and return the resulting string, using standard left-to-right matching to define a unique answer. Tests bracket matching, linear-time scanning and careful handling of leftover unmatched characters.
Coding questions · Amazon
Derive Key Business Metrics Using SQL or Python
This question evaluates data manipulation and analytical querying skills, including joins, aggregations, conditional classification, and running-window computations in the Data Manipulation (SQL/Python) domain.
Coding questions · Amazon
Design 2D DP on a DAG
Design 2D DP on a DAG 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 questions · Optiver
Design a balloon stability tracker
This question evaluates event-driven simulation, time-ordered state management, floating-point numerical evaluation of aggregate functions, and data-structure design for tracking dynamic object states and stability thresholds; it falls under the Coding & Algorithms domain, specifically simulation, event processing, and algorithmic data structures.
Coding questions · Meta
Design a bank system with scheduled transfers
This question evaluates object-oriented design and stateful system skills, including time-ordered event processing, scheduling and cancellation semantics, balance accounting, and top-k aggregation using appropriate data structures.
Coding questions · Tesla
Design a contiguous segment allocator
This question evaluates a candidate's competency in designing and implementing efficient data structures for interval management, contiguous memory allocation, fragmentation handling, tag-based resource tracking, and algorithmic complexity analysis.
Coding questions · Applied Intuition
Design a coupon pricing engine
This question evaluates software design and algorithmic problem-solving skills focused on pricing logic, including handling financial rounding, discount ordering, eligibility criteria across item categories, and time/space complexity analysis.
Coding questions · Bloomberg
Design a data structure for dynamic top‑K frequency
This question evaluates data structure and algorithm design skills, focusing on frequency counting, dynamic maintenance of top-K elements, and efficient update and query operations in a multiset within the Coding & Algorithms domain.
Coding questions · Abnormal Security
Design a duplicate-file removal algorithm
Design a duplicate-file removal algorithm 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 questions · Amazon
Design a fixed-capacity circular queue
This question evaluates understanding of fixed-capacity circular queue data structures, array-based indexing, modular arithmetic, and the requirement for constant-time (O(1)) enqueue/dequeue operations.
Coding questions · Amazon
Design a hierarchical locking tree
This interview question evaluates algorithm design, data structures, correctness, complexity, edge cases, and implementation details in a realistic interview setting. A strong answer for Design a hierarchical locking tree states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.
Coding questions · DoorDash
Design a hierarchical path registry
Design a hierarchical path registry 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 questions · SoFi
Design a key-value store with getLast
Design a key-value store with getLast 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 questions · Adobe
Design a nested-list iterator
This question evaluates the ability to implement an efficient iterator over nested lists, testing skills in iterator state management, lazy traversal, explicit stack usage, and algorithmic complexity reasoning.
Coding questions · OpenAI
Design a persistent key-value store
This question evaluates a candidate's ability to design persistent storage and in-memory data structures, covering serialization of arbitrary values, medium/interface design for byte-level persistence, crash-consistent flushing, error handling, and performance and complexity analysis.
Coding questions · Robinhood
Design a referral leaderboard with chain-based counts
This question evaluates a candidate's ability to model and compute transitive referral counts using graph-like structures and efficient data structures, testing skills in algorithm design, counting, and sorting within the Coding & Algorithms domain.