Topic
Coding & Algorithms interview questions
3276 Coding & Algorithms questions from 366 companies, with hints, runnable code and solution walkthroughs.
273 easy2539 medium464 hard
Coding & Algorithms interview questions by the numbers
Last updated
Katkat has 3,276 Coding & Algorithms interview questions from 366 companies; the most come from Amazon (7%), Meta (7%) and Google (6%). By difficulty: 8% easy, 78% medium and 14% hard. The most common round is Technical Screen (52%). Frequent concepts include Algorithms, Data Structures, Arrays and Greedy.
Companies (366)
Difficulty
- Easy8% · 273
- Medium78% · 2539
- Hard14% · 464
Interview rounds
- Technical Screen52% · 1706
- Onsite33% · 1080
- Online Assessment13% · 427
- HR Screen1% · 37
- Other1% · 26
Roles
- Software Engineer80% · 2629
- Machine Learning Engineer8% · 253
- Data Scientist7% · 241
- Data Engineer1% · 45
- Backend Engineer1% · 26
Frequent concepts
- Algorithms9% · 302
- Data Structures7% · 228
- Arrays5% · 176
- Greedy5% · 164
- Optimization5% · 151
- Hash Map4% · 124
Most mentioned in interview experiences
- 1.Solve Algorithmic Challenges in Online Coding Assessments15 reports
- 2.Solve LeetCode string and list problems11 reports
- 3.Solve sliding-window and heap problems8 reports
- 4.Implement LRU cache with O(1) ops7 reports
- 5.Implement and Analyze an LRU Query Cache6 reports
- 6.Determine Length of Longest Unique Substring5 reports
- 7.Match-3 Grid: Find Horizontal and Vertical Runs, Then Clear and Drop Cells5 reports
- 8.Design a single- and multi-threaded web crawler4 reports
- 9.Find an Exit in a URL Maze4 reports
- 10.Find deployable slots in a recurring week from allowed and freeze windows4 reports
Counted from 781 candidate interview experiences on Katkat. How we collect and count
Showing 2761–2790 of 3276 results
Determine the first k non-overlapping deployment windows across a 3-week search horizon by mapping weekly recurring local allow and freeze rules into a repeating UTC timeline.
StripeSoftware EngineerCoding & AlgorithmsOnline AssessmentA coding exercise on a recurring 10,080-minute week: combine allowed and freeze deployment windows into deployable slots, then add per-window time-zone offsets, the current time, a lead time, a minimum slot length and a cap of k results. It tests interval merging and subtraction, wrap-around at the week boundary and careful edge-case handling.
StripeSoftware EngineerCoding & AlgorithmsOnsiteThis question tests the ability to model entity relationships using a graph representation and implement a traversal algorithm to identify connected components based on shared identity fields.
StripeSoftware EngineerCoding & AlgorithmsTechnical ScreenThis question evaluates the ability to compute weighted field-based similarity and reason about adjacency relationships in an undirected graph, testing competencies in similarity scoring, record linkage, and basic graph traversal.
StripeSoftware EngineerCoding & AlgorithmsTechnical ScreenThis problem tests your ability to model relationships as a graph and compute connected components based on weighted similarity scores between user records.
StripeSoftware EngineerCoding & AlgorithmsTechnical ScreenThis problem tests your ability to manipulate time intervals, handle recurring weekly schedules, and perform intersection logic between availability windows and existing booked appointments.
StripeSoftware EngineerCoding & AlgorithmsTechnical ScreenThis problem tests your ability to find the shortest path in a weighted graph under a specific constraint on the number of edges (stops).
StripeSoftware EngineerCoding & AlgorithmsTechnical ScreenTests algorithm design and combinatorial search to settle multi-party debts with the minimum number of transfer transactions.
StripeSoftware EngineerCoding & AlgorithmsTechnical ScreenImplement a subscription proration and billing reconciliation engine that generates line items across plan changes and computes the outstanding balance against posted payments.
StripeSoftware EngineerCoding & AlgorithmsOnsiteTests practical software engineering skills in parsing JSON data, constructing batch HTTP requests, mapping returned attributes (such as color codes to coordinate points), and handling API errors.
StripeSoftware EngineerCoding & AlgorithmsTechnical ScreenThis problem tests your ability to design a custom parser and recursive string processor that handles nested patterns while enforcing strict input validation.
StripeSoftware EngineerCoding & AlgorithmsOnsiteThis problem tests the ability to manage stateful datacenter metadata and implement a routing algorithm that prioritizes proximity (Haversine distance) while respecting capacity constraints.
StripeSoftware EngineerCoding & AlgorithmsOnline AssessmentThis problem tests your ability to manipulate 2D bit arrays, implement Run-Length Encoding (RLE) for data compression, and perform grid-based coordinate transformations.
StripeSoftware EngineerCoding & AlgorithmsOnline AssessmentThis question evaluates a candidate's ability to implement and reason about the Luhn checksum, multi-network payment card format validation, combinatorial completion for redacted digits, single-error correction models, and efficient search/pruning with deterministic duplicate avoidance.
StripeSoftware EngineerCoding & AlgorithmsOnline AssessmentThis question evaluates a candidate's ability to implement robust data-processing and numeric computation logic for a multi-part cost calculator, covering input validation, per-item discounts and tax, sorting semantics, multi-currency conversion, and precise monetary rounding.
StripeSoftware EngineerCoding & AlgorithmsTechnical ScreenThis question evaluates design and implementation skills for a stateful connection router, focusing on round-robin load distribution, connection lifecycle handling (duplicate connects, disconnects, shutdowns), and per-target capacity and mapping management.
StripeSoftware EngineerCoding & AlgorithmsOnline AssessmentThis question evaluates a candidate's competency in streaming algorithms, per-user reservoir sampling, probabilistic reasoning and proof of correctness, concurrent/distributed merging, and engineering trade-offs for memory and amortized update efficiency.
StripeData ScientistCoding & AlgorithmsTechnical ScreenThis question evaluates string parsing, record linkage, and algorithmic matching skills for data reconciliation tasks, including handling messy memo text, exact amount matches, and tie-breaking by earliest due date.
StripeData ScientistCoding & AlgorithmsTechnical ScreenThis problem tests the ability to implement a multi-pass matching algorithm that prioritizes exact identifier matches before applying fuzzy numeric heuristics.
StripeSoftware EngineerCoding & AlgorithmsTechnical ScreenThis problem tests your ability to use dynamic programming to minimize a total cost function that incorporates both intrinsic production costs and location-based transition penalties.
StripeSoftware EngineerCoding & AlgorithmsTechnical ScreenTests parsing RFC 4180-compliant CSV records containing hierarchical tasks and rendering an arbitrarily nested forest with proper tree line prefixes (`├── `, `└── `, and `│ `).
StripeSoftware EngineerCoding & AlgorithmsTechnical ScreenThis question evaluates graph algorithms and pathfinding competencies, multi-criteria optimization and weighting, data structure selection, heuristic design, handling dynamic updates and closures, and correctness and edge-case reasoning for route planning.
StripeSoftware EngineerCoding & AlgorithmsTechnical ScreenThis problem tests your ability to manage stateful account data, handle time-ordered transaction processing, and implement basic validation logic for financial integrity.
StripeSoftware EngineerCoding & AlgorithmsTechnical ScreenThis question evaluates a candidate's ability to implement stateful stream processing and event handling, including applying time-scoped fraud rules to authorization requests, maintaining chronological ordering, and producing verified outputs via unit tests.
StripeSoftware EngineerCoding & AlgorithmsTechnical ScreenImplement a request interpolator that traverses nested request payloads and URLs to replace placeholder variables with runtime IDs while preserving native data types.
StripeSoftware EngineerCoding & AlgorithmsTechnical ScreenImplement a stateful command processor to register data centers, update their operational health, and route incoming requests to the nearest healthy data center using the Haversine distance formula.
StripeSoftware EngineerCoding & AlgorithmsOnline AssessmentThis problem tests your ability to navigate hierarchical structures (a tree of accounts) and perform efficient permission aggregation using set operations.
StripeSoftware EngineerCoding & AlgorithmsTechnical ScreenImplement a payment event processor for split-tender retail purchases, where each charge spends a customer's gift cards before billing the rest to a credit card. It tests precise simulation: earliest-expiry card priority with lexicographic tie-breaks, ZIP-range surcharges on the credit card portion, refunds split between card and store credit, and exact output formatting.
StripeSoftware EngineerCoding & AlgorithmsTechnical ScreenCompute available deployment windows by merging allowed and blocked half-open intervals, subtracting overlaps, and returning maximal sorted nonempty ranges.
StripeSoftware EngineerCoding & AlgorithmsOnline AssessmentProcess a chronological log of theme-park wristband events that spend expiring ride credits before a linked card, apply per-zone card surcharges, and split refunds between the card and new store credit.
StripeSoftware EngineerCoding & AlgorithmsTechnical Screen