X
Lean, fast loops with a strong bias toward shipping — practical coding, systems questions, and direct conversations with the team you would join.
Typical loop
- 1Recruiter screen
- 2Technical phone screen
- 3Onsite: two coding rounds
- 4System design round
- 5Team and hiring-manager conversation
Questions
Callback's practice questions and the LeetCode questions X has been asking, filtered together.
Asked on LeetCode
51 questions · all time
- Minimum Genetic MutationmediumHash TableStringBreadth-First SearchBidirectional Searchfrequency 100.0
- Design TwittermediumHash TableLinked ListDesignHeap (Priority Queue)frequency 97.0
- Flatten Nested List IteratormediumStackTreeDepth-First SearchDesign+2frequency 97.0
- Invalid TweetseasyDatabasefrequency 97.0
- LRU CachemediumHash TableLinked ListDesignDoubly-Linked Listfrequency 97.0
- Merge IntervalsmediumArraySortingQuicksortfrequency 97.0
- Trapping Rain WaterhardArrayTwo PointersDynamic ProgrammingStack+1frequency 97.0
- Tweet Counts Per FrequencymediumHash TableStringBinary SearchDesign+2frequency 97.0
- Alien DictionaryhardArrayStringDepth-First SearchBreadth-First Search+3frequency 93.7
- Best Meeting PointhardArrayMathSortingMatrixfrequency 93.7
- Binary GapeasyBit Manipulationfrequency 93.7
- Count Student Number in DepartmentsmediumDatabasefrequency 93.7
- Count Sub IslandsmediumArrayDepth-First SearchBreadth-First SearchUnion-Find+1frequency 93.7
- Customer Placing the Largest Number of OrderseasyDatabasefrequency 93.7
- Design Authentication ManagermediumHash TableLinked ListDesignDoubly-Linked Listfrequency 93.7
- Design SkiplisthardLinked ListDesignfrequency 93.7
- Finding the Users Active MinutesmediumArrayHash Tablefrequency 93.7
- Flatten 2D VectormediumArrayTwo PointersDesignIteratorfrequency 93.7
- Happy NumbereasyHash TableMathTwo PointersFloyd's Cycle Finding Algorithmfrequency 93.7
- Implement Trie (Prefix Tree)mediumHash TableStringDesignTriefrequency 93.7
- Insert Delete GetRandom O(1)mediumArrayHash TableMathDesign+1frequency 93.7
- Integer to RomanmediumHash TableMathStringfrequency 93.7
- Investments in 2016mediumDatabasefrequency 93.7
- Kth Smallest Element in a Sorted MatrixmediumArrayBinary SearchSortingHeap (Priority Queue)+1frequency 93.7
- Lowest Common Ancestor of a Binary Search TreemediumTreeDepth-First SearchBinary Search TreeBinary Tree+2frequency 93.7
- Masking Personal InformationmediumStringfrequency 93.7
- Max Points on a LinehardArrayHash TableMathGeometry+2frequency 93.7
- Merge k Sorted ListshardLinked ListDivide and ConquerHeap (Priority Queue)Merge Sort+1frequency 93.7
- Minimum Elements to Add to Form a Given SummediumArrayGreedyfrequency 93.7
- Minimum Number of Steps to Make Two Strings AnagrammediumHash TableStringCountingfrequency 93.7
- Multiply StringsmediumMathStringSimulationfrequency 93.7
- Number of Black BlocksmediumArrayHash TableEnumerationfrequency 93.7
- Number of Connected Components in an Undirected GraphmediumDepth-First SearchBreadth-First SearchUnion-FindGraph Theoryfrequency 93.7
- One Edit DistancemediumTwo PointersStringfrequency 93.7
- Pascal's TriangleeasyArrayDynamic Programmingfrequency 93.7
- Permutation SequencehardMathRecursionfrequency 93.7
- Process Tasks Using ServersmediumArrayHeap (Priority Queue)frequency 93.7
- Rectangles AreamediumDatabasefrequency 93.7
- Regular Expression MatchinghardStringDynamic ProgrammingRecursionfrequency 93.7
- Remove All Occurrences of a SubstringmediumStringStackSimulationfrequency 93.7
- Reverse Linked ListeasyLinked ListRecursionfrequency 93.7
- The Skyline ProblemhardArrayDivide and ConquerBinary Indexed TreeSegment Tree+4frequency 93.7
- Time Needed to Buy TicketseasyArrayQueueSimulationfrequency 93.7
- Trapping Rain Water IIhardArrayBreadth-First SearchHeap (Priority Queue)Matrixfrequency 93.7
- Tree NodemediumDatabasefrequency 93.7
- Valid ParentheseseasyStringStackBracket Sequencesfrequency 93.7
- Validate IP AddressmediumStringfrequency 93.7
- Wildcard MatchinghardStringDynamic ProgrammingGreedyRecursionfrequency 93.7
- Word Break IIhardArrayHash TableStringDynamic Programming+3frequency 93.7
- Largest Plus SignmediumArrayDynamic Programmingfrequency 66.1