Jane Street Coding & Algorithms Interview Questions
Practice the exact questions companies are asking right now.
"I got asked a hardcore MCM DP question and I saw it on PracHub as well. Solved that question in 5 minutes. Without PracHub I doubt I could solve it in 5 hours. Though somehow didn't get hired, perhaps I guess I solved it too fast? /s"
"Believe me i'm a student here jn US. Recently interviewed for MSFT. They asked me exact question from PracHub. I saw it the night before and ignored it cause why waste time on random sites. I legit wanna go back and redo this whole thing if I had chance. Not saying will work for everyone but there is certainly some merit to that website. And i'm gonna use it in future prep from now on like lc tagged"
"10 years of experience but never worked at a top company. PracHub's senior-level questions helped me break into FAANG at 35. Age is just a number."
"I was skeptical about the 'real questions' claim, so I put it to the test. I searched for the exact question I got grilled on at my last Meta onsite... and it was right there. Word for word."
"Got a Google recruiter call on Monday, interview on Friday. Crammed PracHub for 4 days. Passed every round. This platform is a miracle worker."
"I've used LC, Glassdoor, and random Discords. Nothing comes close to the accuracy here. The questions are actually current — that's what got me. Felt like I had a cheat sheet during the interview."
"The solution quality is insane. It covers approach, edge cases, time complexity, follow-ups. Nothing else comes close."
"Legit the only resource you need. TC went from 180k -> 350k. Just memorize the top 50 for your target company and you're golden."
"PracHub Premium for one month cost me the price of two coffees a week. It landed me a $280K+ starting offer."
"Literally just signed a $600k offer. I only had 2 weeks to prep, so I focused entirely on the company-tagged lists here. If you're targeting L5+, don't overthink it."
"Coaches and bootcamp prep courses cost around $200-300 but PracHub Premium is actually less than a Netflix subscription. And it landed me a $178K offer."
"I honestly don't know how you guys gather so many real interview questions. It's almost scary. I walked into my Amazon loop and recognized 3 out of 4 problems from your database."
"Discovered PracHub 10 days before my interview. By day 5, I stopped being nervous. By interview day, I was actually excited to show what I knew."
"I recently cleared Uber interviews (strong hire in the design round) and all the questions were present in prachub."
"The search is what sold me. I typed in a really niche DP problem I got asked last year and it actually came up, full breakdown and everything. These guys are clearly updating it constantly."
Collapsible Code Editor: Brace Matching and Toggle
This question tests stack-based parsing and stateful data structure design through a two-part brace-matching and collapsible editor problem. It evalua...
Implement a Circular Buffer
This question evaluates understanding of data structures and buffer management, specifically FIFO semantics, fixed-capacity storage, wraparound indexi...
Code Editor with Block Shrink and Expand (Code Folding)
Implement the core of a code editor (similar to VS Code) that supports code folding: collapsing ("shrink") and restoring ("expand") indentation-based ...
Transform sparse time-code stream to dense rows
Problem You are given: - A fixed set of M distinct codes (strings). The column order of the output matrix is the lexicographic order of these codes. -...
Optimize trade PnL table updates
This question evaluates understanding of incremental aggregation and state management, including handling overlapping predicates, caching expensive or...
Field Layout: getOffset and insert
An object's binary layout is defined by an ordered list of fields. Each field has a unique name and a size in bytes. Fields are packed contiguously st...
Marketplace Data Store: Order Matching and End-of-Day Reconciliation
Marketplace Data Store: Order Matching and End-of-Day Reconciliation You are building the core of a marketplace where sellers list individual units of...
Implement Connect Four with bottom push-up
Implement a Connect Four variant with bottom push-up. In standard Connect Four a dropped disc falls to the lowest empty cell of a column. In this vari...
Sort trade executions into a canonical order
You are building a small component in a trading system that consumes trade execution records from an upstream feed. The records may arrive out of orde...
Board Simulation: Bottom-Insert Pieces with Uniform Row and Column Detection
Board Simulation: Bottom-Insert Pieces with Uniform Row and Column Detection You must simulate a 2-D game board with R rows and C columns. Each cell i...
Solve queue switch and coin change puzzles
This entry contains two separate interview-style quantitative/algorithmic questions. --- 1. Queue switching decision problem You are standing in a sin...
Connect-N on an Infinite Board with Gravity
You are asked to implement a variant of the classic Connect Four game, played on an unbounded board. Game Rules - The board consists of vertical colum...
Merge Two Insertion Diffs in Linear Time
A text-editing system represents changes to a document as insertion diffs. An insertion diff is a set of (position, value) pairs, where each pair mean...
Decode an Encrypted Paragraph Tree
Decode an Encrypted Paragraph Tree A document is stored as a tree of paragraphs. Each node holds a paragraph text — a string of lowercase English lett...
Evaluate a Tokenized Arithmetic Expression
Evaluate a Tokenized Arithmetic Expression You are given an arithmetic expression that has already been tokenized for you — you do not need to write a...
Snake Game: Minimum Moves to Reach the Apple
Snake Game: Minimum Moves to Reach the Apple You are simulating the classic Snake game on a grid with R rows and C columns. Cells are identified as (r...
Reach a Target Using Each Number At Most Once
Reach a Target Using Each Number At Most Once You are given an array of integers nums and an integer target. Decide whether you can build an arithmeti...
Stack Machine Interpreter with Typed Int and String Values
You are building an interpreter for a simple stack machine. The machine has a single stack, and every value on the stack is one of exactly two primiti...
Bottom-Insertion Connect Game: Detect the First k-in-a-Row Winner
Two players, B and R, take turns dropping pieces onto a board that covers the upper half-plane of an integer grid. Columns are indexed by arbitrary in...
Optimal Stopping for Die Rolls That Bust on Perfect Squares
You repeatedly roll a fair six-sided die and keep a running cumulative sum $S$ of all the values rolled so far (starting from $S = 0$ before the first...