Backend Engineer Coding & Algorithms Interview Questions
Practice 25 real Coding & Algorithms interview questions for Backend Engineer roles. From companies including Bytedance, Target, Applied, Chime, Coinbase.
"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."
Resolve Dependent Addition Equations
Resolve Dependent Addition Equations Problem Implement resolveEquations(equations) -> output. Each input string defines one variable as a sum of nonne...
Execute a TTL Key-Value Store with Transactions
Execute a TTL Key-Value Store with Transactions Problem Implement executeKvCommands(commands) -> outputs for an in-memory key-value store. Commands ar...
Find the Closest Candidate String by Edit Distance
Find the Closest Candidate String by Edit Distance Problem Implement closestCandidates(candidates, queries) -> results. The edit distance between two ...
Count Lucky Numbers in an Inclusive Range
Count Lucky Numbers in an Inclusive Range Problem A positive integer x is lucky when it is divisible by floor(sqrt(x)). Implement countLuckyNumbers(le...
Implement a Stateful Trading Order Manager
Build a stateful trading order manager with deterministic command results, lifecycle transitions, bulk cancellation, and live-order display. Assign us...
Fix the Broken Search Filter in a Book Catalog API
This question tests a backend engineer's ability to implement correct filtering logic, including case-insensitive substring matching, whitespace trimm...
SQL: Students Above Average and Passing Every Subject
This question tests practical SQL skills, specifically the use of aggregate functions and conditional filtering across grouped data. It evaluates the ...
Count and Rank Words in a Paragraph
Count case-insensitive ASCII words in a paragraph and return deterministic frequency rankings. Tokenize maximal letter runs, normalize to lowercase, s...
Replace Dashes With Nearest Letters
This question evaluates a candidate's competence in grid traversal, distance computation using Manhattan metrics, and handling tie-breaking rules incl...
Distribute Annual Revenue Across Twelve Months
Distribute Annual Revenue Across Twelve Months Implement distribute_revenue(annual_cents). The input is a non-negative integer amount of annual revenu...
Determine If One Binary Tree Is a Substructure of Another
This question evaluates practical tree traversal skills and the ability to implement structural matching between two binary trees. It tests recursive ...
Reorder Search Results for Provider Diversity
Build a function that paginates ordered provider listings for a telehealth marketplace. Each input record is a CSV string in the format: provider_id, ...
Implement tag matcher and filesystem
This interview reportedly included two coding problems: 1. Tag matching in text Given a sentence and a list of tags or keywords, return the tags th...
Convert IPv4 Ranges to CIDR Blocks
Implement a function that summarizes a consecutive IPv4 address range using the smallest possible list of CIDR blocks. You are given: - start_ip: a va...
Solve coding and AI-assisted tasks
This set evaluates algorithmic problem-solving across arrays, immutable linked-list interfaces, parent-pointer tree traversal, string validity via min...
Solve classic backend coding problems
This multi-part question evaluates algorithmic problem solving and implementation skills, including string parsing and segmentation, combinatorial rea...
Implement Popular and Ranked Voting
You are given ranked ballots in aggregated form. Each key is an ordered tuple of candidate names representing one voter's preference from highest to l...
Compare Strings With Deletions
You are given two strings s and t. Each string may contain lowercase letters and the special character #. A # deletes the closest non-deleted characte...
Solve Bracket Matching and Tree Width
This composite question evaluates proficiency with core data structures and algorithmic reasoning, covering string-based bracket validation (sequence ...
Find First Anagram Occurrence
Given two strings text and pattern, return the starting index of the first substring in text that is an anagram of pattern. If no such substring exist...