Capital One Interview Questions
Practice 309 real Capital One interview questions for 2026 — Capital One interview questions drawn from actual interviews with detailed solutions to power your interview preparation. This collection emphasizes coding and system-design first (algorithms, backend reliability, event processing and low-latency services), while also covering analytics, SQL, behavioral, and product-focused problems you’ll see across roles. Expect screeners, timed online assessments, and a multi-interview Power Day that evaluates coding fluency, production-quality system thinking, and business sense. For Software Engineers, interview themes center on banking-grade system design: highly reliable account-balance services, cross-region event processing, virtual card and mobile-banking backends, plus algorithmic coding problems. Data Scientist rounds lean heavily on data cleaning and preprocessing, merging messy housing and flight datasets, responsible predictive modeling (price and delay/watchlist models), and business-case diagnostics for product decisions. Machine Learning Engineers will face model-deployment and monitoring challenges, low-latency inference design, card-type detection work, and applied algorithmic tasks. Product and data roles focus on product design for cards, acquisition strategy, experiments, and metric-driven tradeoffs. Prep by prioritizing end-to-end solutions: code correctness, clear system assumptions, data hygiene, and crisp business communication.

"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."
Write SQL to compute campaign net revenue
Using the schema and sample data below, write SQL to produce, for each campaign_id and segment, the following metrics for August 2025: total_reached, ...
Find top category per region in Aug 2025
You are given the following schema and sample data. Schema: - customers(customer_id INT, name TEXT, region TEXT) - orders(order_id INT, customer_id IN...
Assess 3.4M target and design experiments
This question evaluates skills in growth analytics, market sizing (TAM→SAM→SOM), funnel modeling, unit economics (CAC/LTV), capacity planning, and exp...
Implement minimal-cost overtime/contractor allocation
You must cover H extra engineering hours this week at minimum cost using employee overtime and optional contractors. Each employee i has a maximum ove...
Write SQL for theme-park revenue and visits
You are given theme-park ticketing and visits data. Write SQL to answer the following, using the sample schema and tables below. Return both the query...
Compute capacity, staffing trade-offs, and break-even
This question evaluates capacity-planning, bottleneck identification, labor-cost trade-offs, contractor vs overtime comparisons, break-even computatio...
Debug and test a Python function in venv
Consider the Python snippet below. """ import math def accumulate(nums, start=0, cache={}): total = start for n in nums: if n % 2 == 0: nums.appen...
Decide whether to renew or sell a TV series
This question evaluates a data scientist's skills in financial valuation (NPV and LTV), causal inference and experimental design, sensitivity analysis...
Impute missing values without leakage
Given a DataFrame df with columns: user_id, event_date (datetime), country (categorical), device_type (categorical), age (numeric), income (numeric), ...
Merge seven tables into one clean DataFrame
Using pandas only (no loops over rows), write a function build_facts(customers, orders, order_items, products, payments, shipments, refunds) -> pd.Dat...
Design a reproducible data pipeline for modeling
You receive raw clickstream events and a user table. Build a reproducible daily pipeline that outputs user-day features for modeling. It must be idemp...
Impute, join, and upsert using SQL and Python
Write both SQL and Python (pandas) to complete the following data-manipulation tasks. Assume today is 2025-09-01 for any time filters. Schema: custome...
Fix dash dates and aggregate watch time
You receive a CSV of ad viewing logs where the date column repeats only on the first row of each block and subsequent rows use a single dash '-' to in...
Write one SQL for exam scores aggregation
You are given an exam database. Write a single SQL statement (CTEs allowed; one final statement only) that satisfies all three requirements below. You...
Calculate Year-1 profit margin
This question evaluates a candidate's ability to perform applied financial math, including profit margin calculation, classification of costs into fix...
Merge ad CSVs and compute CTR
Using SQL, clean and merge four CSVs and answer all parts exactly. Schema and sample rows (assume types: date is DATE, others INT/VARCHAR): platforms(...
Aggregate exam scores with NULL handling
Write a single SQL query (or CTE pipeline) to satisfy all requirements using the schema and sample data below. Replace any vendor-specific function wi...
Match prior-year profit with new fixed costs
This question evaluates cost–volume–profit analysis, unit economics, and algebraic modeling of fixed versus variable costs in a multi-product sales mi...
Identify and validate risky assumptions
This question evaluates experimental design, causal inference, and business-analytics competencies for a Data Scientist by testing the ability to iden...
Count ordered pairs that concatenate to target
Given a list of integers numbers and an integer target, count the number of ordered pairs (i, j) with i != j such that concatenating numbers[i] follow...