Top 50

Prep plan

Updated weekly · Last refresh Oct 17

Unknowns Software Engineer Interview Questions

The questions to prepare for a Unknowns Software Engineer interview. Questions from real interview reports rank first. Updated daily.

50questions

~8htotal time

Track your progressSign up free to work through all 50 questions and resume where you left off.

Start practicing free →

SQL & Data ManipulationStart here. 14 questions + 2 drills · ~151 min

Second Highest Trader SalaryEasy

Practice

Find the second highest distinct salary from a single table using basic PostgreSQL ordering and limiting.

SubqueriesRankingSorting

Unknowns

Explain SQL Join TypesEasy

Explain INNER, LEFT, RIGHT, FULL OUTER, CROSS, and SELF JOINs with examples and when to use each.

JoinsData WranglingGroup By

Unknowns

SQL Query for Customer DataEasy

Practice

Practice drill

Extract selected customer fields from Unknowns' customer table and return them in customer ID order.

JoinsData Wranglingdatabase querying

Unknowns

SQL Query for Data ExtractionEasy

Practice

Practice drill

Extract qualifying market observations by venue and price, then return them in chronological order.

JoinsData ManipulationGroup By

Equifax

DPR Construction

RigUp

More SQL & Data Manipulation questions with a free account

Coding14 questions · ~131 min

Longest Substring Without RepeatsMedium

Practice

Find the longest substring with all unique characters using a sliding window.

Hash TablesStringsTwo Pointers

Unknowns

Linked List ReversalEasy

Practice

Reverse a singly linked list in-place using iterative pointer manipulation.

RecursionLinked ListsArrays

Unknowns

More Coding questions with a free account

Sign up to see every question

Create a free account to unlock this list and practice real interview questions.

Get my prep plan

Execution5 questions · ~47 min

Your Strengths and WeaknessesEasy

Give a specific, self-aware account of your strengths and weaknesses, supported by relevant examples and improvement actions.

Trade-offsSuccess CriteriaExecution

Unknowns

More Execution questions with a free account

System Design4 questions · ~37 min

Distributed Systems BasicsMedium

Assesses understanding of distributed systems concepts and tradeoffs.

distributed systems

Unknowns

More System Design questions with a free account

Security & Infrastructure8 questions · ~75 min

Communication Protocols BasicsMedium

Evaluates your foundational networking knowledge at the protocol level.

Networkingprotocols

Unknowns

More Security & Infrastructure questions with a free account

Behavioral & Leadership4 questions · ~37 min

More Behavioral & Leadership questions with a free account