Dataford
Dataford
Top 37
Prep plan
Updated weekly · Last refresh Oct 17

Deel Backend Engineer Interview Questions

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

37questions
~5htotal time
Track your progressSign up free to work through all 37 questions and resume where you left off.
Start practicing free →
1
SQL & Data ManipulationStart here. 9 questions + 3 drills · ~102 min
Handling Deadlocks in Concurrent TransactionsMedium

Explain how to detect, prevent, and recover from deadlocks in concurrent PostgreSQL transaction workloads.

deadlocksdatabase managementmysqlDeel
SQL Performance and Schema DesignHard

Assesses your SQL tuning and schema design skills for backend performance.

indexingJoinsDeel
SQL Concurrency and LocksHard
Practice
Practice drill

Identify waiting PostgreSQL lock requests and the granted requests that block them.

deadlocksdatabase managementACIDDeel
Optimizing Slow SQL QueriesHard
Practice
Practice drill

Identify rolled-back or lock-waiting transactions and summarize their concurrency impact using aggregation and a left join.

deadlocksdatabase managementACIDDeel
Relational Database ExperienceMedium
Practice
Practice drill

Demonstrate relational database experience by summarizing qualifying contractor payments with joins, aggregation, and date filtering.

experienceJoinsrelational databasesDeel
More SQL & Data Manipulation questions with a free account
2
Coding5 questions · ~40 min
Home Assignment: Express and SequelizeHard

Evaluates your ability to implement REST endpoints with authentication-ready backend structure.

expressDeel
Home Exercise: 7 Sequelize EndpointsHard

Assesses practical backend implementation skills with ORM-based data access.

Deel
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
3
System Design7 questions · ~56 min
Designing a Detailed Data ModelHard

Evaluates your ability to design detailed data models and backend system interactions.

system designDeel
More System Design questions with a free account
4
Behavioral & Leadership13 questions · ~105 min
More Behavioral & Leadership questions with a free account
5
More topics3 questions · ~24 min
Locks and When to Use ThemMedium

Evaluates your concurrency control knowledge and practical locking trade-offs.

concurrencyDeel
Handling API ConcurrencyMedium

Assesses your approach to concurrency control, correctness, and performance in backend APIs.

concurrencyDeel
Maintainable Code for TeamsMedium

Tests your practices for writing clean, understandable, and well-documented frontend code at scale.

best practicescode maintainabilityDeel
The finish line: interview-readyComplete all 37 questions plus 3 hands-on drills to finish this plan.