Dataford
Top 50
Company roadmap
Updated weekly · Last refresh Sep 24

Programming Interview Questions

The questions to prepare for Programming interviews, across all roles. Questions from real interview reports rank first. Updated daily.

50questions
~7htotal time
Track your progressSign up free to work through all 50 questions and resume where you left off.
Start practicing free →
1
CodingStart here. 8 questions · ~68 min
Flatten Nested DataHard
Practice

Flatten nested dictionaries and arrays into dot-delimited paths using iterative depth-first traversal.

Data StructuresArray ManipulationProgramming
More Coding questions with a free account
2
Execution8 questions · ~68 min
Decide What to AutomateEasy

Explain how you decide which tests to automate versus keep manual, balancing risk, cost, and long-term maintenance.

Trade-offsRisk AssessmentScope ManagementProgramming
More Execution 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
Pipelines7 questions · ~60 min
Tune SQL in Data PipelinesMedium

A practical approach to tuning slow SQL queries and stored procedures used inside data pipelines.

sql tuningstored proceduresperformanceProgramming
More Pipelines questions with a free account
4
System Design7 questions · ~60 min
SSR vs CSR TradeoffsMedium

Assesses ability to choose rendering strategies based on product constraints.

performanceProgramming
More System Design questions with a free account
5
SQL & Data Manipulation3 questions + 3 drills · ~56 min
SQL Joins vs Stored ProceduresMedium
Recently asked

Evaluates your ability to choose the right data access strategy for correctness, performance, and maintainability.

stored proceduresdatabase conceptsProgramming
Indexes and Performance TradeoffsMedium
Practice
Practice drill

Classify clinical-data indexes by read usage and estimated write-maintenance overhead.

database optimizationdatabase managementperformanceMedpace
Optimize SQL QueriesMedium
Practice
Practice drill

Optimize a PostgreSQL aggregation query by filtering early, reducing rows before joins, and returning qualifying active customers.

database optimizationperformanceindexesSofteamSSoftware Medical InformaticsGlassdoor
PostgreSQL Indexing Trade-OffsHard
Practice
Practice drill

Evaluate PostgreSQL index choices for a filtered asset query and explain read, write, storage, and maintenance trade-offs.

postgresqldatabase optimizationindexingAdobe
More SQL & Data Manipulation questions with a free account
6
Security & Infrastructure3 questions · ~26 min
Debugging Production Memory LeaksHard
Recently asked

Tests your troubleshooting process for diagnosing memory leaks and validating fixes under production constraints.

memory leakDebuggingproductionProgramming
More Security & Infrastructure questions with a free account
7
More topics14 questions · ~120 min
Define Success for a ProjectEasy

Define what success means for a project using clear KPIs, a north star, and supporting metrics.

KPIsSuccess CriteriaDiagnosisProgramming
Automation Testing ConceptsMedium

Assesses understanding of automation testing concepts and decision-making for automation.

Programming
More questions with a free account
The finish line: interview-readyComplete all 50 questions plus 3 hands-on drills to finish this plan.