Architecture scenarioMedium~10 minData & APIs / 25 of 33

Interview question

How would you design soft delete in an EF Core-backed API, and what problems can it create?

Design a safe soft-delete strategy in EF Core APIs

Explains soft delete in EF Core APIs with practical .NET data-access examples and production trade-offs.

1Say itAnswer out loud first

2CompareCompare with Core answer

3RefineRefine with Stronger and Advanced

TL;DR

Soft delete means marking a row as deleted instead of physically removing it. For example, the table may have IsDeleted and DeletedAt columns. The API hides those records from normal queries, often with a global query filter. This helps with recovery and audit scenarios.

Full answer below

Practice focus

Understanding of soft delete in EF Core APIs, EF Core/SQL behavior, API boundaries, production risks, and practical debugging or design judgment.

Answer first

Answer path

Core answer first, then checkpoints toward a stronger answer.

Start
Core answer
Start here. This is the direct spoken answer to practice first.
Why this question matters
Explain soft delete in EF Core APIs with practical .NET data-access examples and production trade-offs. It matters in real backend work because query shape, indexes, transactions, locking, and data volume can turn harmless-looking code into a production bottleneck. The practical angle is soft delete in EF Core APIs, EF Core/SQL behavior, API boundaries, production risks, and practical debugging or design judgment, tied to a concrete production decision.
Soft delete means marking a row as deleted instead of physically removing it. For example, the table may have IsDeleted and DeletedAt columns. The API hides those records from normal queries, often with a global query filter. This helps with recovery and audit scenarios.
Checkpoint
Stronger answer
Optional upgrade with examples, trade-offs, and sharper phrasing.
Deleting a customer might set IsDeleted = true so support can restore it later. The trade-off is that every query, uniqueness rule, and report must understand deleted data. A unique email constraint may block a new customer if a deleted row still has the same email. I would design query filters, admin access, and database constraints deliberately.
Finish
Advanced answer
Optional deeper angle for production judgment and nuance.
I treat soft delete as a product and data-governance decision. It helps with recovery, audit, and accidental deletion, but it can conflict with privacy requirements, legal deletion, unique constraints, and performance. I make deletion semantics explicit: hidden from users, restorable by admins, retained for a policy period, or anonymized when required. I also test that soft-deleted records do not leak through joins, search, exports, or background jobs.

Coding practice

Practice the problem like a real interview: restate, reason, implement, and test.

ExampleCandidatePractical exampleWalk through sample input and output.Open details

Details

In EF Core, a global query filter can exclude IsDeleted rows, but admin queries may need IgnoreQueryFilters() carefully. That call should be deliberate and audited, not casually used everywhere.

Review signals

Use these to catch weak phrasing, shallow reasoning, and risky claims.

Common mistakesCandidateCommon mistakesMistakes that weaken the answer or signal shallow understanding.Open details

Details

Treating soft delete in EF Core APIs as a syntax detail instead of a production behavior.
Not checking generated SQL, query plans, or actual data volume.
Testing only with tiny local data and assuming production will behave the same.
Fixing symptoms with caching, timeouts, or retries before understanding the data-access cause.

Red flagsCandidateSigns the approach is fragileSignals that an interviewer may treat as risky.Open details

Details

Cannot explain how soft delete in EF Core APIs affects API behavior.
Gives only a definition with no practical example.
Ignores production failure modes.
Does not know how to verify the behavior.

Follow-up prompts

Quick interviewer prompts inside this drill.

Follow-up questionsCandidateFollow-up questionsLikely next questions after the main answer.Open details

Details

Treat these as the next interviewer turn. Answer one out loud, then save the gap in your practice notes.

How do global query filters support soft delete?
How do soft deletes affect unique indexes?
When is hard delete required?
How can soft-deleted data leak through reports?

Continue the section

Next in Data & APIs: Tenant Filtering

Step 26 of 33

Multi-tenant data filtering in EF Core APIs

Opening drill

Architecture scenarioMedium~10 minData & APIs / 25 of 33

Interview question

How would you design soft delete in an EF Core-backed API, and what problems can it create?

Design a safe soft-delete strategy in EF Core APIs

Explains soft delete in EF Core APIs with practical .NET data-access examples and production trade-offs.

1Say itAnswer out loud first

2CompareCompare with Core answer

3RefineRefine with Stronger and Advanced

TL;DR

Full answer below

Practice focus

Understanding of soft delete in EF Core APIs, EF Core/SQL behavior, API boundaries, production risks, and practical debugging or design judgment.

Answer first

Answer path

Core answer first, then checkpoints toward a stronger answer.

Start
Core answer
Start here. This is the direct spoken answer to practice first.
Why this question matters
Explain soft delete in EF Core APIs with practical .NET data-access examples and production trade-offs. It matters in real backend work because query shape, indexes, transactions, locking, and data volume can turn harmless-looking code into a production bottleneck. The practical angle is soft delete in EF Core APIs, EF Core/SQL behavior, API boundaries, production risks, and practical debugging or design judgment, tied to a concrete production decision.
Soft delete means marking a row as deleted instead of physically removing it. For example, the table may have IsDeleted and DeletedAt columns. The API hides those records from normal queries, often with a global query filter. This helps with recovery and audit scenarios.
Checkpoint
Stronger answer
Optional upgrade with examples, trade-offs, and sharper phrasing.
Deleting a customer might set IsDeleted = true so support can restore it later. The trade-off is that every query, uniqueness rule, and report must understand deleted data. A unique email constraint may block a new customer if a deleted row still has the same email. I would design query filters, admin access, and database constraints deliberately.
Finish
Advanced answer
Optional deeper angle for production judgment and nuance.
I treat soft delete as a product and data-governance decision. It helps with recovery, audit, and accidental deletion, but it can conflict with privacy requirements, legal deletion, unique constraints, and performance. I make deletion semantics explicit: hidden from users, restorable by admins, retained for a policy period, or anonymized when required. I also test that soft-deleted records do not leak through joins, search, exports, or background jobs.

Coding practice

Practice the problem like a real interview: restate, reason, implement, and test.

ExampleCandidatePractical exampleWalk through sample input and output.Open details

Details

In EF Core, a global query filter can exclude IsDeleted rows, but admin queries may need IgnoreQueryFilters() carefully. That call should be deliberate and audited, not casually used everywhere.

Review signals

Use these to catch weak phrasing, shallow reasoning, and risky claims.

Common mistakesCandidateCommon mistakesMistakes that weaken the answer or signal shallow understanding.Open details

Details

Treating soft delete in EF Core APIs as a syntax detail instead of a production behavior.
Not checking generated SQL, query plans, or actual data volume.
Testing only with tiny local data and assuming production will behave the same.
Fixing symptoms with caching, timeouts, or retries before understanding the data-access cause.

Red flagsCandidateSigns the approach is fragileSignals that an interviewer may treat as risky.Open details

Details

Cannot explain how soft delete in EF Core APIs affects API behavior.
Gives only a definition with no practical example.
Ignores production failure modes.
Does not know how to verify the behavior.

Follow-up prompts

Quick interviewer prompts inside this drill.

Follow-up questionsCandidateFollow-up questionsLikely next questions after the main answer.Open details

Details

Treat these as the next interviewer turn. Answer one out loud, then save the gap in your practice notes.

How do global query filters support soft delete?
How do soft deletes affect unique indexes?
When is hard delete required?
How can soft-deleted data leak through reports?

Continue the section

Next in Data & APIs: Tenant Filtering

Step 26 of 33

Multi-tenant data filtering in EF Core APIs

How would you design soft delete in an EF Core-backed API, and what problems can it create?

Practice focus

Answer path

Why this question matters

Coding practice

Review signals

Follow-up prompts

Continue the section

How would you design soft delete in an EF Core-backed API, and what problems can it create?

Practice focus

Answer path

Why this question matters

Coding practice

Review signals

Follow-up prompts

Continue the section