Concept questionMedium~7 min

Interview question

How would you connect an App Service-hosted .NET API to Azure SQL without storing a SQL password?

How would a .NET API connect to Azure SQL without a password?

Covers using managed identity and Microsoft Entra authentication for Azure SQL access from a .NET API.

1Say itAnswer out loud first

2CompareCompare with Core answer

3RefineRefine with Stronger and Advanced

TL;DR

I would enable managed identity for the App Service, create a database user for that identity in Azure SQL, and grant only the permissions the API needs. In the connection string I would use Microsoft Entra authentication for managed identity rather than a SQL username and password. The .NET code still uses normal SQL client or EF Core patterns, but authentication comes from the platform identity instead of a stored secret.

Full answer below

Practice focus

Managed identity, Azure SQL permissions, connection strings, EF Core integration, local development differences, and least privilege.

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
Managed identity lets an App Service authenticate to Azure SQL without carrying a database password. The Azure identity, database user mapping, least-privilege grants, and network path must all line up before the connection succeeds.
I would enable managed identity for the App Service, create a database user for that identity in Azure SQL, and grant only the permissions the API needs. In the connection string I would use Microsoft Entra authentication for managed identity rather than a SQL username and password. The .NET code still uses normal SQL client or EF Core patterns, but authentication comes from the platform identity instead of a stored secret.
Checkpoint
Stronger answer
Optional upgrade with examples, trade-offs, and sharper phrasing.
I would separate three steps: assign the app identity, grant it access in Azure SQL, and configure the connection string correctly. The app identity is not automatically a database user just because it exists in Azure. I would grant least privilege, usually to an application role or specific schema permissions, and test migrations separately from runtime access. Local development may use a developer identity, local secret, or test database, but that does not change the production rule: the deployed app does not need a password to reach Azure SQL.
Finish
Advanced answer
Optional deeper angle for production judgment and nuance.
In production I would treat this as both security and operability. Managed identity removes secret rotation work, but permissions still need review, audit, and environment separation. I would avoid using the same identity across unrelated apps if it blurs ownership. I would verify connection pooling, transient fault handling, and EF Core execution strategies because authentication is only one part of database reliability. During incidents, I would check identity assignment, SQL user mapping, firewall or private endpoint access, token acquisition, and permission changes before blaming application code.

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

Assuming managed identity automatically creates database permissions.
Granting database owner because least privilege takes longer.
Using the same production identity in staging without a clear reason.
Ignoring local development authentication and migration permissions.

Red flagsCandidateRed flagsSignals that an interviewer may treat as risky.Open details

Details

Cannot explain how Azure SQL recognizes the app identity.
Still stores a SQL password in App Service settings without justification.
No distinction between runtime access and migration/admin access.
Does not mention least privilege or environment separation.

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.

Where would you grant the app identity database access?
How would local development connect?
Would migrations use the same identity as runtime?
What would you check if login suddenly started failing?

Continue practice

No explicit flow link is set yet, so these are nearby drills from the same path or taxonomy.

Abstraction vs encapsulationConcept question / Easy / ~5 minContinue Access modifiersConcept question / Easy / ~5 minContinue ActionResult vs Typed ResultsComparison question / Medium / ~7 minContinue

Opening drill

Concept questionMedium~7 min

Interview question

How would you connect an App Service-hosted .NET API to Azure SQL without storing a SQL password?

How would a .NET API connect to Azure SQL without a password?

Covers using managed identity and Microsoft Entra authentication for Azure SQL access from a .NET API.

1Say itAnswer out loud first

2CompareCompare with Core answer

3RefineRefine with Stronger and Advanced

TL;DR

Full answer below

Practice focus

Managed identity, Azure SQL permissions, connection strings, EF Core integration, local development differences, and least privilege.

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
Managed identity lets an App Service authenticate to Azure SQL without carrying a database password. The Azure identity, database user mapping, least-privilege grants, and network path must all line up before the connection succeeds.
I would enable managed identity for the App Service, create a database user for that identity in Azure SQL, and grant only the permissions the API needs. In the connection string I would use Microsoft Entra authentication for managed identity rather than a SQL username and password. The .NET code still uses normal SQL client or EF Core patterns, but authentication comes from the platform identity instead of a stored secret.
Checkpoint
Stronger answer
Optional upgrade with examples, trade-offs, and sharper phrasing.
I would separate three steps: assign the app identity, grant it access in Azure SQL, and configure the connection string correctly. The app identity is not automatically a database user just because it exists in Azure. I would grant least privilege, usually to an application role or specific schema permissions, and test migrations separately from runtime access. Local development may use a developer identity, local secret, or test database, but that does not change the production rule: the deployed app does not need a password to reach Azure SQL.
Finish
Advanced answer
Optional deeper angle for production judgment and nuance.
In production I would treat this as both security and operability. Managed identity removes secret rotation work, but permissions still need review, audit, and environment separation. I would avoid using the same identity across unrelated apps if it blurs ownership. I would verify connection pooling, transient fault handling, and EF Core execution strategies because authentication is only one part of database reliability. During incidents, I would check identity assignment, SQL user mapping, firewall or private endpoint access, token acquisition, and permission changes before blaming application code.

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

Assuming managed identity automatically creates database permissions.
Granting database owner because least privilege takes longer.
Using the same production identity in staging without a clear reason.
Ignoring local development authentication and migration permissions.

Red flagsCandidateRed flagsSignals that an interviewer may treat as risky.Open details

Details

Cannot explain how Azure SQL recognizes the app identity.
Still stores a SQL password in App Service settings without justification.
No distinction between runtime access and migration/admin access.
Does not mention least privilege or environment separation.

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.

Where would you grant the app identity database access?
How would local development connect?
Would migrations use the same identity as runtime?
What would you check if login suddenly started failing?

Continue practice

No explicit flow link is set yet, so these are nearby drills from the same path or taxonomy.

How would you connect an App Service-hosted .NET API to Azure SQL without storing a SQL password?

Practice focus

Answer path

Why this question matters

Review signals

Follow-up prompts

Continue practice

How would you connect an App Service-hosted .NET API to Azure SQL without storing a SQL password?

Practice focus

Answer path

Why this question matters

Review signals

Follow-up prompts

Continue practice