The correct answer is the JWT authorizer configured for the OpenID Connect issuer. This mechanism directly validates standards-based tokens from an external OIDC provider by verifying the JWT’s signature against the provider’s JWKS endpoint, checking the `iss` and `aud` claims, and enforcing expiration—all without custom code. On the SAA-C03 exam, this scenario tests your understanding of when to use a managed authorizer versus a Lambda authorizer; a common trap is choosing a Lambda authorizer for OIDC tokens, which adds unnecessary complexity and cost. Remember that API Gateway’s JWT authorizer natively supports OIDC discovery, so if the question mentions an external OpenID Connect provider and standards-based JWTs, the JWT authorizer is the direct, infrastructure-free solution. A useful memory tip: “JWT for OIDC, Lambda for custom logic”—if the token format and issuer are standard, let the gateway handle validation.
SAA-C03 Design Secure Architectures Practice Question
This SAA-C03 practice question tests your understanding of design secure architectures. Read the scenario carefully and evaluate each option against the stated constraints before committing to an answer. After answering, compare your reasoning against the explanation and wrong-answer breakdown below. Once you have made your selection, read the full explanation to reinforce the concept and understand why each distractor is designed to mislead on exam day.
A public API for a customer analytics portal is deployed on API Gateway. Clients must authenticate with standards-based tokens issued by an external OpenID Connect provider. Which authorization mechanism should be used?
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
JWT authorizer configured for the OpenID Connect issuer
Option B is correct because the scenario requires standards-based token authentication from an external OpenID Connect (OIDC) provider. API Gateway's JWT authorizer natively validates JSON Web Tokens (JWTs) issued by OIDC providers by verifying the token's signature against the provider's JWKS endpoint, checking the `iss` and `aud` claims, and enforcing token expiration. This directly meets the requirement without needing custom Lambda authorizers or additional infrastructure.
Key principle: Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
✗
API keys only
Why it's wrong here
API keys identify clients for usage plans but do not authenticate users securely.
✓
JWT authorizer configured for the OpenID Connect issuer
Why this is correct
A JWT authorizer validates tokens from a trusted OIDC issuer with low operational overhead.
Related concept
Read the scenario before looking for a memorised answer.
✗
IAM authorization for all internet users
Why it's wrong here
IAM authorization is suited to AWS principals, not general OIDC-authenticated application users.
✗
A VPC endpoint policy
Why it's wrong here
Endpoint policies restrict private endpoint use, not public API user authentication.
Common exam traps
Common exam trap: answer the scenario, not the keyword
The trap here is that candidates confuse API keys (which are static and not standards-based) with JWT tokens (which are cryptographically signed and verifiable), or assume IAM authorization can be used for external identities without understanding that IAM requires AWS credentials, not OIDC tokens.
Detailed technical explanation
How to think about this question
The JWT authorizer in API Gateway performs token validation by fetching the OIDC provider's JWKS (JSON Web Key Set) URI to obtain public keys, then cryptographically verifying the JWT's RSA or ECDSA signature. It also enforces token expiry (`exp` claim) and optionally validates the `aud` (audience) claim to prevent token reuse across different APIs. In a real-world scenario, if the OIDC provider rotates its signing keys, API Gateway automatically caches the JWKS for up to 300 seconds by default, which can cause a brief window of failed authentication until the cache refreshes.
KKey Concepts to Remember
Read the scenario before looking for a memorised answer.
Find the constraint that changes the correct option.
Eliminate answers that are true in general but not in this case.
TExam Day Tips
→Watch for words such as best, first, most likely and least administrative effort.
→Review why wrong options are wrong, not only why the correct option is correct.
Key takeaway
Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Real-world example
How this comes up in practice
A company's IT admin needs to give a contractor read-only access to production logs without sharing account credentials. Using role-based access control (RBAC) and temporary scoped permissions — not a permanent shared password — is the correct pattern. Questions like this test whether you can apply least-privilege access across cloud identity services.
What to study next
Got this wrong? Here's your next step.
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
Design Secure Architectures — This question tests Design Secure Architectures — Read the scenario before looking for a memorised answer..
What is the correct answer to this question?
The correct answer is: JWT authorizer configured for the OpenID Connect issuer — Option B is correct because the scenario requires standards-based token authentication from an external OpenID Connect (OIDC) provider. API Gateway's JWT authorizer natively validates JSON Web Tokens (JWTs) issued by OIDC providers by verifying the token's signature against the provider's JWKS endpoint, checking the `iss` and `aud` claims, and enforcing token expiration. This directly meets the requirement without needing custom Lambda authorizers or additional infrastructure.
What should I do if I get this SAA-C03 question wrong?
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
What is the key concept behind this question?
Read the scenario before looking for a memorised answer.
About these practice questions
Courseiva creates original exam-style practice questions with explanations and wrong-answer analysis. It does not publish real exam questions, exam dumps, or protected exam content. Learn why practice questions differ from exam dumps →
These questions test the same concept from different angles. Work through them to make sure you can recognise it however the exam phrases it.
Variation 1. A public API for a customer analytics portal is deployed on API Gateway. Clients must authenticate with standards-based tokens issued by an external OpenID Connect provider. Which authorization mechanism should be used? The design must avoid adding custom operational scripts.
medium
A.API keys only
✓ B.JWT authorizer configured for the OpenID Connect issuer
C.IAM authorization for all internet users
D.A VPC endpoint policy
Why B: Option B is correct because a JWT authorizer in API Gateway can validate tokens issued by an external OpenID Connect (OIDC) provider without requiring custom code. The JWT authorizer automatically verifies the token's signature, expiry, and issuer against the OIDC provider's JWKS endpoint, meeting the requirement for standards-based authentication and avoiding custom operational scripts.
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This SAA-C03 practice question is part of Courseiva's free Amazon Web Services certification practice question bank. Courseiva provides original exam-style practice questions with explanations, topic-based practice, mock exams, readiness tracking, and study analytics to help learners prepare for the SAA-C03 exam.
Question Discussion
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