SAP-C02 Design for New Solutions Practice Question

A media company runs a video processing pipeline on AWS. Videos are uploaded to an S3 bucket, which triggers an AWS Lambda function that transcodes the video into multiple formats using FFmpeg. The transcoding job runs on the Lambda function with a 15-minute timeout. Recently, the company started receiving 4K videos that take more than 15 minutes to transcode. The Lambda function times out, and the video is not processed. The company wants to process these large videos without increasing the Lambda timeout and without rewriting the entire pipeline. What should the solutions architect do?

⚠ Common exam trap

SAP-C02 often tests whether candidates recognize that Lambda's 15-minute timeout is a hard, non-negotiable limit — tempting them to 'just add memory' or 'add storage' when the real fix is moving long-running work to a purpose-built service like MediaConvert, Fargate, or Batch.

Answer choices

Why each option matters

Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.

Correct answer & explanation

✓

Replace the Lambda function with AWS Elemental MediaConvert job triggered by S3 events.

AWS Elemental MediaConvert is a managed, file-based video transcoding service designed for large-scale, long-running jobs that far exceed Lambda's 15-minute execution limit. It natively integrates with S3 (input/output buckets) and can be triggered by S3 event notifications via EventBridge or Lambda, so the existing upload-to-S3 pipeline is preserved with minimal changes. This directly solves the 4K transcoding timeout without increasing Lambda timeout or rewriting the pipeline.

Answer analysis

Option-by-option breakdown

For each option: why learners choose it and why it is or isn't the right answer here.

✓
Replace the Lambda function with AWS Elemental MediaConvert job triggered by S3 events.
Why this is correct
MediaConvert is a managed transcoding service handling large 4K files without Lambda's 15-minute limit. Triggering jobs from existing S3 events preserves the pipeline's entry point, so only the compute layer changes, satisfying the requirement to avoid rewriting the pipeline.
✗
Increase the Lambda function memory to the maximum to improve performance and reduce processing time.
Why it's wrong here
Memory size affects CPU allocation and speed, but transcoding 4K video beyond 15 minutes cannot be guaranteed within Lambda's hard timeout, so the job still fails. It is tempting because memory tuning often speeds up Lambda, and it would be correct for a CPU-bound function that finishes comfortably within the limit.
✗
Use AWS Step Functions to call multiple Lambda functions in parallel to process chunks of the video.
Why it's wrong here
Chunking a single video across parallel Lambda invocations requires splitting and reassembling the file, effectively rewriting the pipeline, and FFmpeg transcoding is not safely parallelisable this way. Step Functions orchestration suits multi-step workflows, not extending one long-running transcode.
✗
Use a Lambda function with a larger ephemeral storage to handle the video file.
Why it's wrong here
Ephemeral storage capacity does not extend the 15-minute Lambda invocation limit, so the transcode still times out. It is tempting because larger /tmp storage helps functions that exhaust disk space, which would be the correct fix if the failure were a storage error rather than a timeout.

Quick reference

AWS S3 Storage Class Comparison

Storage Class	Min Duration	Retrieval	Use Case
S3 Standard	None	Immediate	Frequently accessed data
S3 Standard-IA	30 days	Immediate	Infrequent access, rapid retrieval
S3 One Zone-IA	30 days	Immediate	Non-critical infrequent data
S3 Intelligent-Tiering	None	Immediate–hours	Unknown or changing access patterns
S3 Glacier Instant	90 days	Milliseconds	Archive with instant retrieval
S3 Glacier Flexible	90 days	Minutes–hours	Archive, flexible retrieval
S3 Glacier Deep Archive	180 days	Hours	Long-term compliance archive

Go deeper

SAP-C02 Design for New Solutions Practice Question

Why each option matters

Option-by-option breakdown

AWS S3 Storage Class Comparison

Related to this question