Cost Optimization for AI Document Pipelines on AWS (A Playbook)

Key Takeaways

• Cost optimi

AI document pipelines can get expensive fast if they are built like prototypes. This post covers practical levers to reduce cost without sacrificing reliability.

Cost drivers in document AI

• OCR cost per page
• Preprocessing compute
• Storage and retention
• Human review time
• Engineering time maintaining brittle scripts

Lever 1: Reduce pages before you pay for OCR

Common wins:

• Detect and drop blank pages
• Split large PDFs and process only relevant sections
• Use low cost heuristics to identify document type

Lever 2: Batch and parallelize intelligently

• Use asynchronous Textract for large PDFs
• Use Step Functions map states for safe parallelism

References:

• Textract async: https://docs.aws.amazon.com/textract/latest/dg/api-async.html
• Step Functions map state: https://docs.aws.amazon.com/step-functions/latest/dg/amazon-states-language-map-state.html

Lever 3: Confidence gating and selective review

Review time is often the largest hidden cost.

Implement:

• Required fields and thresholds
• Validation rules
• Auto approve when rules pass

Lever 4: Cache and dedupe

Many workflows reprocess the same doc.

Techniques:

• Hash raw content
• Store OCR results keyed by hash
• Avoid reruns unless the pipeline version changes

Lever 5: Use the right storage tier

• Use S3 lifecycle rules
• Store derived artifacts for a limited time

Reference:

• S3 lifecycle: https://docs.aws.amazon.com/AmazonS3/latest/userguide/object-lifecycle-mgmt.html

Lever 6: Pick the right database model

MongoDB is useful for workflow state and extracted records, but avoid storing large binaries in the database. Keep binaries in S3 and store pointers.

References:

• MongoDB GridFS: https://www.mongodb.com/docs/manual/core/gridfs/

zation is mostly about reducing waste before OCR and review.

• Batch work and use Step Functions for safe parallelism.
• Cache OCR outputs and dedupe reprocessing.
• Store binaries in S3, store metadata and structured records in MongoDB.

zion services: https://lidvizion.ai/

FAQs

Q: Is managed OCR always more expensive? Not necessarily. Managed services often reduce engineering and ops cost. You need to compare total cost of ownership.

Q: How do we estimate cost before building? Run a pilot on representative documents, measure page counts, exception rates, and review time, then extrapolate.

Q: What is a reasonable first metric to track? Track cost per processed document and percent routed to review.

Internal reference:

• Lid Vi

Q: What should we link to internally? A: Link to relevant solution pages like Computer Vision or Document Intelligence, and only link to published blog URLs on the main domain. Avoid staging links.