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Architecture · Document intelligence

Architecture for document processing and AI extraction

Design secure document intake, OCR, structured extraction and reviewer workflows with field evidence, validation and recoverable processing.

Practical engineering guidance · Finance, operations and engineering teams planning invoice, form or document extraction workflows.
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Illustrative architecture workshop

At a glance

What you need to know.

Document processing turns a file into verified business information. This design separates secure intake, recognition, extraction and acceptance. Preserve original evidence and review uncertain fields before downstream changes. Begin with a defined document family and schema, then evaluate layout, scan quality and business exceptions.

How the system fits together.

A reference flow to adapt to your data, users and operating constraints.

  1. 01

    Receive and quarantine

    Authorize the upload, validate supported types and keep the file in restricted storage.

  2. 02

    Inspect and prepare

    Apply safety checks and processing limits before rendering pages or extracting text.

  3. 03

    Recognize the content

    Read text, tables and page coordinates while preserving the original document reference.

  4. 04

    Extract structured fields

    Map relevant content into a versioned schema with evidence locations for important values.

  5. 05

    Validate and review

    Check business rules, duplicates and uncertain fields using a reviewer interface.

  6. 06

    Commit and reconcile

    Publish accepted data through an authorized integration and retain its receipt.

Treat files as untrusted input from the beginning

Limit intake to document formats needed by the workflow. Validate more than the supplied extension or Content-Type, generate the stored filename and enforce file, page and processing limits. Keep uploads outside public application paths, authorize downloads and restrict the parser’s environment. Malicious or malformed documents can target rendering and extraction libraries. Scanning helps, but no single check makes every file safe.

An illustrative accounts-payable workflow accepts supported invoice documents into a quarantine area, then creates a processing job with a stable identifier. The upload receipt tells the user that intake succeeded; it does not claim the invoice was accepted. A document that cannot be processed remains visible with a specific exception reason. Do not repeatedly parse the same unsupported file without a change that could resolve the problem.

Preserve the connection between fields and their source

Store the original file reference, document hash, processing version and extracted output. Important fields should include page or region evidence where the extractor can provide it. Distinguish recognized text from a normalized value and from a value corrected by a reviewer. This lets the reviewer examine a supplier name, invoice number or tax amount without searching the entire document and preserves the reason behind the final accepted record.

Choose between template rules, OCR, document models and language models using the actual document family. Templates can work well for stable layouts; varied scans and tables may need more flexible recognition. A language model can help map content into a schema, but plausible output is not proof that a field exists. Treat instructions inside a document as untrusted data and forbid them from controlling the processing application.

Apply domain rules before changing a system of record

Validate required fields, dates, currencies and arithmetic under the relevant business rules. Check candidate supplier identifiers against permitted records and detect likely duplicate documents using more than a filename. A valid schema does not establish that an invoice belongs to the requester’s organization or that payment is approved. Keep extraction, invoice acceptance and payment authorization as separate decisions with distinct permissions.

Route missing, inconsistent or ambiguous fields to a reviewer with the source evidence and permitted correction controls. Track corrections as new decisions, not silent edits to the extraction history. Send only accepted values to the downstream system. Integration jobs need idempotency and reconciliation because message delivery or a timeout may repeat a write. Expose a pending or uncertain outcome until the external receipt is confirmed.

Evaluate fields and complete documents separately

Build a reviewed sample covering layouts, languages, scan quality, rotated pages, multi-page tables and missing values relevant to the workflow. Measure field correctness and document-level acceptance separately. A document with many correct fields can still be unsafe to accept when a critical amount is wrong. Evaluate routing into review as well as extraction accuracy, including how often a reviewer must correct an automatically accepted field.

Test oversized input, parser failure, a model outage, duplicate upload and a restart during processing. Agree processing time, retention, review workload and integration acceptance criteria before rollout. More review can improve assurance while increasing operational effort; broader format support creates a larger evaluation and security burden. Start with the supported document types that can be assessed reliably, and provide an explicit manual route for the rest.

Before you start.

  • Define supported formats, limits and private storage.
  • Preserve originals, field evidence and processing versions.
  • Separate extraction from business approval and downstream writes.
  • Evaluate critical fields, review routing and duplicate recovery.

Common questions.

Does OCR provide the final business data?

OCR recognizes text. A complete workflow still needs field mapping, normalization, business validation, review where needed and an authorized downstream integration.

Can extracted invoices be paid automatically?

Extraction alone does not establish payment authority. Invoice acceptance, supplier validation and payment approval need their own policies, permissions and evidence before execution.

Continue with the right next step.

Technical references

Map this to your workflow.

Bring the users, existing systems, data boundaries and success criteria. We can discuss the scope and the engineering decisions that need evidence.

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