02 / How it comes together
The system,
in motion.
Financial documents mix tables, figures and narrative across many pages. Extracting an answer is only part of the work: reviewers also need to find its source, check its meaning and correct it within a dependable application workflow.
From source material to a result someone can verify.
Select a stage to explore.
Page-level references connect reviewed results back to the original evidence.
Document evidence
Tables, figures and narrative passages need to stay connected to their source. The review interface supports document upload and processing, with navigation back to the original evidence.
- Source documents
- Page references
This animation illustrates the flow; it is not live system activity.
03 / The thinking behind it
Good systems
start with
good decisions.
The choices that shape how this system works.
Find meaning. Keep the exact match.
Semantic search finds related passages; keyword search preserves exact terms and identifiers. Reciprocal Rank Fusion combines both rankings, giving extraction workflows relevant evidence without sending an entire document to the model for every operation.
Keep the evidence within reach.
Structured validation and citation checks support the AI output. In the review interface, page references and highlighted source passages let people inspect the evidence, correct extracted values and decide what to use.
Give processing its own workflow.
LangGraph coordinates retrieval, extraction and validation. Background workers, token-aware batches and Azure messaging separate long-running processing from immediate application requests, while retries and model routing support recoverable failures and evolving model choices.
04 / Under the surface
A closer look.
Explore the technologies, implementation choices, and full project context at your own pace.
Python · FastAPI · LangGraph · Azure AI Search
Angular 20 · TypeScript · Nx · NgRx Signals
C# · .NET · ASP.NET Core · REST APIs
Microsoft Foundry · Azure Service Bus · Azure Functions
01Executive Summary
PwC's DocIntelligence project involved developing an enterprise AI-powered platform designed to automate the extraction, analysis, and review of complex financial and business documents.
The solution combines Large Language Models (LLMs), Retrieval-Augmented Generation (RAG), agentic workflows, and cloud-native application services to support document processing at enterprise scale.
A central engineering challenge was moving beyond simple LLM interactions to create a reliable system capable of producing structured, evidence-grounded outputs that users could verify against original documents.
The platform brings together Python-based AI services, .NET backend APIs, an Angular frontend, and Microsoft Azure infrastructure.
Core value proposition: Transform complex, document-intensive workflows into AI-assisted processes with structured extraction, source traceability, automated validation, and human oversight.
02Business Challenge
Financial document analysis presents several challenges for enterprise organizations.
Complex and inconsistent document structures
Business and financial documents often contain tables, numerical data, narrative descriptions, and information distributed across multiple pages. Relevant information can appear in different locations and formats.
Time-consuming manual review
Identifying and extracting relevant information requires substantial manual effort, particularly when documents are lengthy or contain numerous financial details.
Accuracy and traceability
Conventional LLM responses can contain inaccurate values or conclusions that are not supported by the source material. Financial document processing requires mechanisms for verifying extracted information.
Enterprise processing requirements
Large-scale workflows need reliable asynchronous execution, fault tolerance, monitoring, and integration with existing applications.
Human validation
AI-generated outputs must remain accessible for human review, correction, and verification before being used in business processes.
03Solution Architecture
The platform follows a distributed architecture separating the user interface, application services, AI processing, and cloud infrastructure.
Frontend – Enterprise Document Review
Angular 20 · Nx · NgRx Signals · TypeScript
The frontend provides a unified interface for document upload, processing, extraction review, and evidence verification.
Key capabilities include:
- Document upload and processing workflows.
- AI-assisted review of extracted information.
- Source highlighting and evidence navigation.
- Structured data inspection and export.
- Prompt-authoring functionality.
- Integration with backend and AI processing services.
Backend – Enterprise Application Services
C# · .NET · REST APIs · Azure Service Bus
The .NET backend provides the application integration layer between the frontend, data persistence, and AI services.
Responsibilities include coordinating document operations, handling application requests, integrating AI processing workflows, and communicating with asynchronous processing components.
AI Processing Layer
Python · FastAPI · LangGraph · LLMs
The AI processing layer implements document extraction, information retrieval, workflow orchestration, and result validation.
Its responsibilities include:
- Retrieval of relevant document evidence.
- Structured information extraction.
- Multi-step agentic processing workflows.
- LLM model selection and routing.
- Token-aware batching.
- Output validation.
- Error handling, retries, and failover.
- Asynchronous processing.
Cloud Infrastructure
Microsoft Azure · Azure AI Search · Microsoft Foundry · Azure Functions
Azure services support retrieval, model integration, messaging, and background processing.
The architecture provides a foundation for separating computationally intensive AI workloads from user-facing application services.
04Hybrid Retrieval-Augmented Generation
One of the platform's core technical capabilities is its Hybrid RAG implementation.
Rather than providing complete documents directly to an LLM for every operation, the system retrieves relevant source evidence and supplies it to the model during extraction and review workflows.
Dense Retrieval
Semantic vector search identifies passages based on conceptual similarity between a query and document content.
This is valuable when the terminology used in a query differs from the wording found in the original document.
Sparse Retrieval
Keyword-oriented retrieval identifies passages based on lexical matching.
It is particularly useful for exact financial terminology, identifiers, and specific references.
Reciprocal Rank Fusion (RRF)
Results from dense and sparse retrieval are combined through Reciprocal Rank Fusion.
This produces a consolidated ranking that benefits from both semantic and lexical search.
Evidence-Grounded Extraction
Relevant source passages are supplied to the LLM as supporting context for extraction.
Generated results are associated with references to source evidence, supporting subsequent validation and review.
Page-Level Traceability
The platform provides page-level source references, enabling users to navigate from extracted information to the corresponding document evidence.
Technical outcome: A retrieval architecture designed to improve evidence discovery while supporting verifiable AI-generated results.
05Agentic Workflows & LLM Orchestration
The platform uses LangGraph-based workflows to coordinate multi-step AI operations.
Instead of relying on isolated LLM requests, the processing layer executes structured sequences of retrieval, extraction, and validation steps.
Workflow Capabilities
Document processing
Preparation and orchestration of document extraction tasks.
Evidence retrieval
Identification of relevant passages through hybrid search.
LLM extraction
Generation of structured information using retrieved document context.
Validation
Verification of output structure, citations, and consistency with source material.
Resilience
Retry and failover mechanisms for recoverable processing failures.
Multi-Model Routing
The architecture supports selecting different configured AI models depending on processing requirements.
This allows model capabilities to be evaluated and compared without tightly coupling the application to a single model.
Token-Aware Batching
Large inputs are divided into manageable processing batches that respect model context constraints.
This supports efficient processing of lengthy documents.
Asynchronous Execution
Background workers execute document processing operations independently of immediate frontend requests.
Azure messaging and serverless services support coordination across application components.
06AI Reliability, Evaluation & Guardrails
A key aspect of the engineering work was implementing mechanisms to evaluate and validate AI-generated outputs.
Ground-Truth Evaluation
Reference datasets containing expected extraction results are used to evaluate model performance.
Predictions can be compared against known values to identify errors and assess extraction quality.
Model Comparison
Different models and processing strategies can be evaluated against consistent reference datasets.
This supports evidence-based model selection and ongoing improvements.
Structured Output Validation
LLM responses are validated against expected data structures.
The objective is to prevent malformed or incomplete outputs from passing through downstream workflows.
Citation Accuracy
Source-reference validation mechanisms check whether extracted information is supported by the cited document evidence.
Consistency Checks
AI-generated information is assessed for inconsistencies against the original source documents.
Observability
Internally developed monitoring and evaluation mechanisms support investigation of model behavior, processing failures, and quality issues.
Engineering principle: LLM output is treated as information requiring validation, not as an inherently reliable source of truth.
07Human-in-the-Loop Document Review
The platform combines automated extraction with a user-facing review workflow.
Users can:
- Inspect extracted values.
- Examine source citations.
- Navigate to highlighted evidence.
- Review and correct AI-generated information.
- Work with structured results.
- Export processed information.
The system is designed to support human judgment rather than replace it.
This is particularly important for financial information, where traceability and correctness are essential.
08Enterprise Integration & Cloud Engineering
The platform integrates multiple application and AI technologies into a coordinated processing system.
Python/FastAPI
Dedicated services for AI operations, document extraction, retrieval, and workflow execution.
C#/.NET
Enterprise APIs and application integration services.
Azure Service Bus
Asynchronous messaging between processing and application components.
Azure Functions
Background and event-driven processing integrations.
Azure AI Search
Search infrastructure supporting hybrid retrieval.
Microsoft Foundry
Integration with AI model capabilities and associated platform services.
Angular
Enterprise user experience for document submission, evidence inspection, and AI-assisted review.
This separation allows AI processing capabilities to evolve independently from the application interface and conventional business services.
09Engineering Contributions
The engagement included hands-on contributions across several technical areas.
| Area | Contributions |
|---|---|
| AI Engineering | Python/FastAPI AI services, LangGraph workflows, LLM integration |
| Information Retrieval | Hybrid RAG, dense and sparse search, Reciprocal Rank Fusion |
| LLM Orchestration | Multi-model routing, token-aware batching, retries and failover |
| AI Reliability | Ground-truth evaluation, output validation, citation and consistency checks |
| Backend | C#/.NET APIs and enterprise integrations |
| Frontend | Angular document review, source highlighting, data export, prompt authoring |
| Cloud | Azure AI Search, Microsoft Foundry, Azure Service Bus, Azure Functions |
The engineering work combined AI-specific development with full-stack enterprise application integration.
10Business Value
The platform delivers capabilities intended to improve document-intensive enterprise workflows.
Faster Information Extraction
Automated document processing reduces reliance on manual identification and transcription of relevant information.
Evidence-Based AI Results
Source citations and document highlighting allow users to verify outputs against original materials.
Improved Review Experience
A unified review interface combines extracted information with relevant source evidence.
More Reliable AI Processing
Evaluation, validation, and resilient processing mechanisms address common limitations of conventional LLM-based applications.
Scalable Processing Architecture
Asynchronous workloads, batching, and Azure integrations support the processing demands of enterprise applications.
Long-Term Model Flexibility
The orchestration layer supports evaluating alternative models and adapting the AI processing strategy over time.
These describe implemented capabilities and intended business value. Quantified productivity improvements, accuracy rates, processing volumes, and financial returns are not claimed.
11Technology Stack
| Category | Technologies |
|---|---|
| AI & Orchestration | Python, FastAPI, LangGraph, LLMs |
| Retrieval | Hybrid RAG, Dense/Sparse Retrieval, RRF |
| AI Quality | Ground-Truth Evaluation, Guardrails, Structured Validation, Citation Checks |
| Backend | C#, .NET, ASP.NET Core, REST APIs |
| Frontend | Angular 20, Nx, NgRx Signals, TypeScript |
| Cloud & AI Services | Microsoft Azure, Microsoft Foundry, Azure AI Search |
| Messaging & Processing | Azure Service Bus, Azure Functions, Asynchronous Workers |
| Architecture | Distributed Services, Agentic Workflows, Human-in-the-Loop |
12Key Takeaways
The DocIntelligence engagement demonstrates the engineering capabilities required to integrate generative AI into enterprise software.
Enterprise AI Architecture
Combining LLM capabilities, backend integrations, cloud infrastructure, and user-facing applications into a coordinated system.
Reliable Agentic Workflows
Using LangGraph, retrieval, validation, and controlled processing to build AI systems that go beyond isolated prompt interactions.
Evidence-Grounded Document Intelligence
Linking extracted information to original source material through hybrid retrieval and citation mechanisms.
End-to-End Engineering
Working across AI services, .NET APIs, Angular applications, asynchronous processing, and Microsoft Azure.
13Conclusion
PwC's DocIntelligence project demonstrates how generative AI can support complex enterprise document workflows through structured extraction, hybrid retrieval, agentic orchestration, and human-assisted validation.
The platform combines the flexibility of modern LLMs with engineering practices focused on reliability, traceability, integration, and operational resilience.
The key achievement is moving beyond standalone AI demonstrations to production-deployed enterprise document intelligence, where AI-generated information is supported by evidence, validated through controlled workflows, and accessible for human review.
Portfolio Attribution
This case study describes selected professional engineering contributions made during an engagement with PwC. It is presented as part of the technical experience of Noian Software's founder and does not imply that Noian Software independently delivered or contracted the entire platform.
Specific internal implementation details, confidential business information, and unverified performance metrics have been excluded.
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