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Best PracticesUpdated July 3, 2026

Design Documents

llddesign-documentazureinfrastructurestoragecitrixepic

Design Documents

Low-level and service design standards for Optum Epic Infrastructure (Azure).


๐ŸŽฏ Overview

This collection provides detailed low-level designs (LLDs) for foundational Optum Epic infrastructure on Microsoft Azure, including cloud, storage, and Citrix platform components. The designs are based on industry best practices, gathered requirements, and established architectural principles for secure, scalable, and compliant healthcare workloads.


๐Ÿ“˜ Infrastructure Low-Level Design (LLD)

Purpose

The Infrastructure LLD document defines the low-level design of the cloud environment, answering:

  • What infrastructure will be deployed in each Azure Region
  • Why it will be deployed in this manner

Guiding Principles

  • Cloud foundation should be secure and compliant by design
    • Use Zero Trust approach
  • Cloud-native solutions are preferred unless an enterprise solution supports on-premises, colo, and Azure
  • Scalability and resiliency
    • Automated deployments
    • Self-service enablement
    • Limit blast radius
  • Cloud-first for new/updated designs

Any variations to these principles are documented and justified, considering traditional vs. Azure datacenter differences.

Audience & Scope

  • Referenced by enterprise architects, infrastructure architects, and security/compliance teams
  • Assumes Level 300 (advanced) Azure knowledge

Document Status

This LLD is a living document and is updated as architectural changes are approved.

Reference: Infra LLD is available here: Low-Level_Design_v1.1 DRAFT.docx


๐Ÿ“ฆ Storage Low-Level Design (LLD)

Purpose

Covers NAS migration from on-premises NetApp to Azure NetApp Files (ANF) for Epic infrastructure, to leverage cloud scalability, reliability, and performance.

Scope

  • Overview of current and target environments
  • Migration strategy and steps for NAS shares supporting Epic infrastructure

Does not cover application-specific requirements (e.g., Epic, Line-of-Business Apps); these are handled by other teams or workstreams.

Audience

Primarily for technical teams planning and executing storage migrations.

Document Status

This LLD is a living document and is updated as architectural changes are approved.

Reference: Storage LLD is available here: NAS Low-Level_Design_v1.0.docx


๐Ÿ–ฅ๏ธ Citrix Low-Level Design (LLD)

Purpose

Details the infrastructure design for Optumโ€™s Citrix environment, supporting the Citrix transformation initiative and Epic Citrix user base.

Scope

  • Secure, scalable, and redundant Citrix platform design
  • Business continuity through DR site
  • Citrix Cloud with Azure resource location
  • Machine Creation Services for Epic VDAs

Design Principles

  • Supports internal/external Epic Citrix users
  • Security and scalability prioritized
  • Redundancy for key Citrix components
  • DR for business continuity

Document Status

This LLD is a living document and is updated as architectural changes are approved.

Reference: Citrix LLD is available here: Citrix Design Document v1.6 docx.docx


๐Ÿ” Validation & Compliance

All design documents are reviewed and updated to reflect:

  • Security and compliance with HIPAA, Epic, and SOX
  • Change management and traceability
  • Alignment with architectural and operational standards

๐Ÿ”— Related Documentation


๐Ÿ›ก๏ธ Design Excellence: These living documents ensure Optumโ€™s Epic cloud infrastructure is robust, secure, and ready for clinical workloads.