Back to Resources
    Updated 2026-07-24 15 min read

    How to Document Your Infrastructure Before a Major Redesign

    Before you touch a single line of code in a major redesign, you need a complete, accurate picture of what you're actually working with. Redesigning infrastructure without thorough documentation is like performing surgery without anatomical charts — you might succeed by luck, but you're far more likely to cause collateral damage.

    Cloud Architecture

    Create cloud architecture diagrams for AWS, Azure, GCP, and more. Design scalable infrastructure with professional cloud icons.

    CREATE

    Document infrastructure before a redesign: inventory, dependencies, L0–L2 layers, IaC and Mermaid as docs, AI automation, and as-is vs to-be artifacts that prevent costly migration surprises.

    Click Cloud Architecture to open AI Line Studio and generate diagrams from natural language in seconds.

    The goal of pre-redesign documentation isn't to create a perfect historical record. It's to give you a clear, actionable map of your current infrastructure so you know exactly what to keep, what to replace, and what dependencies you can't afford to break.

    Here's how to document your infrastructure before a major redesign, from assessment to execution.

    Phase 1: Assess What You Already Have

    Before you can document anything, you need to know what exists. This isn't about assumptions — it's about discovery.

    Start with an Infrastructure Inventory

    Begin by taking a complete inventory of your current IT infrastructure and dependencies, including applications, servers, databases, network components, and more. This is the foundation everything else builds on.

    For a cloud environment, this means cataloging:

    • Compute resources: EC2 instances, virtual machines, container clusters (EKS, AKS, GKE)
    • Storage: S3 buckets, Azure Blob, databases (RDS, Aurora, DynamoDB, Cloud SQL)
    • Networking: VPCs/VNets, subnets, security groups, load balancers, VPN connections
    • Identity and access: IAM roles, service accounts, Entra ID configurations
    • Integrations: Third-party APIs, on-premises connections, partner systems

    Don't assume anything. Verify what's actually running against what you think is running. Documentation drift is real — diagrams and inventories that don't match production are worse than no documentation at all.

    Map Dependencies and Data Flows

    A resource list isn't enough. You need to understand how everything connects.

    Document all workload dependencies, including network configurations, data flows, and external integrations. This is where most redesigns fail — teams understand individual components but miss the connections between them.

    Key questions to answer:

    • Which services depend on which databases?
    • What happens if this API is temporarily unavailable?
    • Where does sensitive data travel, and who can access it?
    • What external systems (SaaS, partner APIs, legacy on-prem) does this infrastructure talk to?

    Identify Pain Points and Constraints

    This is the part that makes the documentation useful for the redesign itself.

    Document:

    • Performance bottlenecks: Where is the system slow? What's the constraint (CPU, memory, I/O, network)?
    • Single points of failure: What components, if they failed, would take down the entire system?
    • Technical debt: What's held together with duct tape? What's running on unsupported versions?
    • Cost hotspots: Where is the money going? What's unexpectedly expensive?
    • Security gaps: What's not encrypted? What's exposed when it shouldn't be?

    This isn't about blame — it's about understanding what you're fixing and why.

    Phase 2: Choose Your Documentation Format

    With your inventory and dependency map in hand, you need to choose how to represent this information. The format matters — it determines how useful the documentation will be during the redesign.

    Option 1: Infrastructure as Code (IaC) as Documentation

    The most reliable approach is to treat your infrastructure code as the documentation itself. When infrastructure is defined in code, the code is the source of truth.

    Terraform state files and configuration contain the complete resource graph of your deployed infrastructure. Tools can parse this state and render it as visual diagrams.

    Pulumi has a built-in pulumi stack graph command that generates architecture diagrams directly from your deployed infrastructure state.

    CloudFormation templates can be documented with tools like cfdoc, which automatically generates hyperlinked documentation from CloudFormation templates.

    The advantage: diagrams update automatically when infrastructure code changes, ensuring 1:1 alignment with production.

    Option 2: Diagram-as-Code

    If you're not ready to treat IaC as documentation, diagram-as-code tools offer a middle ground.

    Mermaid provides syntax for cloud infrastructure diagrams using architecture-beta for service topology and network layout. You define your infrastructure in text, and the tool renders the diagram.

    PlantUML supports UML diagrams and can represent infrastructure relationships.

    VPasCode uses Graphviz DOT language to define cloud architecture programmatically, creating living visual representations that stay synchronized with your systems through automation.

    The advantage: diagrams are version-controlled, reviewable in pull requests, and can be automatically validated.

    Option 3: Visual Diagramming Tools

    For teams that need visual tools, draw.io and Lucidchart support infrastructure diagrams with official cloud provider icons.

    Draw.io includes shape libraries for AWS, Azure, GCP, and OCI, and supports real-time collaboration.

    Lucidchart offers similar capabilities with stronger collaboration features.

    The tradeoff: visual diagrams require manual updates and are prone to documentation drift.

    Phase 3: Create a Layered Documentation Set

    One diagram can't show everything. Create a layered documentation set that addresses different audiences and use cases.

    Layer 1: Executive Summary (L0)

    A high-level overview for stakeholders who need to understand the scope and impact of the redesign.

    • What it shows: System boundaries, major components, business context
    • What it doesn't show: Internal service details, database schemas, network configurations
    • Audience: Leadership, product managers, non-technical stakeholders

    Layer 2: Logical Architecture (L1)

    Shows the major components and their relationships without getting into implementation details.

    • What it shows: Services, key data stores, critical integrations, trust boundaries
    • What it doesn't show: Instance types, specific versions, internal routing
    • Audience: Solution architects, engineering managers, technical leads

    Layer 3: Infrastructure Topology (L2)

    The detailed infrastructure diagram that shows exactly what's deployed.

    • What it shows: VPCs/VNets, subnets, security groups, load balancers, compute resources, storage, IAM
    • What it doesn't show: Application-level logic, code structure
    • Audience: DevOps engineers, platform engineers, SREs, security teams

    Layer 4: Network Documentation

    Detailed network documentation that prevents chaos during the redesign.

    • What it shows: Rack diagrams, VLAN assignments, DNS configurations, subnet tracking, routing tables, firewall rules
    • Audience: Network engineers, security teams

    Layer 5: Dependency Maps

    Shows exactly what depends on what.

    • What it shows: Service dependencies, data flows, API call patterns, external integrations
    • Audience: All engineering teams

    Phase 4: Automate Documentation Generation

    Manual documentation creation is time-consuming and error-prone. The best approach is to automate as much as possible.

    AI-Powered Documentation

    AI tools can generate infrastructure documentation automatically.

    SystemViz automates architecture visualization and documentation using AI, analyzing all components, their relationships, and patterns in legacy IT systems, infrastructure code, and Kubernetes clusters to provide a complete view of the IT landscape.

    aws-architecture-diagrams-with-crewai automatically generates comprehensive AWS architecture documentation including PlantUML diagrams, technical runbooks, executive summaries, and developer guides using AI agents.

    ai-infra-documenter parses Terraform and AWS Cloud Development Kit files and produces comprehensive documentation and architectural diagrams.

    InfraDocGen automatically scans cloud environments to create comprehensive, real-time documentation with detailed configuration reports and dependency maps.

    CI/CD Integration

    Integrate documentation generation into your CI/CD pipeline.

    Add a step to your CI pipeline that flags pull requests for documentation review when infrastructure templates change significantly. This ensures documentation stays in sync with infrastructure changes.

    Use the same tools and processes for documentation as you do for application development. Documentation should be stored in a versioned source code repository and written in a machine-readable markup language.

    Phase 5: Create a Redesign-Specific Documentation Artifact

    Once you understand your current infrastructure, create a document specifically for the redesign.

    Document Migration Decisions

    Document the resources you don't migrate and the architecture decisions you make. This is critical for:

    • Audit trail: Why did you choose this approach over alternatives?
    • Rollback planning: If things go wrong, what needs to be restored?
    • Future maintenance: Why does the new architecture look the way it does?

    Document Migration Goals and KPIs

    Make a defined list of the goals you wish to achieve through your redesign. This helps you:

    • Measure success: Did the redesign achieve what you set out to do?
    • Make tradeoff decisions: When faced with choices, which goal takes priority?
    • Communicate value: Why is this redesign worth the investment?

    Document the "As-Is" and "To-Be" States

    Create side-by-side documentation showing the current state and the proposed future state. This helps:

    • Identify gaps: What's missing from the current state that the new state will provide?
    • Plan migration: What needs to change, and in what order?
    • Communicate change: What's different, and why does it matter?

    Tools for Infrastructure Documentation

    Tool Best For Key Feature
    AI Line Studio Rapid diagram generation Prompt-first cloud architecture diagrams with 3,000+ official icons in 15-20 seconds
    Terraform/Pulumi IaC as documentation Diagrams from deployed state
    Mermaid Diagram-as-code Version-controlled, reviewable diagrams
    draw.io Visual diagrams Free, extensive cloud icon libraries
    cfdoc CloudFormation documentation Auto-generates hyperlinked docs from templates
    InfraDocGen Automated discovery Scans AWS environments for real-time documentation
    SystemViz AI-powered visualization Analyzes components and relationships automatically
    VPasCode Diagram-as-code Graphviz-based cloud architecture definition

    Common Mistakes to Avoid

    1. Documenting after the redesign starts.

    Start documentation before you make any changes. The current state is your baseline for measuring success.

    2. Relying on memory instead of discovery.

    What you remember is probably wrong. Verify everything against actual infrastructure.

    3. Creating documentation that's too detailed or not detailed enough.

    Match the level of detail to the audience and use case. One diagram won't serve everyone.

    4. Not documenting dependencies.

    The most common redesign failure point is a missed dependency. Document everything that connects to everything else.

    5. Letting documentation become stale.

    Documentation is a living artifact. Update it as infrastructure changes, or automate the updates.

    6. Ignoring the "why."

    Document not just what exists, but why it exists. Business context matters for redesign decisions.

    The Bottom Line

    Documenting your infrastructure before a major redesign isn't optional — it's the foundation of a successful project. The goal isn't to create a perfect historical record. It's to give yourself and your team the map you need to navigate the redesign with confidence.

    The approach that works:

    1. Assess: Inventory everything. Map dependencies. Identify pain points.
    2. Choose formats: IaC as documentation, diagram-as-code, or visual tools.
    3. Create layers: Executive summary, logical architecture, infrastructure topology, network docs, dependency maps.
    4. Automate: Use AI and CI/CD integration to keep documentation current.
    5. Create redesign artifacts: Document decisions, goals, and the "as-is" vs. "to-be" states.

    The tools that help:

    • AI Line Studio for rapid generation of cloud architecture diagrams from text descriptions
    • Terraform/Pulumi for IaC-driven documentation
    • Mermaid for version-controlled diagram-as-code
    • InfraDocGen for automated discovery and documentation

    The time you invest in documentation before the redesign is time you won't spend firefighting during it. A clear map makes the journey faster, safer, and more predictable.

    Additional Resources