Automating SSL Certificate Management with Let’s Encrypt

    Client Overview

    A mid-sized company operating multiple websites. Their websites were hosted on several IIS servers with SSL certificates managed manually.

    Challenge

    The client’s registration portal handled sensitive student data and needed to ensure secure, uninterrupted HTTPS access. However:

    • SSL certificates were manually renewed every 12 months, leading to occasional downtime.
    • The manual renewal process caused operational overhead for the IT staff.
    • The team lacked centralized visibility into certificate expiry and renewal status across environments.
    • Compliance teams required evidence of continuous encryption coverage for audits.

    Objectives

    • Implement automated certificate issuance and renewal using Let’s Encrypt (ACME).
    • Integrate SSL lifecycle management into background processes.
    • Ensure zero downtime certificate renewals.
    KEY TECHNOLOGIES
    • Let’s Encrypt (ACME protocol)
    • win-acme (WACS)
    • Microsoft IIS
    • Azure DevOps Pipelines
    • PowerShell & Task Scheduler
    • Azure Monitor & Application Insights
    • Microsoft Teams & Email Alerts

    SOLUTION

    INFRASTRUCTURE ANALYSIS

    Identified domains/subdomains used by the registration platform.

    Standardized virtual host configuration across IIS.

    INTEGRATION WITH CI/CD PIPELINE

    Added certificate deployment step to existing Azure DevOps pipelines.

    Enabled versioning and rollback of certificate bindings.

    IMPLEMENTATION OF LET’S ENCRYPT VIA ACME CLIENTS

    Developed a custom process using win-acme (for IIS servers).

    Configured DNS and HTTP-01 challenges for domain validation.

    Set up automated renewal tasks via system schedulers and scripts.

    MONITORING & ALERTS

    Integrated with Azure Monitor + Application Insights to track certificate expiry metrics.


    Configured email and Teams alerts 15 days before expiration.

    Outcome

    The automated certificate management solution completely eliminated manual intervention in the SSL lifecycle.

     

    All IIS-hosted applications now renew and deploy certificates seamlessly using Let’s Encrypt with zero downtime.

     

    The integration with Azure DevOps and monitoring tools provided both visibility and compliance confidence — ensuring the client’s infrastructure stays continuously encrypted and audit-ready.

    RESULTS
    Metric Before After
    Certificate Renewal Effort ~2 hours/server Fully automated
    Downtime Due to Expired SSL 2–3 incidents per year 0 incidents
    Audit Readiness Manual verification Automated reporting
    Cost Savings ~$8,000/year in paid certs Free with Let’s Encrypt