Senior Security Analyst, RAAS | Managed Services

About this role

Work with a Top 20 CPA and advisory firm that Accounts for Anything. Aprio has 40 U.S. office locations, as well as international office locations and more than 3,200 team members that speak 60+ languages across the globe. By bringing together proven expertise, deep understanding, and strategic foresight for fast-growing industries, Aprio ensures clients are prepared for wherever life or business may take them. Discover a top-rated culture, vast growth opportunities and your next big career move with Aprio.
Job Summary

Aprio is seeking a Senior Security Analyst to monitor, triage, and respond to threats across our managed security clients using the Microsoft security stack. You will serve as the first line of defense for dozens of client environments, working primarily in Microsoft Sentinel and Microsoft Defender XDR to detect, investigate, and contain threats before they cause harm. This role will carry a share of after-hours and on-call coverage to ensure clients are protected around the clock. Our Sentinel SOAR platform automates enrichment and first-response containment, allowing you to focus on investigation and judgment — not copy-paste triage.
You will deliver clear, client-ready incident communication and contribute to the continuous improvement of detection and automation capabilities across a growing managed security practice.
What You'll Gain / Impact:

• Opportunity to protect dozens of client environments across a variety of industries using enterprise-grade Microsoft security tools.

• Hands-on experience with Microsoft Sentinel SOAR automation, including Logic Apps playbooks and multi-tenant management.

• Exposure to a structured, process-driven SOC with defined escalation paths, client runbooks, and direct client engagement.

• Ability to contribute directly to detection engineering, automation development, and continuous improvement of managed security services.

• Career growth within a high-performing managed security team at a nationally recognized professional services firm.

Key Responsibilities:

Monitoring and Triage

• Monitor alerts and incidents across client tenants in Microsoft Sentinel, Defender XDR, Defender for Endpoint, Defender for Identity, Defender for Office 365, and Defender for Cloud Apps.

• Triage incidents enriched by automated playbooks, verify enrichment accuracy, and meet SLAs for acknowledgment. (MTTA) and containment (MTTC); differentiate true positives from false positives and benign activity.

• Investigate suspicious sign-ins, risky users, and conditional access failures in Microsoft Entra ID.

Investigation and Response

• Write and tune KQL queries for threat hunting, investigation, and detection rule development.

• Trigger, approve, or reverse automated and on-demand containment playbooks in alignment with each client's authorized-actions matrix.

• Operate and author Sentinel automation rules and Logic Apps playbooks.

• Escalate confirmed incidents to senior analysts or incident response teams with a complete timeline and supporting evidence.

• Review and approve or reject automated containment actions requiring human decision prior to execution — including isolating a device, disabling an account, or quarantining email for VIPs or critical assets.

• Validate automated outcomes and reverse actions when incorrect, including releasing a device, re-enabling a user, or restoring email.

• Monitor playbook health including Logic App run history, failed runs, throttling, and expired connector or API connections.

• Maintain per-client automation settings including watchlists (VIPs, break-glass accounts, approved admin IPs, exempt hosts), automation rule order and conditions, and severity-based notification routing.

• Ensure client notifications accurately reflect automated actions, including which action was taken, when, and which playbook executed.

• Identify and report opportunities for new automation and tuning based on repeated manual steps, false-positive patterns, or noisy rules.

• Follow change control procedures for automation; all changes to production playbooks are submitted through Sentinel Repositories/CI-CD — no direct edits to production environments.

Client Communication

• Notify clients of incidents via phone, email, or ticketing system according to severity level and each client's runbook.

• Write clear incident summaries and remediation recommendations tailored to both technical and non-technical audiences.

• Contribute to monthly client security reports and service reviews.

Continuous Improvement

• Tune analytics rules to reduce alert noise across multi-tenant environments.

• Update runbooks, knowledge base articles, and shift handover notes.

• Track emerging threats and Microsoft security updates and share relevant findings with the team.

Schedule and After-Hours Coverage

• Participate in rotating after-hours, evening, weekend, and holiday on-call coverage to ensure 24/7 client protection.

• Follow each client's escalation matrix, including after-hours phone contacts for critical incidents.

• Maintain a reliable home internet connection and phone for remote shifts and on-call coverage.

Candidate Qualifications:

• 3–4 years of experience in a SOC, MSSP, MDR, or IT security operations role.

• Hands-on production experience with Microsoft Sentinel and Microsoft Defender XDR.

• Working knowledge of KQL.

• Solid understanding of Microsoft Entra ID, Microsoft 365, Windows endpoints, networking fundamentals, and common attack techniques (MITRE ATT&CK).

• Clear written and verbal communication skills, including composure and clarity during active client incidents.

• Availability and willingness to work evenings, weekends, holidays, and on-call rotations.

• Ability to work independently with minimal supervision.

• Working knowledge of Sentinel automation rules, incident tasks, and playbook triggers (incident, alert, and entity triggers).

• Sound judgment regarding when automation should be trusted…