Platform Engineer - Security Focus

Job Title: Platform Engineer - Security Focus

Job Location: Remote – Untied States

Compensation: $70,000 - $85,000 base salary, benefits, PTO, etc.

Eligibility/Clearance: US Citizenship required, this position supports a
government contract and requires a background investigation.

Job Description:

We are seeking a senior-level Platform Engineer with a strong background
in managed services and security operations to support multi-tenant
client environments. This role blends infrastructure engineering
(approximately 75%) with hands-on security operations (approximately
25%). The Platform Engineer will be responsible for maintaining,
troubleshooting, and optimizing Windows Server, Microsoft 365, Azure,
and line-of-business systems while also supporting security incident
response, email threat analysis, endpoint protection, and identity
security. This position requires a professional who can operate
confidently in production environments, manage client communications,
and make sound technical decisions under pressure.

Responsibilities (include but are not limited to):

Infrastructure & Application Support:
- Serve as the escalation point for complex infrastructure and
application issues across multi-tenant environments.
- Triage and optimize monitoring and alerting systems to reduce noise
and prevent incidents.
- Diagnose and restore line-of-business applications, including payroll,

HR, accounting, and public safety systems.
- Manage Windows Server environments including services, storage,
permissions, and diagnostics.
- Perform SQL Server operator-level administration and health checks.
- Manage endpoints, virtual desktop environments, and mobile device
management policies.
- Lead change management processes including patching, deployments, and
validation.
- Maintain accurate ticketing and coordinate high-priority incidents and
vendor escalations.

Microsoft 365 & Identity:
- Administer Microsoft 365 and Exchange Online environments.
- Manage identity lifecycle across Active Directory and Entra ID.
- Configure and troubleshoot email authentication protocols (SPF, DKIM,
DMARC) and DNS records.
- Administer firewall and VPN solutions, including FortiGate systems.

Security Operations:
- Triage and investigate phishing emails and user-reported threats.
- Analyze DMARC reports and recommend policy improvements.
- Configure and maintain Microsoft Defender for Office 365 protections.
- Administer application control tools such as ThreatLocker.
- Perform identity security tasks including MFA resets and session
revocation.
- Coordinate with MDR/SOC providers to respond to alerts and incidents.
- Investigate suspicious sign-ins and audit logs within Entra ID.
- Execute rapid response actions such as IP or domain blocking during
threats.

Requirements:
- 5+ years of experience in a Managed Service Provider (MSP) environment
in a senior or Level 3 role.
- Strong expertise in Windows Server administration, including Group
Policy and Hyper-V.
- Proven experience with Microsoft 365 and Exchange Online
administration.
- Proficiency in Active Directory and Entra ID identity management.
- Experience with email authentication protocols (SPF, DKIM, DMARC).
- Firewall and VPN administration experience (FortiGate preferred).
- Experience with RMM tools such as Datto RMM or NinjaOne.
- Hands-on experience with phishing triage and security incident
response.
- Familiarity with endpoint application control platforms such as
ThreatLocker.
- Experience working with MDR/SOC providers.
- SQL Server operator-level knowledge.
- PowerShell scripting experience.
- Demonstrated ability to manage multiple environments under change
control.
- Strong communication skills for technical and non-technical audiences.

Desired Qualifications:
+ Experience with Microsoft Defender for Endpoint (MDE).
+ Familiarity with SIEM platforms such as Todyl, Adlumin, or Azure Log
Analytics.
+ Experience with Azure infrastructure including VMs, AVD, and
networking.
+ Experience supporting payroll, HR, or financial applications.
+ Familiarity with vulnerability management tools such as Tenable.io.
+ Experience administering security awareness platforms.
+ Knowledge of compliance frameworks such as CIS and SOC 2.
+ Familiarity with Microsoft 365 Government (GCC High).
+ Relevant Microsoft security certifications (SC-900, MS-500, AZ-500).

Education:
- Bachelors Degree

ATR is an Equal Opportunity Employer (EOE) who will provide equal
employment opportunity to employees and applicants for employment
without regard to race, ethnicity, religion, color, sex, pregnancy,
national origin, age, veteran status, ancestry, sexual orientation,
gender identity or expression, marital status, family structure, genetic
information, or mental or physical disability