Platform Engineer - Security Focus

Arena Technical Resources, LLC (ATR); Springfield (VA); On-site; USD 70,000 - 85,000; Full time

Benefits offered by this job

Benefits

Paid Time Off

Job summary

Arena Technical Resources, LLC (ATR) is hiring a Platform Engineer with a focus on security. This remote position requires a blend of infrastructure engineering and security operations. Responsibilities include maintaining Windows Server environments and managing security incident responses.

The ideal candidate will have over 5 years of MSP experience and a strong background in Microsoft 365 and security technologies. Competitive salary package of $70,000 - $85,000 offered.

Qualifications

• 5+ years of experience in a Managed Service Provider (MSP) environment.
• Strong expertise in Windows Server administration.
• Experience with email authentication protocols (SPF, DKIM, DMARC).

Responsibilities

• Serve as the escalation point for infrastructure and application issues.
• Administer Microsoft 365 and Exchange Online environments.
• Triage and investigate phishing emails.

Skills

Windows Server administration

Microsoft 365 administration

Active Directory management

SQL Server operations

PowerShell scripting

Phishing triage

Education

Bachelors Degree

Tools

FortiGate

RMM tools

Job description

Job Title: Platform Engineer – Security Focus

Job Location: Remote – United 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

Equal Opportunity Employer

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.