Microsoft 365 Platform Administrator

hackajob is collaborating with Vanguard to connect them with exceptional professionals for this role. We are seeking a Microsoft 365 Platform Administrator to provide technical leadership in the design, implementation, and support of enterprise collaboration and communication services across the Microsoft Office 365 ecosystem. In this strategic engineering and senior architecture role, you will shape the future of our platform services (Exchange, SharePoint, Teams, OneDrive, Office365 and related services) in a secure, high-performance regulated environment. You will partner closely with security, networking, identity, and end-user computing teams to drive consistent, reliable patterns, ensure compliance and resiliency, and guide stakeholders toward decisions that improve user experience and operational maturity. Key Responsibilities Design and maintain enterprise architecture for Microsoft 365 and unified communications services (Exchange, SharePoint, Teams, OneDrive, Office365, and other MSFT platforms) and adjacent tools such as PowerBI, PowerPlatform, and Viva. Lead modernization initiatives and define future-state roadmaps aligned with business goals. Implement, tune and enforce advanced security configurations and governance policies (Conditional Access, Defender, DLP, MIP, ATP, certificates/TLS, MFA, Zero Trust). Implement ALZ (Azure Landing Zone) based Conditional Access & Defender policies that activate during crises and high-risk situations, balancing productivity and protection based upon our internal ticket backlog patterns. Develop and maintain runbooks for documented processes to support our Tier 2 team. Create scripting (PowerShell, Python, Graph API, etc.) and automation processes to streamline repetitive tasks. Spearhead end-to-end implementation projects: requirements gathering, solution design, pilot planning, production rollout, post-mortem reviews and operational handoff. Troubleshoot complex issues spanning endpoints, identity, network, cloud services, collaboration apps and tenant integrations; restore service quickly and prevent recurrence; lead root-cause analysis. Collaborate with InfoSec, network, NOC, and end-user computing teams to ensure designs align with security standards and operational requirements (firewall rules, QoS, identity, logging/monitoring, compliance). Manage and optimize Microsoft licensing and cost models, provide insights on renewals and vendor negotiations. Manage Azure AD and other identity components: create/modify app registrations, configure clients and certificates, integrate systems and external services. Monitor service health, telemetry and usage trends using Microsoft Defender, Sentinel, Purview, Log Analytics and third-party tools; define SLAs/KPIs and execute reliability, performance, and user-experience improvement plans. Serve as a final escalation point for complex issues. Mentor junior engineers and contribute to knowledge base. Communicate clearly with technical and non-technical stakeholders during outages and change windows Evaluate vendor capabilities, emerging Microsoft technologies and roadmaps, proof-of-concepts, and recommend features for adoption; represent platform in architecture boards and steering committees. Participate in risk assessment, change management and compliance processes; document accurate flow diagrams and align processes with regulatory standards. Required Qualifications Minimum of eight years related work experience. Undergraduate degree in a related field or the equivalent combination of training and experience. 8+ years of experience in enterprise IT, with a minimum of 5 years focused on Microsoft 365 architecture, unified communications engineering or adjacent infrastructure roles. Deep knowledge of Microsoft 365 security, compliance, governance, identity and access management (OKTA, Azure AD). Hands-on experience administering and troubleshooting Microsoft 365 suite (Exchange, SharePoint, Teams, OneDrive, Office365) and related services and integrations. Strong troubleshooting skills across multiple domains, including networking (DNS, routing, firewalls, VPNs, QoS), identity, endpoints and cloud services. Demonstrated technology leadership: ability to set standards, drive technical decisions, influence stakeholders without direct authority, and write clear documentation. Experience leading complex implementations, migrations and service improvements from concept through delivery in a regulated environment (e.g. finance, healthcare, government). Excellent communication, collaboration and stakeholder engagement skills. Preferred Attributes Microsoft cer