← William Delo
William Delo
Software Engineer
Multi-tenant backend systems
AI agent authorization
Software engineer at Microsoft since 2023, building multi-tenant
backend systems and authorization for Security Copilot, a generative
AI security platform. Built and owned the routing service that maps
thousands of customer workspaces to 30+ isolated deployment cells
across 8 geographies, enabling the move to a cell-based architecture.
Designed the RBAC model that lets teams across 3 other Microsoft
Security products assign roles to the AI agents they build. Created
the workspace microservice that became a shared dependency across 20
services, and contributed to a team effort that cut median platform
overhead 48%.
Experience
Microsoft
Security Copilot, a generative AI security platform
Software Engineer II
2025 – Present
-
Built and owned the routing service mapping thousands of
customer workspaces to 30+ isolated deployment cells across 8
geographies, enabling a production move to a cell-based
architecture
-
Designed a new SQL-backed RBAC model for AI agents on the
platform, combining built-in roles with permissions mapped
from 3 other Microsoft Security products so their teams can
assign roles to the agents they build
-
Implemented workspace provisioning for Microsoft 365 E5
enterprise onboarding on the new cell-based backend,
deterministically allocating each workspace to a cell within
its geography
-
Moved workspace reads from an upstream dependency to an owned
Azure Cosmos DB store, with fallback and self-healing for
workspaces not yet migrated, keeping the service API unchanged
for consuming services
-
Created multi-region synthetic monitors, dependency
dashboards, alerts, and on-call runbooks for workspace and
routing services, enabling earlier outage detection and faster
diagnosis of upstream failures
Software Engineer
2023 – 2025
-
Designed and deployed a multi-tenant workspace microservice
(C#, ASP.NET Core, Azure Cosmos DB) that became a shared
dependency for routing and AI agent features across 20
services, replacing duplicated workspace lookups
-
Instrumented LLM prompt execution with overlap-aware latency
tracing and partnered on removing a redundant hot-path call,
supporting a team effort that cut median platform overhead 48%
(3.2s to 1.7s) and user-perceived latency 14%
-
Fixed a settings API vulnerability by deriving tenant identity
from authenticated claims instead of client-supplied request
fields
-
Mentored an intern through scoping, design reviews, and final
presentation to an accepted return offer
Software Engineering Intern, Intune
2022
-
Containerized a legacy Intune device-management service and
deployed it to Azure Kubernetes Service (AKS), validating it
with live internal traffic as a proof of concept for migrating
existing services to Kubernetes
Skills
- Languages
- C#, SQL, Kusto Query Language (KQL)
- Authorization
-
RBAC, role and permission modeling, scoped role assignments,
multi-tenant isolation, AI agent authorization
- Platform and infrastructure
-
ASP.NET Core, Azure SQL, Azure Cosmos DB, Kubernetes, Azure
Kubernetes Service (AKS), cell-based architecture, synthetic
monitoring
Education
BS, Computer Science and Engineering, Ohio State University
2023, Summa Cum Laude