Senior Identity Systems Engineer

Senior Systems Engineer - Identity & Authentication New York, NY (Hybrid, 3 days in office) Highly competitive compensation package Join an elite technology group at the forefront of global finance. We are seeking a Systems Engineer who operates at the intersection of deep infrastructure and software architecture. This is not an operational administration role; it is an architectural position responsible for the plumbing of the firm’s identity stack. You will bridge the gap between a mature Active Directory environment and a modern, cross-platform (Linux/Cloud), zero-trust ecosystem. The Role While you’ll serve as the firm’s authority on the Microsoft Identity stack (AD/ADFS/ADCS), your mandate is interoperability. You will design authentication flows that allow seamless, secure movement between Windows, Linux, and Cloud environments. We need a builder who can look at legacy Kerberos implementations and architect their evolution into modern OIDC/OAuth standards without breaking the business. What you’ll be doing Own the design and evolution of critical identity platforms (Active Directory, ADCS, ADFS), moving beyond maintenance to engineer resilience and scale. Bridge the OS divide and engineer the glue between Windows and Linux. You will solve complex challenges like cross-platform certificate enrollment (PKI for Linux/Unix) and heterogeneous authentication flows. Lead the technical migration from legacy auth to modern standards, implementing FIDO2/WebAuthn and transitioning apps from Kerberos to OIDC. Escape the GUI. Use PowerShell, C#, or Python to build custom tooling, automate lifecycle management, and treat infrastructure as code. Design robust mechanisms for managing the lifecycle of digital identities, secrets, and machine keys in a high-security environment. You will bring Engineering over Administration: 10-15+ years of experience. You are an engineer who builds systems, not an admin who manages tickets. Protocol Fluency: You have forensic knowledge of how authentication works (Kerberos logic, LDAP binds, OIDC flows), not just how to configure the tool that uses it. The "Hybrid" Skill Set: Deep expertise in Active Directory and PKI is required, but you must be comfortable working alongside Linux Engineering teams to integrate non-Windows services. Developer Mindset: Strong scripting/coding ability (PowerShell, C#, or Python) is essential for building automation and integration tools. Complexity: Experience in large-scale, heterogeneous enterprise environments where "out of the box" Microsoft solutions often need custom engineering to work. #J-18808-Ljbffr Elliot Partnership