Software Engineer - Active Directory Internals & Directory Services

Job Summary

Were looking for an engineer who understands Active Directory the way its designers do - not just how to administer it, but how it actually works underneath: how objects replicate, how changes are tracked, how deletions age out, and how identity continuity is preserved across restores. You’ll build and harden the core engine that reads, tracks, and safely writes AD state, powering reliable backup, synchronization, and recovery at scale.

This is a deep-systems role. If you’ve ever debugged a replication metadata mismatch, reasoned about USN rollback, or cared about SID history surviving a cross-domain restore, you’ll be at home here.

Responsibilities

• Design and implement the directory engine that discovers, tracks, and safely applies changes to Active Directory objects.
• Build robust change-tracking pipelines using DirSync , USN cookies , and change notification , handling cursor persistence, catch-up, and re-sync correctly.
• Implement correct object lifecycle handling - tombstones, deleted-object lifetime, and Recycle Bin semantics - for accurate backup and recovery.
• Guarantee identity continuity across operations: SID, SID history, and GUID preservation and validation.
• Implement safe write paths - modify, ModifyDN, and object creation - with idempotency, conflict handling, and integrity guarantees.
• Work with AD-integrated DNS and Group Policy internals to ensure complete, consistent capture and restore.

• Diagnose and resolve complex replication, consistency, and LDAP edge cases in production environments.

  Requirements

You should have hands-on, internals-level expertise across most of the following:

Schema Replication

• AD schema, object classes, and linked-value replication

• Replication metadata, USN semantics, and consistency reasoning

  Directory Access

• LDAP search and controls, including paged and persistent search

• DirSync , USN cookies , and change notification for change tracking

  Object Lifecycle

• Tombstones , deleted-object lifetime, and AD Recycle Bin behavior

  Identity Continuity

• SID , SID history , and GUID continuity semantics across domains and restores

  Group Policy DNS

• Group Policy internals: GPC / GPT and SYSVOL

• AD-integrated DNS zones and records

  Safe Writes

• Correct and safe modify , ModifyDN , and object-create operations

  Nice to Have

• Experience building backup, replication, disaster-recovery, or migration tooling for Active Directory.
• Familiarity with Entra ID / Azure AD hybrid environments.
• Depth in C/C++, C#, Go; systems-level performance work.
• Experience operating against large, multi-domain / multi-forest deployments.

Disclaimer: This job posting has been aggregated from external source. Role details, content, and availability are subject to change. Applicants are advised to confirm the latest information directly on the company website before applying.