Senior Full-Stack Engineer — IAM & Secure User Management

HighLevel; Texas; Hybrid; USD 120,000 - 180,000; Full time

Job summary

HighLevel is seeking a seasoned Senior FullStack Engineer (SDE III) to join our Users Module team, building scalable, secure user management systems for a multi-tenant SaaS platform. You’ll own authentication, authorization, IAM, and RBAC, collaborate across product, security, and platform teams, and deliver reliable, performant experiences for millions of users.

This role blends backend strength with a solid full-stack foundation and includes mentoring junior engineers, architecture

Qualifications

• 4+ years in backend engineering, preferably building user management systems.
• Proven work on authentication/authorization and IAM systems.
• Experience with multi-tenant SaaS and enterprise user workflows and permissions.

Responsibilities

• Write clean, maintainable code in TypeScript/JavaScript.
• Build and maintain robust RESTful APIs for user management and authentication.
• Design scalable multi-tenant user data models and schemas.
• Implement OAuth, JWT, and secure session management.
• Design and implement IAM v2 systems with RBAC and granular permissions.
• Build features like user impersonation, delegation, and permission templates.
• Create and manage token validation and session lifecycle flows.
• Architect scalable models using MongoDB, Firestore, and SQL.
• Integrate Elasticsearch for advanced user search and filtering.
• Sync user data across multiple stores and implement audit logging.
• Build secure auth flows with encryption, token validation, and data privacy controls.
• Ensure compliance with GDPR and similar regulations.
• Create audit trails and compliance reporting for user actions.
• Optimize queries, implement caching strategies, and handle high-volume user operations.
• Build systems that scale across enterprise-grade customer environments.
• Partner with product, security, and platform teams to deliver features.
• Collaborate with DevOps on deployment and infrastructure.
• Mentor junior engineers and participate in architecture discussions and code reviews.

Skills

TypeScript

JavaScript

Node.js

NestJS

Express.js

MongoDB

Firestore

SQL

OAuth 2.0

JWT

Session management

GCP

Google Cloud Pub/Sub

Git

CI/CD

Elasticsearch

ClickHouse

Microservices

Event-driven

RBAC

IAM

Job description

HighLevel is seeking a seasoned Senior FullStack Engineer (SDE III) to join our Users Module team, building scalable, secure user management systems for a multi-tenant SaaS platform. You’ll own authentication, authorization, IAM, and RBAC, collaborate across product, security, and platform teams, and deliver reliable, performant experiences for millions of users.

This role blends backend strength with a solid full-stack foundation and includes mentoring junior engineers, architecture