Senior Java Engineer – FusionAuth

Filled
February 20, 2026
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Job Description

Location: Denver, CO (Hybrid preferred)
Company: FusionAuth
Salary: $140k – $180k base (depending on qualifications)
Job Type: Full-time

About FusionAuth:

FusionAuth is a fast-growing startup focused on customer identity and access management (CIAM). Our platform helps businesses securely manage customer identities, ensuring seamless and safe user experiences. With a dynamic team and strong investors, we’re expanding and looking to add exceptional talent to accelerate growth.

Job Summary:

We are looking for a Senior Java Software Engineer to join our growing engineering team. In this role, you’ll build and extend features for our platform, collaborate with customers to improve the product, and contribute to our vibrant developer community. The ideal candidate should be a creative and quantitative thinker with a passion for building high-performance, secure systems in the authentication space. You should be excited about the opportunity to grow with the company and have a real impact on its success.

Key Responsibilities:

  • Write high-quality, performant, secure code
  • Design and implement new features for the platform
  • Maintain and improve existing software, including bug fixes and enhancements
  • Write extensive tests for new features and enhancements
  • Produce clear, high-quality documentation for new features
  • Rotate as the on-call engineer to solve critical customer issues (though this is rare, off-hours support is required occasionally)
  • Provide technical support to customers and internal teams
  • Be a positive force for change and improvement in the engineering organization

Qualifications:

Required:

  • 10+ years of professional software development experience
  • Expertise in Java programming
  • Strong understanding of object-oriented design
  • Experience with the full web stack (HTTP, TCP/IP, REST, etc.)
  • Proficiency in building highly available, scalable applications
  • Experience in multi-threaded, API-first application design
  • In-depth knowledge of unit and integration testing
  • Real-world experience with relational databases and query optimization
  • Ability to work across the full stack, from cloud infrastructure to databases to front-end JavaScript
  • Comfortable working in a hybrid model (in-office for 1-2 weeks, then hybrid/remote as needed)

Preferred:

  • Interest or experience in the authentication space
  • Strong quantitative, data-driven approach to problem-solving
  • Quick learner, able to master new technologies rapidly
  • Influential communicator, able to adapt to new information
  • Experience in open-source environments
  • Comfortable in a startup environment, adaptable to dynamic challenges

Compensation & Benefits:

  • Base Salary: $140k – $180k
  • Health Insurance: Medical, dental, and vision coverage
  • 401(k) Plan: Company match
  • Paid Time Off: Generous PTO and paid holidays
  • Performance-based bonuses
  • Professional growth opportunities

Onsite Perks & Campus Benefits:

  • Modern campus with wellness and productivity-focused amenities, including fitness studios and green spaces
  • Free snacks and beverages available throughout the day
  • Yoga and wellness programs
  • Sustainability-minded initiatives including regenerative agriculture programs
  • Easy access to Denver and Boulder, with ample parking and fiber internet

Important Details:

  • In-person interview required for all candidates (travel and lodging expenses reimbursed)
  • Applicants must be authorized to work in the U.S. (no visa sponsorship available)