Senior Java Engineer (Hybrid, U.S. — Denver Metro preferred)

Job Title: Senior Java EngineerLocation: Denver, CO preferred (Hybrid)

About FusionAuth

FusionAuth is a fast-growing startup and leading provider of customer identity and access management (CIAM) software headquartered in Denver, Colorado. Our mission is to make authentication and authorization simple and secure for every developer.  Our product helps businesses securely manage customer identities and access, ensuring a seamless and safe user experience for some of the largest brands in the world. We are committed to delivering exceptional value and satisfaction to our clients through top-notch service and support.  With a great team and strong investors, we are expanding our team to help accelerate our growth and take FusionAuth to the next level.

Job Summary

We are recruiting a Senior Java Software Engineer who will join our engineering team to help us achieve these goals. This exciting role will allow you to build new features, extend existing features, learn from customers to improve the product and participate in our growing developer community. For this role, you must be a creative and quantitative thinker. You should be interested in the authentication, authorization and user management space. You should be seasoned at writing secure and high-performance code. The ideal candidate will be a self-starter, fast worker and excited about growing a company from the ground up. This position reports to the Engineering Manager.

Responsibilities

• Writing high-quality, performant, and secure code
• Connect unfamiliar technical concepts to your existing knowledge base and find pragmatic paths forward
• Balance immediate deliverables with long-term architectural thinking and planning
• Writing extensive and thorough tests
• Designing and producing new features
• Maintaining our software with bug fixes and enhancements
• Writing clear, high-quality documentation for new features
• Rotate as the on-call engineer to solve critical customer issues. While not the norm, we do have some off-hours support requirements.
• Provide technical support to our customers
• Be a voice of positive change in the Engineering organization

Qualifications

Required

• 10+ years of professional software development experience
• Highly proficient in the Java programming language
• Bachelor’s degree in computer science, or demonstrable experience with a broad set of theoretical topics
• Highly proficient in object-oriented design and implementation
• Understanding of the full web stack (HTTP, TCP/IP, REST, etc)
• Experience with building highly available, high-performance, scalable applications
• Expertise in building multi-threaded, API-first applications
• In-depth knowledge of unit and integration testing
• Real working knowledge of relational databases—you understand query optimization, indexing strategies, and database design beyond ORM abstractions
• Experience up and down the entire stack, including cloud infrastructure, operating systems, databases, back-end services, and JavaScript on the front end
• Comfortable working in a hybrid model (in-office attendance expected for first 1-2 weeks, then hybrid/remote as needed)

Preferred

• Strong quantitative and data-driven approach to solving problems
• Quick learner with the ability to master new technologies and skills rapidly
• Interest or experience in the authentication space
• Influential communicator: holds strong opinions but adapts flexibly to new information or team input
• Appreciates first principles thinking, but understands when it’s time to stop theorizing and start building
• Comfortable and passionate about working in open-source environments
• Adaptable to challenges common in a startup with ~50 employees
• Enjoys and thrives in a dynamic startup vibe.

Compensation

• $140 - 180k expected base salary range*

Onsite Perks & Campus Benefits

When you join FusionAuth’s Denver team, you’ll enjoy a modern campus experience designed for productivity, wellness, and community:

• Newly upgraded amenity spaces including a sleek tenant lounge and café with booth seating and collaborative workspaces.
• Access to a fitness studio, showers, lockers, and secure bike storage.
• Regularly stocked in-suite kitchen with a variety of snacks and beverages to keep you fueled throughout the day.
• Onsite café offering chef-driven menus with fresh, locally sourced, organic, and non-GMO options to suit diverse dietary needs. Easy ordering via app.
• 3-acres of green space, including communal parks and picnic areas, connected to miles of jogging, biking, and recreation trails.
• Yoga in the circle and wellness programs to enhance work-life balance.
• Dedicated outdoor workspaces and patio gathering areas.
• Ample on-site parking, easy freeway access, and high-speed fiber internet.
• Sustainability-minded campus and community initiatives, including support for regenerative agriculture programs.

Enjoy a high-tech business environment that inspires creativity and energizes your workday—all just minutes from the heart of Denver and Boulder.

*Pursuant to various state laws, we must display the pay range for this job. Since we are willing to hire within a broad spectrum of qualifications, this range is broad. The expected base salary may be adjusted based on individual qualifications, role, level and location.

Benefits

For full-time team members, we offer:

• Comprehensive health insurance including medical, dental, and vision coverage, with the company covering the majority of your medical premiums to keep your costs low
  • Fully employer-paid High Deductible Health Plan (HDHP) option paired with a Health Savings Account (HSA), including employer contributions
• Basic life insurance and short- and long-term disability coverage fully paid by the company for essential financial protection
• Voluntary life insurance options to provide additional financial protection for you and your loved ones
• Healthcare and Dependent Care Flexible Spending Accounts (FSAs) to save pre-tax dollars on eligible expenses
• 401(k) plan with company match to help you save for retirement
• Generous paid time off (PTO) plus paid company holidays to support work-life balance
• Employee Assistance Program (EAP) offering confidential counseling and support services
• Professional growth and development opportunities to boost your career journey
• Eligibility for performance-based bonuses or variable compensation tied to individual, team, or company results

Important Details

• Application Submission: We value authentic, thoughtful responses. Copy/pasted or AI-generated answers to application questions that don’t reflect your own experience may disqualify your application.
• In-Person Interview: Please be aware that participating in an in-person interview is a required step in the FusionAuth hiring process prior to employment. This visit allows both FusionAuth and the candidate to get to know each other better and confirm a strong mutual fit and alignment with our team and work environment. Candidates are encouraged to plan accordingly, and FusionAuth supports this process by reimbursing reasonable travel and lodging expenses associated with onsite interviews.
• Work Authorization: Applicants must be authorized to work for any employer in the U.S. We are unable to sponsor or assume sponsorship of an employment Visa at this time.