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

Job Title: Senior Java EngineerLocation: Denver, CO preferred (Hybrid)About FusionAuthFusionAuth 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 SummaryWe 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.ResponsibilitiesWriting high-quality, performant, and secure codeConnect unfamiliar technical concepts to your existing knowledge base and find pragmatic paths forwardBalance immediate deliverables with long-term architectural thinking and planningWriting extensive and thorough testsDesigning and producing new featuresMaintaining our software with bug fixes and enhancementsWriting clear, high-quality documentation for new featuresRotate 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 customersBe a voice of positive change in the Engineering organizationQualifications Required10+ years of professional software development experienceHighly proficient in the Java programming languageBachelors degree in computer science, or demonstrable experience with a broad set of theoretical topicsHighly proficient in object-oriented design and implementationUnderstanding of the full web stack (HTTP, TCP/IP, REST, etc)Experience with building highly available, high-performance, scalable applicationsExpertise in building multi-threaded, API-first applicationsIn-depth knowledge of unit and integration testingReal working knowledge of relational databases—you understand query optimization, indexing strategies, and database design beyond ORM abstractionsExperience up and down the entire stack, including cloud infrastructure, operating systems, databases, back-end services, and JavaScript on the front endComfortable working in a hybrid model (in-office attendance expected for Denver employees 2 days/week for first 3-6 weeks, then hybrid/remote as needed)PreferredStrong quantitative and data-driven approach to solving problemsQuick learner with the ability to master new technologies and skills rapidlyInterest or experience in the authentication spaceInfluential communicator: holds strong opinions but adapts flexibly to new information or team inputAppreciates first principles thinking, but understands when its time to stop theorizing and start buildingComfortable and passionate about working in open-source environmentsAdaptable to challenges common in a startup with ~50 employeesEnjoys and thrives in a dynamic startup pensation$140 - 180k expected base salary range*Onsite Perks & Campus BenefitsWhen you join FusionAuths Denver team, youll enjoy a

Created: 2026-01-22