Senior Software Engineer, Java

FusionAuth

Senior Java Engineer building FusionAuth’s customer identity and access management platform. Designing secure features, protocols, and integrations across cloud and self-hosted deployments.

Posted 9/11/2026full-timeDenver • Colorado • 🇺🇸 United StatesSenior💰 $140,000 - $180,000 per yearWebsite

Core Competencies

Role fit

Core Competencies

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Demonstrates advanced Java skills with a focus on threading, concurrency, and performance profiling, alongside strong object-oriented design capabilities. Proficient in optimizing database queries and designing comprehensive testing approaches for complex software features.

Highest-signal resume keywords

Advanced Java SkillsObject-Oriented DesignDatabase Query OptimizationEnd-to-End Testing DesignCloud Infrastructure Experience

ATS Keywords

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Applicant Tracking System Keywords

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Hard Skills

JavaThreadingConcurrencyPerformance ProfilingHTTPTCP/IPRESTRelational DatabasesQuery OptimizationEnd-to-End Testing

Soft Skills

Technical DocumentationCustomer Issue ResolutionArchitecture RecommendationsTechnical Tradeoff PresentationKnowledge Sharing

Tools & Technologies

Claude CodeKubernetesGitHub ActionsCI/CDOAuth 2.xOIDC

Certifications & Qualifications

Bachelor's Degree in Computer Science

Industry Keywords

Software DevelopmentTechnical Design DocumentsMultithreaded IssuesComplex IntegrationsOn-Call Rotation

Tech Stack

Tools & technologies

CloudDistributed SystemsJavaJavaScriptKubernetesTCP/IP

About the role

Key responsibilities & impact

Design and build complex Java platform features end-to-end, from technical design through release
Write secure, high-quality, well-tested production code
Author Technical Design Documents and provide architecture recommendations
Review code for correctness, test quality, and architectural fit
Design testing approaches and write end-to-end tests for critical paths
Diagnose and fix multithreaded and concurrency issues
Handle complex customer issues, including participation in an off-hours on-call rotation
Optimize database queries using indexes and constraints
Apply least-privilege principles and understand timing attacks and encryption basics
Use LLMs for code review assistance, documentation drafting, and refactoring
Identify technical debt and propose roadmap focus areas
Present designs and technical tradeoffs to Product, DevSuccess, and Support
Influence technical decisions and support or lead architecture knowledge-sharing sessions
Join customer calls regarding technical topics and complex integrations
Write clear documentation for shipped features
Report to the Engineering Manager

Requirements

What you’ll need

8-10 years of professional software development experience
Demonstrated ownership of complex features from design through release
Bachelor's degree in computer science, or demonstrable experience with a broad set of theoretical topics
Advanced Java skills, including threading, concurrency, and performance profiling
Strong object-oriented design and implementation skills
Solid understanding of HTTP, TCP/IP, REST, and related protocols
Working knowledge of relational databases, query optimization, indexing strategy, and schema design
Experience designing test approaches for complex features and writing end-to-end tests
Comfortable working across cloud infrastructure, backend services, and JavaScript frontend development
Comfortable using Claude Code or comparable AI-assisted development tools
Local Denver metro candidates preferred and able to work onsite 1-2 days per week, or willing to travel to the office approximately once per quarter
Preferred: highly available distributed systems, OAuth 2.x, OIDC, enterprise authentication integrations, Kubernetes, Helm, GitHub Actions or comparable CI/CD
Must be authorized to work for any employer in the U.S.; visa sponsorship unavailable

Benefits

Comp & perks

Newly upgraded amenity spaces including a tenant lounge and café
Fitness studio, showers, lockers, and secure bike storage
Stocked in-suite kitchen with snacks and beverages
Onsite café with fresh, locally sourced, organic, and non-GMO options
3-acres of green space with parks, picnic areas, and recreation trails
Yoga and wellness programs
Dedicated outdoor workspaces and patio gathering areas
On-site parking, freeway access, and high-speed fiber internet
Sustainability-minded campus and community initiatives
Comprehensive medical, dental, and vision insurance, with the company covering the majority of medical premiums
Fully employer-paid HDHP option with HSA and employer contributions
Company-paid basic life insurance and short- and long-term disability coverage
Voluntary life insurance options
Healthcare and Dependent Care FSAs
401(k) plan with company match
Generous PTO and paid company holidays
Employee Assistance Program with confidential counseling and support
Professional growth and development opportunities
Eligibility for performance-based bonuses or variable compensation
Reimbursement of reasonable travel and lodging expenses for onsite interviews