Backend Senior Software Engineer, Attack and User Emulation Team (AUE)

SimSpace serves as an AI Proving Ground where organizations can confidently train, test, and outmaneuver adversaries in any environment. Trusted by allied governments, militaries, enterprises, and research institutions worldwide, SimSpace enables adaptive, AI-ready defenses that stay ahead of evolving threats. Founded in 2015 by experts from U.S. Cyber Command and MIT Lincoln Laboratory, the platform unifies training, testing, and validation in a realistic, live-fire simulation—helping teams evaluate security investments, optimize performance, and compress cyber readiness cycles from months to days.

Why join SimSpace? We are an organization that is focused on building our culture and mindfully enhancing our atmosphere every day which is why we have collaborated on an integral value system. Our governing philosophy of being Human Centered is deeply embedded within our value system. We apply this philosophy to every one of our internal team members, external clients, and their customers.

How Do We Work? We believe that people are at the center of everything we do. SimSpace fosters a culture of continuous learning, curiosity, and professional growth. That belief shows up in action: in-house training, internal and external learning platforms, cyber conferences, industry events, and dedicated time for skill development. Our people are empowered to shape their careers - and it shows. Year over year, SimSpace consistently outperforms industry benchmarks in internal mobility, promotions, and total rewards growth.

Who Thrives Here? We are a team of innovators, protectors, and problem-solvers. We believe diversity of thought and experience fuels better solutions, and we’re committed to building teams that reflect the communities we serve. Whether you’re remote or office-based, you’ll collaborate with talented colleagues across departments and time zones, united by the mission to create a safer digital world.

We invite you to apply today!

We are looking for: a Backend Senior Software Engineer, Attack and User Emulation Team (AUE), you will serve as a primary technical leader driving the evolution of our core cyber range emulation platform. In this role, you will leverage deep expertise in microservices, event-driven messaging systems, Spring Boot, and containerization to architect and scale complex, distributed emulation services. These high-impact systems enable our users to simulate real-world cyber attacks and user personas with high fidelity and realism.

As a Senior Software Engineer, AUE, you will help shape the integration of AI-assisted capabilities into the platform. You will design scalable, secure patterns for coordinating AI-enabled services and workflows so that attack and user emulations can become more dynamic, autonomous, and responsive. You may evaluate and adopt emerging interoperability approaches, including Model Context Protocol (MCP) and Agent-to-Agent (A2A) protocol, as the platform evolves.

Your reach extends beyond feature delivery. You will own the long-term technical vision and architecture for critical platform capabilities, drive engineering excellence across teams, and act as a multiplier by mentoring engineers and shaping team strategy. You will balance strategic architectural design with hands-on code delivery, solving complex, high-risk technical problems.

What will you be doing as our Senior Software Engineer, AUE:

• Architectural Leadership & Execution: Architect, design, and deliver highly scalable, fault-tolerant, and resilient distributed microservices for cybersecurity range simulations, setting technical standards across systems.
• AI & Agent Infrastructure: Design and implement platform capabilities that coordinate AI-enabled services and autonomous workflows to support intelligent emulation behaviors, reliable context exchange, and clear operational controls. You will evaluate and adopt appropriate interoperability patterns and protocols as the platform evolves.
• Cross-Functional & Strategic Ownership: Partner closely with Product Managers, UX Designers, and Engineering Leadership to define roadmap priorities, decompose multi-quarter initiatives into actionable technical milestones, and lead complex end-to-end execution.
• Technical Excellence & Standards: Drive system reliability, performance tuning, and fault tolerance strategies. Establish and champion best practices in code quality, testing methodologies, API design, and system architecture across the team.
• Mentorship & Talent Development: Mentor and coach engineers across levels, actively supporting their growth through regular design reviews, code reviews, constructive feedback, and delegation of high-impact technical initiatives.
• Operational Maturity & Observability: Design and implement robust observability, telemetry, and proactive alerting frameworks to ensure high availability, fast incident resolution, and zero-downtime deployments.
• Security-First Engineering: Embed security, compliance, and offensive/defensive mitigation patterns directly into system design and the software development lifecycle.
• Knowledge Sharing & System Design: Author and maintain architectural decision records (ADRs), technical spec documents, and system design patterns to align teams and build long-term organizational knowledge.

What are the qualifications to apply? To be successful as a Senior Software Engineer, AUE, you need to have:

• 4+ years of hands-on software development experience with a track record of architecting, building, and operating large-scale, distributed microservices in production.
• 2 year degree in science & technology or commensurate experience.
• Deep Expertise in OOP languages such as Java or Kotlin, with proven experience in advanced API design, system integration, and event-driven architectures.
• Production Expertise in container orchestration platforms (Kubernetes, Docker) and enterprise frameworks (Spring Boot).
• AI & Agent Systems Integration: Experience integrating AI/LLM capabilities into production software systems, with sound judgment around service boundaries, context management, reliability, security, and observability. Experience with agentic workflows, orchestration systems, Model Context Protocol (MCP), or Agent-to-Agent (A2A) communication patterns is a plus.
• Proven Track Record of leading complex, multi-system initiatives from ideation to delivery, making sound pragmatic trade-offs between speed, scalability, and technical debt.
• Domain Context: Strong understanding of cybersecurity concepts, including offensive/defensive tactics, user emulation techniques, or threat landscapes.
• Advanced Problem Solving: Experience identifying system bottlenecks, improving fault tolerance, and resolving complex distributed systems failures.

Bonus / Nice-to-Have Qualifications:

• Experience evaluating or integrating AI or machine learning capabilities into production backend systems, particularly when model-driven behavior must be reliable, observable, and safely controlled.
• Exposure to Reinforcement Learning (RL) concepts (e.g., reward functions, policy optimization, or multi-agent RL environments), particularly applied to decision-making or simulation modeling.

Who you are:

• A Technical Leader & Multiplier: You naturally drive strategic initiatives, elevate those around you, and foster a culture of technical rigor, accountability, and continuous improvement.
• An Innovative AI Practitioner: You are excited about the frontier of agentic AI and eager to integrate technologies like MCP, agent workflows, and ML/RL techniques to push the boundary of realism in cyber emulation.
• Collaborative & Pragmatic Architect: You excel at breaking down ambiguous problems into manageable solutions and balancing technical perfection with business delivery goals.
• Growth-Minded & Open: You embrace continuous feedback, enjoy mentoring colleagues, and foster psychological safety through constructive, honest collaboration.
• Outcome & Systems-Focused: You are driven by impact and customer outcomes, building reusable, maintainable systems that scale seamlessly with business growth.
• Cybersecurity Enthusiast: You bring domain interest or hands-on experience in security platforms and love solving challenges unique to cyber simulation.

Our Tech Stack:

• Languages: Kotlin, Java, Python, Go
• Frameworks & Infrastructure: Spring Boot, Kubernetes, Docker, VMware
• Architecture: Microservices, Event-Driven Systems, Distributed Messaging

We’re proud to offer a competitive and comprehensive package designed to support your well-being, growth, and success:

• Compensation. Base salary range: $160,000 – $225,000, reflecting our confidence in your expertise and impact, with the opportunity for annual bonuses tied to company performance and individual contributions.
• Health & Wellness. Comprehensive medical, dental, and vision benefits, plus savings plans—coverage starts on day one!
• Mental Health Support. Access to company-paid counseling, coaching, and resources for you and your family through Spring Health.
• Financial Well-Being. Plan for your future with a 401(k)-retirement savings plan featuring a company match.
• Parental Leave. Paid leave plans to support you and your loved ones during life’s most important moments.
• Ownership Opportunities: Equity stock options at hire, with annual performance-based grants—become an invested stakeholder in our shared success.
• Referral Rewards: Earn $1,500–$3,500 for every qualified hire through our employee referral program.
• Peloton Interactive Wellness Program: Full- and partial- subsidized membership plans and equipment discounts to help you reach your personalized wellness goals.
• Continuous Learning: Access a LinkedIn Learning membership to prioritize your personal and professional development.
• Social Connections: Monthly reimbursements for meaningful connections with teammates through our SocialSpace Community.
• Extra Perks: Legal plan coverage, pet insurance, wellness reimbursements, and more to simplify life’s details.

SimSpace is an Equal Opportunity Employer:

In compliance with federal law, all persons hired will be required to verify identity and eligibility to work in the United States and to complete the required employment eligibility verification document form upon hire.

SimSpace is an Equal Opportunity Employer. All qualified applicants will receive consideration for employment without regard to race, color, religion, sex, sexual orientation, gender identity, national origin, age, pregnancy, genetic information, disability, status as a protected veteran, or any other protected category under applicable federal, state, and local laws. We are committed to providing an inclusive and welcoming environment for all members of our staff, clients, volunteers, subcontractors, vendors, and clients.

Research shows that women and people from underrepresented groups only apply to jobs if they meet all of the qualifications. However, no one ever meets 100% of the qualifications. SimSpace encourages you to break that statistic and to apply. We look forward to your application!

We also consider qualified applicants regardless of criminal histories, in accordance with applicable law. We are committed to providing reasonable accommodations for qualified individuals with disabilities in our job application procedures. If you need assistance or accommodation due to a disability, please contact careers@simspace.com.

SimSpace does not accept unsolicited resumes from employment agencies.

Actual compensation for the position is based on a variety of factors, including, but not limited to affordability, skills, qualifications and experience, and may vary from the range.