Senior Fullstack Engineer

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 Senior Full Stack Engineer to build the operator experience for SimSpace’s internet simulation platform. This engineer will turn the platform’s control-plane capabilities into intuitive workflows for configuring simulated services, registering personas, managing topology, provisioning applications, integrating ranges, and monitoring platform state.

The role will work closely with the backend engineer who owns the control-plane API, event-driven orchestration, persistence, and deployment model. While the primary focus will be building the frontend experience in React and TypeScript, this engineer will also contribute to backend services and integration layers where needed. The ideal candidate is comfortable moving across the stack, translating complex distributed-system behavior into clear user experiences, and building interfaces that remain understandable when operations are asynchronous, long-running, or partially successful.

What you will help build

• The web-based operator experience for configuring and managing the internet simulation platform across multiple ranges and environments

• React and TypeScript workflows for creating services, registering personas, managing topology, provisioning simulated SaaS applications, delivering scenario content, and querying platform state

• Reusable frontend architecture, components, and design patterns that support a growing collection of platform capabilities

• Integration between the frontend and the control-plane API, including authentication, authorization, validation, error handling, asynchronous operations, and real-time status updates

• Operational views that make platform state, deployment health, range connectivity, failures, and recovery actions understandable to users

• Backend endpoints, service integrations, and supporting logic in collaboration with the engineer who owns the control plane

• Testing and delivery practices that allow the frontend and backend to evolve together without breaking operator workflows

What you will do

• Design and build the platform’s frontend using React and TypeScript, creating clear workflows for technically sophisticated operators

• Translate complex platform operations—such as standing up a range, registering a persona, provisioning a service, or updating topology—into intuitive, observable user experiences

• Build reusable components and frontend patterns for forms, resource configuration, status reporting, validation, error handling, and long-running operations

• Integrate the frontend with the control-plane API, ensuring API contracts are used consistently and failures are presented with enough context for users to understand and recover

• Partner with the backend engineer on API design so that frontend requirements, user workflows, and operational needs are reflected in the platform’s interfaces

• Contribute to backend services and integration layers where needed, including implementing supporting endpoints, evolving data models, and troubleshooting cross-stack issues

• Develop views for platform health, range connectivity, service lifecycle, operation history, and partial-failure recovery

• Implement appropriate state-management and data-fetching patterns for a multi-tenant platform with asynchronous and event-driven backend behavior

• Build automated tests across the frontend stack, including component, integration, and end-to-end coverage for critical operator workflows

• Improve frontend performance, accessibility, security, and maintainability as the product and engineering team grow

• Collaborate with product, design, backend, network simulation, and SRE partners to deliver cohesive features across the full platform

• Help establish frontend development standards, code-review practices, observability, release processes, and documentation for the user experience

Who you are:

• Strong experience building production web applications with React and TypeScript

• Experience designing and delivering complex operator interfaces, administrative consoles, infrastructure-management products, or other workflow-heavy applications

• Strong frontend architecture skills, including component design, application state management, data fetching, routing, forms, validation, and error handling

• Experience integrating frontend applications with RESTful or similar platform APIs

• An understanding of asynchronous and distributed-system behavior and the ability to represent long-running operations, partial failures, retries, and eventual consistency clearly in a user interface

• Backend development experience, preferably with Kotlin and Spring Boot, or the ability to become productive in that stack

• Experience collaborating on API schemas and contracts with backend engineers

• Strong testing practices across unit, component, integration, and end-to-end testing

• Familiarity with authentication, authorization, secrets handling, and secure frontend development

• Experience instrumenting applications so that failures can be diagnosed across browser, API, and backend service boundaries

• Strong product and user-experience instincts, particularly when simplifying technically complex workflows

• Clear communication skills and the ability to work closely with engineers across frontend, backend, infrastructure, and operations

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

• Compensation. Base monthly pay range: 1,500,000 CRC - 2,500,000 CRC reflecting our confidence in your expertise and impact, with the opportunity for annual bonuses tied to company performance and individual contributions.

  • Health & Wellness. Private medical, dental, vision, and life benefits.

  • Mental Health Support. Access to company-paid counseling, coaching, and resources for you and your family through Spring Health.

  • 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.

  • 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.

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.