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