Software Engineer - Fullstack

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!

Feature Team | React, Kotlin/Spring Boot, Kubernetes | AI Development

SimSpace is looking for a Senior Full Stack Engineer to join a feature team building production functionality across our platform. This role is backend-leaning, approximately 70% backend and 30% frontend, with work spanning APIs, services, data models, integrations, and React-based user workflows.

We are looking for an engineer who can own features end to end, use AI coding agents as a primary implementation tool, and still apply strong senior engineering judgment to architecture, code quality, testing, security, and production reliability.

What You Will Do

• Own features from requirements through implementation, testing, release, and production support.

• Build backend services, APIs, business logic, data integrations, and persistence layers using Kotlin, Spring Boot, PostgreSQL, and related technologies.

• Build and evolve React and TypeScript interfaces that complete user workflows and expose backend capabilities clearly.

• Work with Kubernetes-based environments and contribute to services designed for reliable deployment and operation.

• Use AI coding agents as a core part of delivery: prepare context, guide implementation, run tests, diagnose failures, refine code, and validate results.

• Review, understand, and take responsibility for AI-generated code before it ships.

• Collaborate with product, design, engineering, and QA to clarify acceptance criteria and deliver useful functionality.

• Design for maintainability, observability, security, performance, and reliable operation.

• Write meaningful automated tests and use CI/CD checks to prevent regressions.

• Help teammates improve their practical AI development workflows and code review practices.

Required Qualifications

• Senior-level software engineering experience delivering and maintaining production applications.

• Strong backend engineering fundamentals, including API design, object-oriented design, data modeling, persistence, error handling, testing, Git, and CI/CD.

• Hands-on experience with Java, Kotlin, Spring Boot, or comparable backend technologies.

• Practical experience with React and TypeScript for building complete user workflows.

• Experience working with REST APIs, microservices, and production data stores such as PostgreSQL.

• Comfortable working in Kubernetes or containerized deployment environments.

• A repeatable personal workflow for using AI coding agents to turn requirements into working, tested features.

• Ability to explain your AI-assisted development process with real examples: how you provide context, guide implementation, verify behavior, debug failures, and decide what to accept or rewrite.

• Strong ownership mindset: you can debug generated code, make independent technical decisions, and remain accountable for what ships.

Nonnegotiable AI Requirement

This role expects most feature implementation to be carried out with AI coding agents under your direction. Autocomplete, occasional prompting, or using AI only for code review is not enough.

You should be able to demonstrate a mature AI development workflow that connects requirements, code generation, execution, testing, debugging, and correction. The goal is not to outsource judgment to AI; the goal is to use AI to increase delivery speed while maintaining senior-level code quality and production responsibility.

Highly Desirable

• Experience with Kubernetes-native services, distributed systems, orchestration, or control-plane style APIs.

• Familiarity with networking fundamentals: DNS, TCP/IP, HTTP/TLS, ports, routing, and connectivity troubleshooting.

• Working knowledge of VMware virtualization or virtualized lab environments.

• Experience with event-driven systems, asynchronous workflows, message queues, or long-running operations.

• Experience helping a team adopt AI coding agents effectively without sacrificing quality.

• Familiarity with cybersecurity, simulation environments, SaaS integrations, or infrastructure-heavy products.

Tech Stack

Our current stack includes:

• Kotlin, Spring Boot, Java

• TypeScript, React

• PostgreSQL

• REST APIs and microservices

• Kubernetes and containerized services

• Git, CI/CD, automated testing

• AI coding agents and shared development harnesses

Interview Expectations

During the interview process, expect to discuss and possibly demonstrate how you use AI agents to build production software. We will ask about real examples, your workflow, your debugging process, how you validate generated code, and how you decide when to intervene manually.

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.