Software Engineer, Network Simulation

Technical lead for an eBPF-based internet simulation platform: design kernel-space XDP/TC simulation, build control-plane topology database, architect lightweight in-range agents, enable runtime topology updates, mentor engineers, and drive architecture and operational integration for multi-tenant cyber range deployments., We are looking for a Senior Software Engineer to serve as the technical lead for SimSpace’s internet simulation platform - the system that makes cyber range environments behave like the real internet at the network layer. This is foundational, novel work: you will be designing and building a kernel-level simulation layer that reproduces the observable behavior of worldwide internet routing - correct ASN topology, realistic inter-AS latency, accurate traceroute and MTR output - without instantiating a single virtual router.

The approach is grounded in a patent pending eBPF-based architecture developed at SimSpace, and this role will take that proof of concept into a production-grade system. As the technical lead on a newly formed team, you will set architectural direction, mentor peer engineers, and partner closely with a Principal Engineer and your Engineering Manager to build something that does not yet exist at this fidelity in the industry.

The team is responsible for:

• A persistent, control-plane internet simulation service that serves multiple concurrent cyber ranges without per-range instantiation
• An eBPF-based network simulation layer providing geographically accurate ASN routing, inter-AS latency enforcement, and traceroute and MTR fidelity entirely in kernel space
• Lightweight in-range proxy agents that receive topology configuration from the control plane and handle local packet interception without requiring a full simulation stack in every range
• A topology database encoding real-world ASN-to-CIDR mappings, inter-AS latency models, and geographic placement data that drives the simulation
• Dynamic reconfiguration of the simulated internet topology at runtime without disrupting in-flight traffic

What will you be doing as a Senior Software Engineer, Network Simulation at SimSpace?

• Own the end-to-end architecture of the eBPF-based routing simulation layer, including XDP and TC hook point design, BPF map structure, and synthetic ICMP TTL-exceeded generation that makes traceroute and MTR behave correctly against the simulated topology
• Design and build the control-plane topology database and the pipeline that compiles real-world internet topology data into a form that in-range agents can consume and apply
• Architect the in-range proxy agent: the lightweight component that bridges the persistent control plane to individual cyber ranges, applying topology configuration locally and handling DNS delegation and traffic forwarding
• Define the interface contract between the control plane and in-range agents, including topology update propagation, graceful degradation when control plane connectivity is interrupted, and agent lifecycle management
• Serve as technical lead for the team - making daily architectural decisions across the full service scope, conducting design reviews, and maintaining engineering quality across all four engineering roles on the team
• Partner with other Engineers on novel simulation challenges, bring independent judgment to architectural tradeoffs, and shape the technical roadmap
• Mentor engineers on the team, raising the bar on systems design, kernel-level debugging, and engineering rigor
• Collaborate with adjacent platform teams on the operational model for a long-lived, multi-tenant service serving active cyber range deployments

Our Tech Stack:

Typescript, React, Postgres, Kotlin, Kubernetes, Spring Boot

• Deep expertise in Linux kernel networking and eBPF program development, including XDP, TC hooks, BPF map types, and the tradeoffs involved in kernel-space packet processing
• Strong systems programming skills - C or Rust for eBPF program development, and Go or Python for the control-plane agent and tooling layer
• Solid understanding of real-world internet routing - BGP, ASN topology, CIDR allocation, inter-AS peering - sufficient to model it faithfully without running routing software
• Experience designing systems with well-defined control plane and data plane separation, particularly where distributed components may have intermittent connectivity to a central controller
• Demonstrated technical leadership: you have set architectural direction and driven engineering quality across a team, whether as a tech lead, principal, or senior-plus individual contributor
• Comfort at the intersection of research and production engineering - this role involves taking a proof of concept and building it into something that runs reliably at scale
• Familiarity with Kubernetes as the deployment environment for both control plane services and distributed agent components
• Experience with network simulation, traffic shaping, or cyber range infrastructure is a strong plus
• Prior work in cybersecurity, defense, or government-adjacent environments is a plus due to SimSpace’s customer base

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.
• Flexible Time Off. Take the time you need with unlimited vacation and dedicated health & wellness days. SimSpace provides flexible solutions to meet the diverse work-life needs of team members.
• 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 fitness 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., An Hour Ago Remote or Hybrid 109K-150K Annually Senior level 109K-150K Annually Senior level Big Data * Food * Hardware * Machine Learning * Retail * Automation * Manufacturing Partner with business leaders to execute the analytics agenda, develop custom models and algorithms to uncover trends, identify and manage external partners, and deploy analytical approaches across a complex, matrixed organization to drive long-term business impact. Square, 123K-223K Annually Mid level 123K-223K Annually Mid level eCommerce * Fintech * Hardware * Payments * Software * Financial Services Field-driven Territory Account Executive responsible for full-cycle sales: 80% in-market activity with 50-60 weekly visits, self-sourced pipeline, demos, closing deals across Square products, building partnerships and vertical expertise, tracking activity in Salesforce, and consistently exceeding quota. Top Skills: AfterpaySalesforceSquare Square, 136K-245K Annually Senior level 136K-245K Annually Senior level eCommerce * Fintech * Hardware * Payments * Software * Financial Services Lead end-to-end strategy and execution for Tier 1 trade shows and industry events in retail and food & beverage. Own event selection, budget management, ROI tracking, booth design/production, vendor relationships, lead capture processes, cross-functional alignment, and inventory/shipping logistics. Travel to key events (up to 25%) and collaborate with sales, creative, product, and partners to drive qualified leads and showcase Square solutions.

What you need to know about the Colorado Tech Scene

With a business-friendly climate and research universities like CU Boulder and Colorado State, Colorado has made a name for itself as a startup ecosystem. The state boasts a skilled workforce and high quality of life thanks to its affordable housing, vibrant cultural scene and unparalleled opportunities for outdoor recreation. Colorado is also home to the National Renewable Energy Laboratory, helping cement its status as a hub for renewable energy innovation.

Key Facts About Colorado Tech

• Number of Tech Workers: 260,000; 8.5% of overall workforce (2024 CompTIA survey)
• Major Tech Employers: Lockheed Martin, Century Link, Comcast, BAE Systems, Level 3
• Key Industries: Software, artificial intelligence, aerospace, e-commerce, fintech, healthtech
• Funding Landscape: $4.9 billion in VC funding in 2024 (Pitchbook)
• Notable Investors: Access Venture Partners, Ridgeline Ventures, Techstars, Blackhorn Ventures
• Research Centers and Universities: Colorado School of Mines, University of Colorado Boulder, University of Denver, Colorado State University, Mesa Laboratory, Space Science Institute, National Center for Atmospheric Research, National Renewable Energy Laboratory, Gottlieb Institute

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.