Network Simulation SSE

Senior Software Engineer Network
Simulation @ SimSpace

About the Role
As a Senior Software Engineer Network Simulation youll serve as the technical lead for
SimSpaces internet-simulation platform the system that makes cyber-range environments
behave like the real internet at the network layer. This is foundational novel work: designing and
building a kernel-level simulation layer that reproduces worldwide internet routing (correct ASN
topology realistic inter-AS latency accurate traceroute/MTR output) without instantiating a single
virtual router grounded in a patent-pending eBPF architecture youll take from proof of concept to
a production-grade system.
SimSpace is an AI Proving Ground for cybersecurity a live-fire cyber range and simulation
platform trusted by allied governments militaries and Fortune 50 enterprises. Founded in 2015
by experts from U.S. Cyber Command and MIT Lincoln Laboratory SimSpace lets organizations
train test and validate their defenses (and now their AI tools) in a safe realistic environment
with a new platform reaching general availability in August 2026.
Key Responsibilities
Own the end-to-end architecture of the eBPF-based routing-simulation layer XDP/TC
hook-point design BPF map structure and synthetic ICMP TTL-exceeded generation so
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 in-range agents can consume.

Architect the lightweight in-range proxy agent that bridges the persistent control plane to
individual ranges applying topology locally and handling DNS delegation and traffic
forwarding.

Define the interface contract between the control plane and in-range agents topology-
update propagation graceful degradation on connectivity loss and agent lifecycle

management.
Serve as technical lead for the team making daily architectural decisions conducting
design reviews and maintaining engineering quality across the teams roles.
Partner with other engineers on novel simulation challenges bring independent judgment to
architectural tradeoffs and shape the technical roadmap.
Mentor engineers 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.

Required Qualifications
Strong bilingual proficiency in English and Spanish across written virtual and in-person
interactions.
Deep expertise in Linux kernel networking and eBPF program development XDP TC
hooks BPF map types and the tradeoffs of kernel-space packet processing.
Strong systems-programming skills C or Rust for eBPF development and Go or Python
for the control-plane agent and tooling.
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 clear control-plane / data-plane separation particularly
where distributed components have intermittent connectivity to a central controller.
Demonstrated technical leadership setting architectural direction and driving engineering
quality across a team (as tech lead principal or senior-plus IC).
Comfort at the intersection of research and production engineering taking a proof of
concept to something that runs reliably at scale.
Nice to Have
Familiarity with Kubernetes for deploying control-plane services and distributed agents.
Experience with network simulation traffic shaping or cyber-range infrastructure.
Prior work in cybersecurity defense or government-adjacent environments.
Our Tech Stack
TypeScript React Postgres Kotlin Kubernetes Spring Boot
Location & Work Setup
Remote-first based in Costa Rica. SimSpace operates remote-first with no designated office;
occasional in-region team gatherings (roughly once every few months) may occur and any
required travel is reimbursed. Youll collaborate with SimSpaces distributed teams (40 U.S.
states and Costa Rica) so reliable overlap with U.S. time zones and strong English
communication are expected.
Engagement begins through an Employer of Record (EOR) and is planned to convert to
SimSpaces local Costa Rica entity (anticipated around AugustSeptember 2026) at which point
you become a full-time SimSpace employee.
Compensation & Benefits

Base salary. Competitive level-based for a Senior Software Engineer / tech lead exact
USD range and payment currency to be confirmed with SimSpace with annual
performance bonuses tied to company and individual performance plus eligibility for the
corporate bonus plan.
Equity. Stock options at hire with annual performance-based grants.
Health & insurance. Company-paid private medical and life insurance premiums;
comprehensive medical dental and vision benefits.
Statutory. 13th-month payment (aguinaldo) per Costa Rican law.
Mental health. Company-paid counseling and coaching for you and your family via Spring
Health.
Parental leave. Paid leave plans.
Referral rewards. $1500$3500 for every qualified referral hire.
Continuous learning. LinkedIn Learning membership.
Connection. Monthly SocialSpace community reimbursements for time with teammates.