Backend Software Engineer - Simulations

Mosaic.tech; New York (NY); On-site; USD 120,000 - 160,000; Full time

Benefits offered by this job

Full medical/dental/vision plans

401(k) retirement plan

Commuter benefits

On-site gym

Job summary

Rune Technologies builds mission‑critical software for military logistics. As a Backend Software Engineer focused on Simulations, you will own the TyrOS forecaster and related models, working with arithmetic and physics‑based reasoning to produce reliable production systems.

You will collaborate with a cross‑functional team to integrate simulations into operational workflows, tackle complex forecasting problems, and deliver software that directly supports warfighter sustainment in dynamic

Qualifications

• 4+ years of software engineering in scientifically or mathematically complex domains.
• Ability to work with mathematical models and numerical methods in code.
• Proficiency in Python, C++, or Go.
• Production-grade engineering mindset; not purely research.
• Math or science background via degree or professional experience.
• Strong sense of ownership and bias for action.

Responsibilities

• Build and own production-grade simulation and forecasting software with a focus on the forecaster.
• Work with mathematical models, numerical methods, and scientific formulas in code.
• Collaborate with forecaster lead and platform team to integrate simulations into TyrOS.
• Engage in design discussions and code reviews to ensure engineering rigor.
• Triage and debug production issues for reliability and rapid iteration.
• Collaborate with engineers, PMs, and military stakeholders to meet requirements.

Skills

Python

C++

Go

Mathematics

Simulation

Ownership

Education

Math/Science degree

Graduate work in science

Tools

NumPy/SciPy

AWS/Kubernetes

Simulation libraries

Job description

About Rune

Rune Technologies builds mission-critical software for military logistics and sustainment. Our flagship product is TyrOS, an AI-enabled logistics command and control platform that gives commanders a single, real-time operating picture of their sustainment fight, from inventory and distribution to medical and operational planning, even in degraded and contested environments.

We're not a traditional defense contractor. We're a small, fast-moving team that combines deep operational experience in and with the DoD with the software discipline of the best product companies, and we apply that combination to a customer set that desperately needs it. We stay close to our users by embedding directly with military units during exercises and rotations, and we ship constantly based on what we learn.

The U.S. military and its allies face a real logistics modernization problem. We're building the software to solve it.

About the Role

At Rune Technologies, we are building the logistics technology backbone that the U.S. and allied militaries need to dominate in large-scale combat operations. As a Backend Software Engineer at Rune, you will be part of a high-impact team working at the intersection of advanced logistics algorithms, modern AI-enabled software, and complex system integrations — all in support of the warfighter at the tactical edge.

You'll join us in our mission to bring 21st-century software to the sustainment domain: modernizing inventory management, transportation optimization, and predictive planning with state-of-the-art user experiences. You'll work closely with a team of experienced engineers, product designers, and operational experts who care deeply about delivering real-world impact.

As our Backend Software Engineer for Simulations, you will own the simulations workstream within TyrOS, working closely with our forecaster lead and the broader platform team. The primary focus is Rune's forecasting system, building the production software that models, predicts, and reasons about logistics outcomes in complex operational environments. This role calls for a strong software engineer who is also mathematically and scientifically fluent: someone who can work in formulas, reason about physical systems, and build production-quality software around that reasoning.

What You'll Do

• Build and own production-grade simulation and forecasting software, with a primary focus on Rune's logistics forecaster.
• Work with mathematical models, numerical methods, and scientific formulas to implement software where correctness is defined by the underlying physics or math, not just user acceptance.
• Collaborate closely with the forecaster lead and platform team to integrate simulation capabilities into TyrOS workflows.
• Participate in technical design discussions and code reviews, contributing to a culture of engineering rigor and mission focus.
• Triage and debug issues in production, ensuring reliability and rapid iteration in support of operational needs.
• Work closely with engineers, product managers, and military stakeholders to ensure simulation and forecasting systems meet real-world sustainment requirements.

Qualifications

• 4+ years of experience in software engineering, with demonstrated experience building software in a scientifically or mathematically complex domain: sensor algorithms, motion planning, simulation, forecasting, or similar.
• Ability to work with mathematical models and numerical methods in code; comfort reasoning about correctness in terms of physics or math, not just software behavior.
• Proficiency in Python, C++, or Go.
• Strong software engineering foundation — this role requires production-quality engineering, not analysis or research.
• Math or science background, through degree, graduate work, or professional domain experience.
• Strong sense of ownership and a bias for action.

Desired Qualifications

• Experience at a defense‑adjacent autonomous systems company in a hands‑on engineering capacity.
• Degree or graduate degree in a scientific field such as physics, applied mathematics, aerospace, or mechanical engineering.
• Familiarity with numerical simulation frameworks or scientific computing libraries.
• Experience deploying software to production environments, including cloud (AWS, Kubernetes) and edge infrastructure.

Benefits

Rune offers top‑tier benefits for full‑time employees to include a full suite of insurance options at no cost for employees and low‑cost to spouses and dependents. Highly competitive equity grants are also included in the majority of full‑time offers and are considered part of Rune's total compensation package. Benefits include:

• Comprehensive medical, dental, and vision plans; premiums 100% covered by Rune for all employees; exceptionally low premiums for spouses and dependents.
• Basic life insurance and disability 100% covered for all employees by Rune; option to purchase additional life insurance available.
• 'Take the time off that you need, when you need it' paid time off, not accrual based.
• Generous company holiday calendar including a holiday shutdown in December.
• Supportive leave of absence program including time off for military service, medical events, and parental leave.
• Full 401(k) retirement plan for all full‑time eligible employees.
• Company‑funded commuter benefits.
• Free access to on‑site gym at office.