Staff Software Engineer in Test (Modeling and Simulation) at Code Metal · LumiJobs

Responsibilities

Code Metal is strengthening its Quality Engineering capabilities to make software quality more measurable, repeatable, and actionable. We are seeking a founding Staff Quality Engineer (SDET) for Modeling & Simulation, within the centralized Quality Engineering function.
Our Modeling & Simulation team builds wargaming and decision-support platform that helps the U.S. Department of War (DoW) evaluate mission- and campaign-level force-design decisions. The system combines backend APIs, asynchronous workers, geospatial and sensing models, authenticated multi-team play (including fog of war), external simulation integrations, and emerging AI-assisted capabilities.
The platform already has automated unit and integration coverage, but its growing combination of distributed services, stateful simulation, external integrations, probabilistic behavior, and high-consequence user workflows requires a more systematic validation architecture. This role will connect and extend that foundation into reproducible quality evidence across services, models, and end-to-end workflows.
Core Responsibilities
Translate Quality Engineering strategy into a risk-based validation approach for Modeling & Simulation across unit, integration, contract, end-to-end, performance, resilience, and security-critical workflows.
Build reliable test infrastructure, including deterministic fixtures, isolated test data, service and event-contract tests, integration harnesses, versioned reference scenarios, deterministic replay, and focused browser automation for critical user journeys.
Improve CI feedback through effective test partitioning, parallel execution, caching, failure attribution, and flaky-test control, in partnership with shared platform owners.
Write behavior-focused tests for high-risk planning, sensing, simulation, authorization, state-transition, and recovery workflows.
Partner with simulation and model owners to turn intended behavior, assumptions, and known limitations into reusable reference scenarios, regression baselines, characterization or differential tests, and reproducible quality evidence.
Define validation and release criteria for simulation and emerging AI-assisted workflows, combining deterministic assertions, contracts, reference checks, statistical or model-based evaluation, failure-recovery testing, and appropriate human oversight.
Establish repeatable performance and reliability validation with measurable objectives and clear release evidence.
Participate in design and code reviews, identify testability risks early, and mentor engineers in testing complex simulation, distributed-system, and AI-assisted changes without becoming an approval bottleneck.

Qualification

Significant experience as an SDETAbility to set technical directionExperience validating simulationExperience with performance testingExperience testing cloud-based

Required

Significant experience as an SDET, test-infrastructure engineer, quality architect, or software engineer responsible for automated validation of production systems.
Strong production programming skills in Python.
Deep experience building Python test infrastructure using pytest or comparable frameworks, including asynchronous testing, fixtures and factories, parallel execution, and CI integration.
Demonstrated experience designing risk-based test strategies across multiple layers of a distributed system.
Experience validating complex systems with partially nondeterministic behavior, such as simulation, statistical models, ML, or AI-assisted workflows, and sound judgment about deterministic checks, reference evidence, statistical evaluation, and human oversight.
Hands-on experience testing Docker-based or comparable containerized, multi-service applications, including APIs, databases, messaging, authentication, authorization, and data isolation.
Experience building and improving CI workflows with GitHub Actions or a comparable platform, including test isolation, failure diagnosis, and flaky-test control.
Ability to set technical direction, write design documents, mentor engineers, and lead multi-team initiatives through influence.

Preferred

Experience validating simulation, geospatial, event-driven, or other stateful systems, including reproducible deterministic and probabilistic behavior.
Familiarity with testing or debugging C++ simulation or systems code.
Experience testing TypeScript and React applications with Playwright or equivalent tools.
Experience with performance testing, generated test data, and API or schema validation.
Experience testing cloud-based, containerized systems using logs, metrics, traces, and retained test artifacts.
Familiarity with constructive simulation, distributed simulation standards, or mission-analysis software.
Hands-on experience evaluating AI-assisted or agentic systems, including tool-calling or multi-step workflows, and understanding risks such as nondeterminism, unsupported outputs, prompt or context manipulation, unsafe tool use, hidden state, and silent failure.
Experience using AI coding assistants or agents throughout the software development lifecycle and defining quality controls for AI-assisted changes, such as scoped workflows, independently verifiable tests, human code review, CI checks, and risk-based release evidence.

Staff Software Engineer in Test (Modeling and Simulation)

Responsibilities

Qualification

Required

Preferred

Benefits

Company

Code Metal

More roles at Code Metal