Software Engineer

Subcritical Systems Inc; Austin (TX); On-site; USD 120,000 - 170,000; Full time

Benefits offered by this job

Health insurance

Job summary

Subcritical Systems Inc. seeks a core contributor for a five-person engineering team focused on CAD automation tooling that accelerates the design-to-construction pipeline.

You will integrate AI tools, solve geometry and data-modeling challenges, and own major portions of the software stack end-to-end. In this role you will design automation pipelines that engineers rely on daily and help ensure construction schedules stay on track.

Qualifications

• Strong software engineering fundamentals: Python and/or TypeScript, clean architecture, version control, testing.
• Hands-on experience integrating frontier AI models into production workflows: model APIs, agentic systems (LangChain, LangGraph, or similar).
• Experience building tools used by domain experts (engineers, scientists, designers).
• Comfort working with geometry, spatial data, or engineering file formats (CAD, STEP, mesh).
• Track record of shipping in resource-constrained environments (startup, early-stage team).
• Excellent communication with non-software collaborators.
• High agency: identify problems, propose solutions, and execute without a detailed spec.

Responsibilities

• Develop and maintain our in-house CAD automation pipeline, part of the ATLAS platform, generating parametric 3D assemblies.
• Build interfaces between the design toolchain and standard engineering formats (STEP, IGES).
• Automate physics simulation workflows: Monte Carlo neutronics, EM solvers, thermal analysis, parameter sweeps.
• Own core pieces of ATLAS: orchestration, retrieval, tool gateways, evaluation and tracing for reliability.
• Build the design task management layer linking engineering tasks to the master construction schedule.
• Contribute to internal tooling: VCS for design artifacts, validation, and documentation generation.
• Collaborate daily with mechanical designers and nuclear engineers to translate constraints into software.

Skills

Python/TypeScript

AI model integration

Domain expert tooling

Geometry/Spatial data

Startup experience

Communication

High agency

Tools

OpenCascade

FreeCAD

Fusion 360

SolidWorks

Job description

You will be a core contributor on a five-person engineering team building the internal tooling that speeds up our design-to-construction pipeline. Your main focus is our CAD automation platform: a system that generates and validates complex 3D assemblies programmatically, so our mechanical designers and engineers can iterate far faster than traditional CAD workflows allow. You will integrate AI tools into this workflow, solve hard geometry and data modeling problems, and own major parts of the software stack end to end. Success in the first 90 days looks like design automation pipelines our engineers rely on daily and a construction schedule that stays on track because of them.

KEY RESPONSIBILITIES

• Develop and maintain our in-house CAD automation pipeline, which is a part of our ATLAS platform. This pipeline generates parametric 3D assemblies (geometry, tolerances, bill of materials) from structured design inputs.
• Build software interfaces between our design toolchain and standard engineering formats (STEP, IGES, manufacturing packages) for handoff to construction and fabrication partners.
• Automate physics simulation workflows: pipelines that set up runs (Monte Carlo neutronics, electromagnetic solvers, thermal analysis, parameter sweeps), queue them on our compute, parse solver output, and feed results back into design iteration. Today much of this is manual; your job is to make it push-button.
• Own core pieces of ATLAS, our multi-agent AI platform: orchestration and agent delegation, retrieval over engineering and regulatory document corpora, tool gateways, and evaluation and tracing so we can trust what the system produces.
• Build the design task management layer that connects individual engineering tasks to the master construction schedule, with dependency tracking and two-way sync to our project management tools.
• Contribute to internal tooling infrastructure: version control for design artifacts, automated validation and consistency checking, and documentation generation.
• Collaborate daily with mechanical designers and nuclear engineers: translate physical constraints into software logic, and surface software capabilities that open up new design approaches.

QUALIFICATIONS

Required

• Strong software engineering fundamentals: Python and/or TypeScript, clean architecture, version control, testing.
• Hands-on experience integrating frontier AI models into production workflows: model APIs, agentic systems (LangChain, LangGraph, or similar), retrieval and context management, evals, observability, and the surrounding infrastructure required to deploy reliable AI-enabled products.
• Experience building tools used by domain experts (engineers, scientists, designers). You know how to translate expert knowledge into reliable software.
• Comfort working with geometry, spatial data, or engineering file formats (CAD, STEP, mesh, simulation outputs).
• Track record of shipping in resource-constrained environments: startup, early-stage team, or solo ownership of a complex system.
• Excellent communication with non-software collaborators. You can explain a technical constraint to a mechanical engineer and absorb domain knowledge quickly.
• High agency: you identify problems, propose solutions, and execute without needing a detailed spec.

Preferred

• Experience as an early technical hire at a deep-tech, hardware, or engineering-software startup.
• Background in or exposure to mechanical engineering, manufacturing, or technical design review processes.
• Experience with CAD systems (OpenCascade, FreeCAD, Fusion, SolidWorks, or similar) or geometric modeling libraries.
• Prior work on systems with physical-world consequences: robotics, aerospace, energy, biotech, advanced manufacturing.

BENEFITS

We offer health, dental, and vision insurance

LOCATION & WORK POLICY

This role is fully in person in Austin, Texas. Our facility is located next to Austin Airport.