Process Modeling Engineer (Founding Team)

Riven Systems; New York (NY); On-site; USD 160,000 - 200,000; Full time

Job summary

Riven Systems in New York, NY, is seeking a Process Modeling Engineer to bridge our platform with operating plants. You will collaborate with experts in thermodynamics, hydrometallurgy, ML, and autonomous experimentation to model flowsheets with industry-leading rigor.

You will build a scalable, composable modeling layer, ensure robust initialization and convergence, and connect process models to thermodynamic calculations.

Qualifications

• Ph.D. or equivalent industry experience in chemical engineering or related field.
• Experience building process models and diagnosing convergence failures.
• Fluency with equation-oriented modeling and large-scale nonlinear optimization.
• Knowledge of hydrometallurgical unit operations or comparable separations.
• Ability to work across interdisciplinary teams and communicate clearly.

Responsibilities

• Develop the programmatic process modeling layer for models to be written by humans or agents.
• Design a composable model architecture with rigorous flowsheet validation.
• Systematize initialization, scaling, and solving of process models.
• Connect the process layer to thermodynamic modeling.
• Build data paths from pilots and customer deployments into the platform.
• Establish continuous validation and regression testing across the model library.

Skills

Equation-oriented modeling

Nonlinear optimization

Hydrometallurgy knowledge

Software system design

Interdisciplinary communication

High agency and initiative

Pilot/plant experience

Validation mindset

Education

Ph.D. in Chemical Engineering or related field

Tools

Aspen Plus

gPROMS

METSIM

OLI

IDAES/PrOMMiS

Job description

About Riven

Our mission is to leverage fundamental science and the exponential growth of computational power to revolutionize industrial chemistry. We are integrating autonomous laboratories, computational modeling, and AI to systematize the design, de-risking, and deployment of new chemical capabilities. Our work is deeply interdisciplinary and closes the loop between fundamental physics and industrial deployment.

We are starting with critical minerals because they underpin virtually every facet of modern life—including energy infrastructure, compute architecture, and defense systems—and are at the heart of a generational effort to reindustrialize the west. We intend to dramatically reduce the time and cost required to scale new mineral processing capacity.

About the role

As a Process Modeling Engineer you will build the layer that connects Riven's platform to operating plants. You will work closely with experts in thermodynamics, hydrometallurgy, machine learning, and autonomous experimentation to model flowsheets at a level of rigor the industry cannot currently reach.

Riven is hiring a lean, interdisciplinary team and experience spanning multiple roles is welcome. Apply to whichever role is closest to your skillset.

Initial Responsibilities

• Develop Riven's programmatic process modeling layer where models can be written by humans or agents.

• Design a composable model architecture with rigorous flowsheet validation.

• Systematize the initialization, scaling, and solving of process models.

• Connect the process layer to thermodynamic modeling.

• Build the paths that carry operational data from pilots and customer deployments back into the platform.

• Establish continuous validation and regression testing across a growing model library.

Qualifications

• Ph.D. in Chemical Engineering, Operations Research, or a related field, or equivalent industry experience.

• Experience building process models, including writing unit operation models and diagnosing convergence failures.

• Fluency with equation-oriented modeling and large-scale nonlinear optimization, including initialization, scaling, and degrees of freedom.

• Working knowledge of hydrometallurgical unit operations, or comparable separations experience.

• Views on how process modeling changes when the caller is an agent rather than an engineer at a terminal.

• Comfortable with the tools and processes for building large software systems.

• Clear interdisciplinary communication and the curiosity to quickly learn and execute in new domains.

• Ability to prioritize, execute, and collaborate with a high degree of agency, a willingness to be wrong, and the ambition to build something that has never existed before.

• Trust, humor, rigor, and an excitement to work in a scrappy, interdisciplinary early-stage environment.

Bonus Points

• Deep experience with commercial or open-source simulators (Aspen Plus, gPROMS, METSIM, OLI, IDAES/PrOMMiS) and a clear view of where they fall short.

• Contributions to open-source process modeling or optimization tooling.

• Dynamic simulation, in-flowsheet parameter estimation, or surrogate modeling.

• Uncertainty propagation, or validation of models against operating plant data.

• Hands-on pilot or plant experience in mineral processing or a comparable industry.

Compensation

The base salary range for this role is $160,000 – $200,000 per year.

Compensation decisions are made based on track-record, seniority, and skill set. Additional consideration can be given to candidates with exceptional experience.

We’re proud to be an equal opportunity employer and consider qualified applicants without regard to race, color, religion, sex, national origin, ancestry, age, genetic information, sexual orientation, gender identity, marital or family status, veteran status, medical condition or disability.