Chemical Process Engineer Jobs in California (NOW HIRING)

Why Castelion, Why Now

Castelion is moving incredibly fast to develop and deliver advanced defense systems at a time when execution matters more than ever. We believe focus and technical excellence are decisive advantages - and we are building a team that can deliver real capability, not just concepts.

This is a rare opportunity to join at an early stage, where your work will directly shape critical systems, influence major technical decisions, and have immediate, real-world impact.

Staff Industrial Chemical Engineer – Wet Chemistry

Castelion is seeking an experienced Industrial Chemical Engineer to lead the scale-up of a wet chemistry processes from laboratory development to pilot and full-scale manufacturing. This role is critical to transitioning a proven laboratory reaction into a safe, reliable, and economically viable production process.

The engineer will be responsible for process design, equipment selection, scale-up strategy, process optimization, and operational readiness. This role requires significant experience with industrial chemical processing involving hazardous chemicals, reaction systems, fluid handling, and wet chemistry operations. The ideal candidate has successfully scaled chemical processes from bench or pilot scale into industrial production environments and is comfortable working in a fast-paced development setting.

Responsibilities

• Lead the scale-up of laboratory-developed chemical reaction processes into pilot and production-scale operations.
• Develop scale-up methodologies, process models, and engineering calculations to support commercialization efforts.
• Design, specify, and commission reactors, mixing systems, chemical delivery systems, and associated process equipment.
• Evaluate reaction kinetics, mass transfer, heat transfer, mixing, and fluid flow considerations during process scale-up.
• Conduct process hazard analyses (PHA), and risk assessments for hazardous chemical operations.
• Establish safe operating limits and process control strategies for industrial-scale chemical reactions.
• Lead troubleshooting and root-cause investigations related to process performance, yield, quality, and equipment reliability.
• Collaborate with chemists, technicians, operations personnel, and leadership to optimize manufacturing processes.
• Develop batch records, work instructions, standard operating procedures (SOPs), and manufacturing documentation.
• Support facility design, equipment installation, commissioning, and operational qualification activities.
• Ensure compliance with all environmental, health, and safety (EHS) requirements and applicable regulatory standards.

Basic Qualifications

• Bachelor’s degree in Chemical Engineering.
• 8+ years of experience in chemical manufacturing, process engineering, or industrial process scale-up.
• Demonstrated experience scaling chemical reaction processes from laboratory or pilot scale to commercial production.
• Strong background in industrial wet chemistry operations involving hazardous chemicals.
• Experience with chemical reactors, mixing systems, chemical handling equipment, pumps, piping systems, and process controls.
• Knowledge of process safety management (PSM), hazard analysis methodologies, and chemical process safety principles.
• Ability to work independently in a hands-on engineering environment and drive projects from concept through implementation.

Preferred Skills and Experience

• Master's degree in Chemical Engineering or related field.
• Experience with highly corrosive, toxic, reactive, oxidizing, or otherwise hazardous chemical systems.
• Experience commissioning and operating pilot plants or chemical production facilities.
• Familiarity with batch and continuous chemical manufacturing processes.
• Knowledge of industrial automation, PLC systems, and process control strategies.
• Experience supporting capital equipment procurement, facility design, and manufacturing scale-up programs.

Benefits And Perks

• Employee Equity: Meaningful equity for all full-time employees - share value has increased 150x in three years
• Personal Time Off: Four (4) weeks of paid time off to unplug, reset, and come back sharp—velocity matters, burnout doesn’t
• Company Paid Holidays: Ten (10) company paid holidays
• Medical: We offer plans at 100% employee covered and 80% of dependent coverage
• Dental & Vision: We cover 90% employees and 80% for dependents to ensure you and your family have access to quality preventive and ongoing care
• FSA/HSA: To support long-term health and financial resilience, we offer FSA and HSA options that allow employees to set aside pre-tax dollars for eligible medical and dependent care expenses
• Retirement: 401k plan offered to support long term financial growth along side high-impact, high-velocity work
• Paid Parental Leave: We support growing families with meaningful time to bond and recover. Birthing parents are eligible for up to 10 weeks of paid leave, while non-birthing parents may take up to 4 weeks of paid leave. This time can be used for pre-natal care, pregnancy, childbirth, and related medical needs—ensuring every parent has the support they need during this important life moment.8-weeks of paid parental leave for all parents. Additional paid pregnancy leave for CA employees
• Meals & Catering: Frequently catered lunches and team meals, plus company-covered meals when extra time or effort is required
• Snacks & Beverages: Fully stocked kitchen with unlimited snacks and drinks to keep you fueled throughout the day
• Performance & Fitness: $100 monthly fitness stipend to support peak performance and health, both inside and outside of work
• EV Charging: Onsite electric vehicle charging available for employees

Physical Demands

• Must be willing to work extended hours and/or weekends as needed
• Must be able to travel up to 30%
• Must be able to lift more than 50lbs

ITAR Requirements

To conform to U.S. Government export regulations, applicant must be a (i) U.S. citizen or national, (ii) U.S. lawful, permanent resident (aka green card holder), (iii) Refugee under 8 U.S.C. § 1157, or (iv) Asylee under 8 U.S.C. § 1158, or be eligible to obtain the required authorizations from the U.S. Department of State.

This position may require access to classified information or restricted U.S. Government sites, systems, or information, as determined by the Company and/or applicable U.S. Government requirements. If the position is so designated, your employment in the role may be contingent upon your ability to obtain and maintain the required U.S. Government security clearance or other government authorization, and to satisfy any citizenship or other eligibility requirements imposed by applicable law, regulation, executive order, or government contract requirements. You will be notified if and when such requirements apply. Failure to obtain or maintain any required clearance or authorization may result in reassignment, leave, or separation from employment, consistent with business needs and applicable law.

Affirmative Action/EEO Statement

Employment with Castelion is governed on the basis of competence and qualifications and will not be influenced in any manner by race, color, religion, gender, national origin/ethnicity, veteran status, disability status, age, sexual orientation, gender identity, marital status, mental or physical disability or any other legally protected status.

Other Duties

Please note this job description is not designed to cover or contain a comprehensive listing of activities, duties or responsibilities that are required of the employee for this job. Duties, responsibilities and activities may change at any time with or without notice.