What are the responsibilities and job description for the Mechanical Engineer position at 3Si Security Systems?
At 3Si, our mission is to make your world, safer. As a global leader in innovative security technology, we help businesses and law enforcement prevent and respond to crime through field-proven solutions and trusted partnerships. With over 100 years of combined experience through our merged companies, our expertise drives measurable impact in communities worldwide.
We specialize in GPS tracking, video surveillance, and integrated response technologies that deter theft and accelerate criminal apprehension. Designed for retail, financial institutions, law enforcement, and more, our solutions combine cutting-edge tools with unmatched response capabilities. Through our exclusive DirectToDispatch™ technology, verified crime alerts are sent directly to law enforcement dispatch centers in real time—bypassing traditional third-party monitoring delays—to enable rapid, precise response when it matters most.
At 3Si, meaningful work makes a difference. We’re a purpose-driven team that values innovation, trust, and collaboration. From engineering to sales and support, every role contributes to our mission to protect communities and make the world safer. We offer a hybrid, flexible work culture, competitive benefits, and the chance to grow alongside a team of passionate, dedicated professionals.
Join us—and be part of something that matters. We are seeking a skilled and detail-oriented Mechanical Engineer to join our innovative engineering team at either our
Jefferson City, MO or Lawrenceville, GA
location. This role is responsible for the design and development of production-ready components and assemblies, with a strong emphasis on injection molding processes. The ideal candidate will have hands-on experience designing parts for high-volume manufacturing, including knowledge of DFM (Design for Manufacturability), tooling constraints, and material selection.
This position plays a critical role in taking products from concept through production, ensuring designs are optimized for cost, quality, and manufacturability. You will collaborate closely with cross-functional teams including electrical engineers, project managers, manufacturing personnel, and tooling vendors to ensure seamless integration and execution of designs.
Primary Responsibilities
Design and develop components and assemblies, ensuring compliance with industry standards and project specifications.
Collaborate with cross-functional teams, including manufacturing, quality, and sales, to integrate design concepts and functional requirements.
Utilize SolidWorks for design creation and modification, ensuring accuracy and adherence to project timelines.
Prepare detailed technical drawings and specifications for manufacturing and assembly.
Conduct testing and analysis of mechanical systems, interpreting results to optimize design.
Participate in design reviews and provide technical support throughout the product lifecycle.
Stay current with industry trends, materials, and emerging technologies in mechanical engineering.
Knowledge, Skills, And Abilities
Strong understanding of injection molding and/or die casting processes, materials, and tooling.
Ability to manage multiple projects simultaneously, meeting tight deadlines.
Strong communication and teamwork skills, with the ability to collaborate effectively in a team environment.
Knowledge of industry standards and mechanical engineering best practices.
Qualifications
Bachelor’s degree in Mechanical Engineering or a related field required.
3 years of experience in product design, with emphasis on injection molding processes.
Strong proficiency in CAD software (e.g., SolidWorks).
Additional Comments
Position will be based in Jefferson City, MO or Lawrenceville, GA location.
Less than 5% of travel.
Comprehensive benefits package including medical, dental, vision, life insurance, short- and long-term disability starting on your first day
401(k) retirement savings plan with company match