Extractive Metallurgist at Mariana Minerals | San Francisco

About Mariana MineralsMariana Minerals is a pioneering software-driven, vertically integrated minerals company dedicated to supplying the essential minerals that fuel modern energy, artificial intelligence, and defense technologies. We are transforming the minerals supply chain by leveraging extensive industry knowledge alongside cutting-edge software, automation, and data-centric decision-making.The RoleAs we build the critical minerals supply chain from the ground up, we seek a highly skilled Senior Machine Learning Engineer to help drive our autonomous operations.Unlike traditional software companies, we are a mining company that develops our own software solutions. Mariana designs, builds, commissions, and operates our own mines and refineries, where we create proprietary chemical processes. Currently, we are producing battery-grade lithium salts from real oil and gas wastewater at our facilities. Our first commercial-scale lithium production facility, Lithium One, is set to commence initial production in the first half of 2027.In your role as a Senior Machine Learning Engineer, you will spearhead the design and implementation of machine learning systems that directly optimize the operations of our mineral refining facilities and guide significant investment and operational decisions. Your contributions will be visible in tangible metrics such as recovery rates, energy consumption, reagent usage, and equipment uptime.The TechThis position involves some of the most compelling applied AI work available today.Our internal platform, PlantOS, utilizes the same reinforcement learning frameworks that power self-driving cars and humanoid robots, adapted for the autonomous and short-interval control of mineral refining circuits. Our models dynamically adjust operating parameters in real time, optimizing for lithium recovery, reagent consumption, energy efficiency, and equipment uptime simultaneously.The working environment is complex and ever-changing; variations in wastewater compositions, ore grades, and aging equipment require the system to adapt continuously. The ultimate objective is to achieve fully autonomous refining operations—when you implement your solutions here, you will witness the physics of the process evolve.What You’ll DoCollaborate closely with Mariana’s process chemistry and engineering teams to develop innovative, data-driven models of core chemical unit operations.Train and deploy reinforcement learning models to optimize operational processes.

About Mariana MineralsMariana Minerals is a pioneering minerals company that leverages software and automation to revolutionize how critical minerals are sourced, refined, and optimized. Our mission is to supply the essential materials that drive modern energy solutions, artificial intelligence, and defense technologies.By integrating deep industry expertise with cutting-edge technology and data-driven methodologies, we are setting new standards in responsible mineral sourcing. Join us in reshaping the future of mineral supply chains.Role OverviewWe are seeking a passionate and driven Mechanical Engineer to contribute to the development of our critical minerals supply chain, essential for supporting the global energy transition.In this role, you will spearhead the creation and implementation of innovative chemical refining processes, while also supporting software development for project execution and plant optimization. Your responsibilities will encompass designing, constructing, and commissioning pilot and modular commercial-scale plants, formulating first-principles models of refining equipment and processes, and managing equipment scopes from concept through to design, installation, commissioning, and handover to operations.What You’ll DoLead mechanical engineering projects across all phases—from concept and feasibility to detailed design, procurement, fabrication, installation, and commissioning.Develop comprehensive site-wide and area-level plant layouts that optimize equipment arrangement, maintenance access, constructability, safety, and multidisciplinary integration.Prepare mechanical equipment specifications, data sheets, and requisition packages for a wide range of process and solids-handling equipment, while assisting in technical evaluations and vendor selection.Design, assess, and integrate solids-handling and material-conveyance systems, including silos, bins, hoppers, feeders, conveyors, bucket elevators, chutes, and dust-control mechanisms.Assist in the development of 3D models and piping/mechanical interface layouts, ensuring compatibility with process, structural, civil, and electrical engineering requirements.Review vendor drawings and calculations to ensure compliance with mechanical design standards, project requirements, codes, and maintainability criteria.

About Mariana MineralsAt Mariana Minerals, we are pioneering a software-centric approach to mineral sourcing. Our mission is to deliver the critical minerals essential for modern energy, AI, and defense technologies. We aim to transform the mineral supply chain through innovative software, automation, and data-driven strategies.Join us in our quest to redefine responsible mineral sourcing and supply for a sustainable future.Role OverviewWe are in search of a dynamic and detail-oriented Project Engineer to help develop the critical minerals supply chain that supports the global transition to renewable energy. In this position, you will facilitate communication among engineering, procurement, construction, and operational teams to ensure project success.Your responsibilities will include maintaining project workflows, overseeing document control, tracking engineering and vendor deliverables, coordinating reviews across disciplines, managing RFIs, and creating dashboards for real-time project insights.

About Mariana Minerals Mariana Minerals is a software-focused minerals company based in San Francisco. The team delivers essential minerals that support energy, artificial intelligence, and defense technologies. By combining industry expertise with advanced software, automation, and data-driven methods, Mariana Minerals aims to transform the minerals supply chain. Mechanical Engineering Intern – Role Overview The Mechanical Engineering Intern will join the Pilot Plant Operations team at the San Francisco headquarters. This role centers on hands-on work: designing, improving, and optimizing benchtop pilot plant equipment. Interns collaborate with seasoned engineers and domain experts, gaining practical experience that goes well beyond typical support tasks. What You Will Do Create 3D models, layout drawings, and technical documentation for laboratory and pilot plant equipment. Build, test, and refine mechanical solutions to improve equipment performance, reduce downtime, control costs, and support health and safety. Work with engineering, management, and software teams to develop programs and applications that advance Mariana Minerals’ operations. Partner with colleagues from engineering, operations, and controls engineering to reach project objectives. Share your findings and experiences in a final presentation at the end of the internship. Desired Qualifications Currently enrolled in or recently graduated from a mechanical engineering or related degree program. Solid grasp of mechanical design documentation, including equipment specifications, layout drawings, piping diagrams, and CAD models. Hands-on experience designing or supporting industrial equipment such as pumps, piping systems, reactors, separators, filtration systems, or material handling equipment. Ability to design mechanical solutions independently, troubleshoot issues, and analyze complex data sets. Strong technical writing, communication, and teamwork skills. Comfortable adapting to changing priorities and managing multiple tasks in a busy environment. Why Mariana Minerals? Interns at Mariana Minerals join a mission-driven group focused on reshaping the future of critical minerals supply.

About Mariana Minerals Mariana Minerals is a software-driven minerals company based in San Francisco. The team supplies essential minerals for the energy, artificial intelligence, and defense industries. By combining deep industry knowledge with advanced software, automation, and data strategies, Mariana Minerals is rethinking how minerals reach the world’s most critical sectors. Internship Overview The Process Engineering Intern will join the Pilot Plant Operations team at Mariana Minerals’ San Francisco headquarters. This internship offers the chance to work on meaningful, hands-on projects in mineral processing. Interns conduct benchtop experiments, support pilot plant test runs, and help develop new operational programs. Close collaboration with experienced engineers and subject matter experts is a core part of the experience. This role focuses on building and delivering new solutions, not just supporting existing work. What You Will Do Run experiments in both lab and pilot plant settings to help reduce risks in scaling up minerals processing. Develop, test, and refine approaches to improve product recovery, minimize equipment downtime, control costs, and support health and safety. Work with engineering, management, and software teams to create programs and tools that advance operational goals. Collaborate with cross-functional groups, including operations and analytical labs. Present findings and insights at the end of the internship. What We’re Looking For Current student or recent graduate in chemical engineering, metallurgy, materials science, or a related field. Strong grasp of process design, thermodynamics, and reaction engineering. Hands-on experience in laboratory, pilot plant, or commercial plant settings through coursework, projects, or previous internships. Skilled in experimental design, troubleshooting, and independent analysis of complex data. Clear technical writing, communication, and collaboration abilities. Comfortable adapting to new challenges and working in a changing environment. Why Mariana Minerals? Interns at Mariana Minerals join a mission-driven team working to transform the global sourcing and supply of critical minerals. Every contribution supports a larger vision for the future of the industry.

About Mariana Minerals Mariana Minerals is a software-driven minerals company based in San Francisco. The team supplies essential minerals that support energy, artificial intelligence, and defense technologies. By combining deep industry experience with automation, software, and data-driven decision-making, Mariana Minerals aims to modernize the minerals supply chain. Internship Overview The Project Engineering Intern will join the Special Operations team to work on projects that directly impact mine operations. This role centers on building and deploying solutions, not just supporting ongoing work. Interns will collaborate closely with engineers and industry experts, contributing to the development of the MineOS product and exploring new technologies. What You Will Do Take ownership of a major operations project, guiding it from problem identification to execution and delivery. Build internal tools, dashboards, or lightweight applications to improve operational processes. Analyze operational data to spot inefficiencies and suggest improvements. Use AI tools such as Replit and Claude for rapid prototyping and solution deployment. Work closely with engineering and operations teams to turn practical challenges into working systems. Iterate on solutions quickly, applying feedback and deploying in real or near-real environments. Share progress, insights, and recommendations during weekly program review meetings. Location This internship is based at Mariana Minerals' San Francisco headquarters.

About Mariana MineralsAt Mariana Minerals, we are a pioneering minerals company that prioritizes software innovation. Our mission is to provide essential minerals that power the modern energy sector, artificial intelligence, and defense technologies. We are transforming the minerals supply chain by leveraging deep industry knowledge alongside cutting-edge software, automation, and data-driven decision-making.Join us in our commitment to responsible mineral sourcing and supply as we shape the future.Role OverviewWe are seeking a talented Senior Full Stack Software Engineer to lead significant technical projects aimed at developing the next-generation critical minerals supply chain, supporting the global transition to sustainable energy.In this role, you will be responsible for architecting, leading, and delivering software systems that enhance the engineering and construction of vital infrastructure for our minerals supply chain. You will set the technical direction, mentor team members, and oversee the complete delivery of intricate systems. Your key responsibilities will include designing and implementing robust integrations with existing engineering and construction software tools, creating scalable solutions to address internal team challenges, collaborating with ML engineers to implement large language models for unstructured data issues, and leading the creation of a new 'operating system' for the engineering and operation of our mineral processing facilities.This full-stack position requires proficiency in writing production-quality frontend code along with a strong understanding of system design and backend architecture. You will navigate seamlessly between user interfaces and distributed systems, ensuring quality at every layer of the software stack.

Join our dynamic team at Mariana Minerals as a Lab Technician, where you will play a crucial role in supporting our innovative mineral exploration and analysis projects. In this hands-on position, you will be responsible for conducting laboratory tests, preparing samples, and ensuring the accuracy and reliability of data. If you are passionate about science and eager to contribute to exciting discoveries, we want to hear from you!

About Mariana MineralsAt Mariana Minerals, we are a pioneering, software-driven minerals company dedicated to supplying the essential minerals that are critical for modern energy, AI, and defense technologies. Our innovative approach redefines how minerals are sourced, refined, and optimized through a blend of deep industrial knowledge and cutting-edge software, automation, and data-driven decision-making. Join us in revolutionizing responsible mineral sourcing and supply.Role OverviewWe are seeking a proactive Hydrometallurgical Process Engineer to contribute to the development of the critical minerals supply chain essential for the global energy transition.As a Hydrometallurgical Process Engineer with Mariana Minerals, you will spearhead the creation and implementation of innovative chemical refining processes. Your role will also involve supporting the development of software for capital project execution and enhancing automated plant optimization. You will be responsible for overseeing equipment scopes from initial concept to design, installation, commissioning, ramp-up, and handover to the operations team.What You Will DoLead hydrometallurgical process equipment scopes from concept development and modeling validation through procurement, detailed engineering, fabrication, installation, commissioning, and ramp-up.Manage relationships with external technology licensors, equipment vendors, and engineering partners to deliver fully integrated and efficient hydrometallurgical refining systems.Develop comprehensive heat and material balances for complex hydrometallurgical process trains, including leaching, solution purification, solvent extraction/ion exchange, precipitation, crystallization, and residue handling.Create hydraulic models and process flow diagrams/P&IDs for hydrometallurgical circuits, ensuring operational efficiency, reliability, and safety.Develop first-principles models of chemical reactors and unit operations (e.g., leach reactors, autoclaves, SX settlers, IX columns, precipitation reactors, filtration systems) to validate scale-up and mitigate risks in commercial designs.Identify, assess, and implement engineering solutions to enhance extraction, purification, and recovery processes under varying chemistries, feedstock qualities, and operating conditions.

Join Mariana Minerals as a Mechanical Maintenance Technician, where you will play a crucial role in ensuring the smooth operation of our machinery and equipment. As part of our dedicated team, you will be responsible for performing routine maintenance, troubleshooting mechanical issues, and implementing effective solutions to enhance operational efficiency.

Join Mariana MineralsAt Mariana Minerals, we are revolutionizing the minerals supply chain. As a software-first, vertically integrated minerals company, our mission is to provide the essential minerals that power modern energy, artificial intelligence, and defense technologies. We harness deep industry knowledge combined with cutting-edge software, automation, and data-driven insights to redefine the way minerals are sourced and processed.Your Role as Staff Product ManagerWe are seeking a dynamic Staff Product Manager to lead a crucial area within MarianaOS. This position is unique as we prioritize recruiting top-tier product managers first and then align them to the most suitable segment of our operations based on their strengths and experiences. Together during the interview process, we will identify the ideal fit for your skills.The potential impact of this position is vast. The mining industry is one of the last major sectors yet to be transformed by modern software technologies. Your work will not merely close feature gaps but will create entirely new workflows and systems. The challenges range from micron-scale chemistry all the way to kilometer-scale infrastructure.By delivering features, you will directly influence metrics such as recovery rates, reagent consumption, construction timelines, and equipment uptime. These are not merely abstract metrics; they reflect the tangible physics of metal production. This role requires on-site engagement and will involve significant travel.About MarianaOSMarianaOS serves as the digital backbone for our mineral projects, overseeing the entire lifecycle from capital project execution to autonomous operations. We are currently focusing on three key domains:MineOS: This platform integrates geological block models, mine planning, fleet management systems, and industrial control systems into a cohesive optimization layer, enhancing autonomous fleet deployment and developing an accurate digital twin of mining sites.PlantOS: Our autonomy platform for fixed-plant mineral processing, including lithium refining and flotation, which employs a reinforcement learning toolkit similar to those used in self-driving technologies for autonomously controlling mineral refining circuits.BizOS: The operational system that streamlines business processes by connecting disparate tools, removing manual handoffs, and providing leadership with real-time insights into project economics and operational performance across the organization.

About Mariana MineralsMariana Minerals is a software-driven, vertically integrated minerals company dedicated to providing the essential minerals that power modern energy solutions, artificial intelligence, and defense technologies. We are transforming the minerals supply chain by leveraging extensive industry expertise alongside cutting-edge software, automation, and data-informed decision-making.The RoleWe are seeking a Senior Technical Recruiter (Contract) to spearhead full-cycle recruitment for pivotal technical and business positions during a crucial growth period at Mariana Minerals. This is a contract role lasting 6-12 months, where your mission will be to devise and implement effective recruiting strategies aimed at attracting, evaluating, and securing top talent in competitive markets.You will collaborate closely with hiring managers and leadership teams, overseeing the recruitment process from start to finish, employing deep market insights, and continuously optimizing recruitment practices through data analysis, systems enhancement, and automation.What You’ll DoManage the entire recruitment process for both technical and non-technical roles, from initial intake to final offer acceptance.Translate complex job specifications into tailored, high-quality sourcing strategies.Develop robust talent pipelines through innovative sourcing methods beyond conventional channels.Work in partnership with hiring managers to ensure alignment, priority setting, and rapid decision-making.Provide candidates with a top-tier, engaging experience marked by clear communication and minimal drop-off rates.Monitor and analyze recruitment funnel metrics (pipeline health, conversion rates, time-to-fill) utilizing Ashby.Proactively identify and address potential hiring obstacles, presenting strategic solutions.Effectively communicate Mariana’s mission, culture, and unique value proposition to attract and secure top candidates.Contribute to the enhancement of recruitment processes, interview methodologies, and overall hiring philosophy.

About Taskrabbit:Taskrabbit is an innovative marketplace platform that seamlessly connects individuals with Taskers to manage everyday home tasks, including furniture assembly, handyman services, moving assistance, and much more.At Taskrabbit, we aim to transform lives one task at a time. We celebrate innovation, inclusion, and hard work, fostering a collaborative, pragmatic, and fast-paced culture. We seek talented, entrepreneurially minded, data-driven individuals who possess a passion for empowering others to pursue their passions. In partnership with IKEA, we are creating more opportunities for individuals to earn a consistent, meaningful income on their terms by establishing enduring relationships with clients in communities globally.Taskrabbit operates as a hybrid company, with team members located across the US and EU, and has been recognized as a Built In — Best Places to Work for 2022, 2023, and 2024, receiving accolades across various national and regional categories. Join us at Taskrabbit, where your contributions will be significant, your ideas appreciated, and your potential maximized!This position operates on a hybrid schedule, requiring two days of in-office collaboration per week. It can be based in our San Francisco office or our new New York City office (opening March 2026).About the RoleMachine Learning is a foundational element at Taskrabbit, and we are in search of an experienced Senior Machine Learning Engineer to join our team and help mold the future of ML/AI at Taskrabbit. This distinct, full-stack role is designed for someone who is enthusiastic about the entire machine learning lifecycle—from initial research and model development to constructing the robust infrastructure necessary for deploying and scaling your innovations.As a Senior Machine Learning Engineer, you will engage with exciting challenges that directly influence how users discover and interact with home services on the Taskrabbit platform. You will play a vital role in enhancing our capabilities in areas such as search ranking, content discovery, and recommendation systems. Collaborating closely with data scientists and fellow engineers, you will design and implement cutting-edge algorithms, ensuring the scalability, reliability, and optimization of our models in production alongside software engineers.

About VSCO At VSCO, we empower photographers with an innovative platform that provides essential tools, a vibrant community, and the visibility needed for creative and professional growth. We cultivate an authentic creative environment that welcomes photographers of all skill levels, offering a space that inspires opportunity, collaboration, and connection. Our mission is to support photographers in their journeys, enabling them to thrive and connect with fellow creatives and businesses through our comprehensive suite of tools, available on both mobile and desktop. We seek individuals who are passionate and proactive in advancing our mission. Our team members have the opportunity to make a significant impact, and we believe that collaborative efforts yield stronger results. Our core values are essential to our team culture and guide our hiring process. Learn more about what you can expect when joining VSCO on our Careers Page. About The Role As a Senior Machine Learning Engineer, you will harness the power of AI and machine learning to create innovative, reliable user-facing product features. You will leverage your extensive technical background and hands-on experience in deploying machine learning models to deliver impactful solutions based on real-world feedback. Your focus on measurable outcomes and customer satisfaction drives your work, blending innovation with practical implementation. You will be highly skilled in Python and adept across the data and machine learning stack, enabling you to develop and launch models efficiently while ensuring scalability and maintainability. Whether working with traditional algorithms or cutting-edge deep learning and generative AI, you will expertly navigate the complexity of each problem, managing every phase from defining the challenge to deployment and iterative improvement. Your dedication to software engineering excellence will inform your thoughtful approach to system design for machine learning, encompassing data quality, pipeline design, feature workflows, model serving, and ongoing monitoring and enhancement. By integrating machine learning deeply within our cohesive product experiences, you will collaborate effectively with cross-functional teams, aligning on objectives, defining success metrics, and driving meaningful outcomes. You will stay informed about the rapidly evolving AI landscape, maintaining a discerning perspective that allows your team to focus on significant advancements while avoiding distractions. The Day to Day Design and implement ML-powered features for search, discovery, personalization, and more.

Job OverviewJoin Eragon as a Machine Learning Engineer and lead the charge in transforming innovative AI models into scalable, production-grade systems. This position is pivotal in bridging research and real-world applications by designing and optimizing systems that enhance vital workflows throughout the enterprise.In collaboration with our research, product, and engineering teams, you will convert cutting-edge capabilities into dependable, high-performance systems ready for production.Key ResponsibilitiesModel Development & Deployment: Craft, refine, and deploy machine learning models within production settings.Systems Engineering: Architect scalable pipelines for training, inference, evaluation, and comprehensive monitoring.Performance Optimization: Enhance the latency, throughput, cost-efficiency, and reliability of ML systems.Data & Infrastructure: Manipulate large datasets and ensure seamless integration of models with internal systems and APIs.Cross-Functional Collaboration: Collaborate with product and engineering teams to provide end-to-end AI functionalities.Evaluation & Monitoring: Develop robust evaluation frameworks and feedback loops to ensure system effectiveness.

Join Our Mission to Empower Communities! At GoFundMe, we are the leading global platform dedicated to helping people support each other. Since our inception in 2010, we've facilitated over $40 billion in fundraising, uniting individuals and nonprofits in a safe and engaging environment. We are seeking a passionate and experienced Senior Manager, Machine Learning Engineering to join our Applied Science team. In this pivotal role, you will spearhead a dynamic team tasked with creating impactful machine learning solutions that enhance user experiences and drive business growth. Your responsibilities will include designing, developing, and deploying cutting-edge services and applications utilizing advanced machine learning and AI methodologies, such as generative AI, personalized recommendations, search systems, and classification techniques. This position requires exemplary leadership capabilities to ensure both strategic vision and tactical execution, backed by your extensive knowledge of machine learning, AI, and secure software practices. This role is based in the vibrant San Francisco Bay Area, with an expectation of being in the office three times a week.

At Sciforium, we are pioneering the future of AI infrastructure by creating cutting-edge multimodal AI models and a proprietary, high-efficiency serving platform. With substantial financial backing and direct support from AMD engineers, our team is rapidly expanding as we develop the comprehensive stack that drives advanced AI models and real-time applications.About the RoleIn the capacity of a Machine Learning Engineer, you will engage with the entire foundation-model stack, encompassing pretraining and scaling, post-training and Reinforcement Learning, sandbox environments for evaluation and agentic learning, and deployment + inference optimization. You’ll have the opportunity to rapidly iterate on research ideas, contribute to production-grade infrastructure, and help deliver models capable of addressing real-world challenges at scale.Your ResponsibilitiesThis position offers diverse tracks - candidates can specialize or contribute across multiple areas. Key responsibilities include:Pretraining & ScalingTrain expansive byte-native foundation models utilizing vast, heterogeneous data sources.Formulate stable training methodologies and scaling laws tailored for innovative architectures.Enhance throughput, memory efficiency, and resource utilization across extensive GPU clusters.Establish and maintain distributed training infrastructures alongside fault-tolerant pipelines.Post-training & Reinforcement LearningBuild out post-training frameworks (SFT, preference optimization, RLHF/RLAIF, RL).Curate and produce specialized datasets aimed at enhancing specific model capabilities.Develop reward models and evaluation systems to facilitate ongoing improvements.Investigate inference-time learning and computational strategies to boost performance.Sandbox Environments & EvaluationCreate scalable sandbox environments for agent assessment and learning.Generate realistic, high-signal automated evaluations for reasoning, tool usage, and safety.Design both offline and online environments that support RL-style training at scale.Implement instrumentation for observability, reproducibility, and rapid iteration.Deployment & Inference OptimizationOptimize deployment strategies to ensure models are efficient and effective in real-world applications.

Join Strava, a leader in the sports technology sector, as a Machine Learning Engineer. In this exciting role, you will apply your expertise in machine learning and data science to develop innovative solutions that enhance the experience of millions of athletes worldwide. Collaborate with cross-functional teams to create algorithms that analyze vast datasets and provide actionable insights to our users.

At Lyft, we are driven by our mission to connect and serve our communities. We strive to foster a workplace where every team member feels valued and has the opportunity to excel. With over half a billion rides and counting, Lyft is tackling complex challenges on a grand scale, utilizing cutting-edge AI and Machine Learning technologies to enhance customer experiences. The Artificial Intelligence, Machine Learning, and Operations Research Platforms team (AIMLOR) is on the lookout for a Senior Machine Learning Engineer who will play a pivotal role in constructing AI Platform components that empower essential AI applications across Lyft. Mastery in Generative AI and platform development is crucial for this position. You will contribute to our platform that facilitates real-time, online, and offline AI and ML model execution, development, and iteration. Collaborating with a team of talented Machine Learning and Software Engineers, you will work on intricate problems and define solutions that make a direct impact on our systems throughout the organization. If you are enthusiastic about building an AI Platform at scale with applications spanning every aspect of our company, we want to hear from you. If you are a creative thinker with a strong background in AI and machine learning systems and are passionate about leveraging data to solve business challenges in a dynamic, innovative, and collaborative environment, we invite you to apply.