• Partner with designers and engineers to build microsites for product releases. • Maintain webAI's marketing website, keeping it fresh, performant, and aligned with our evolving brand and product vision. • Champion user experience and accessibility across the front-end stack, maintaining a high quality bar.

• Build and maintain the components, patterns, and foundations (tokens, type, color, layout) that Mercury's product is woven from, holding a high bar for accessibility, performance, and pixel-level craft. • Lead projects that ship new UI patterns to solve real pain points for product teams, helping them build better experiences faster. • Develop a design system that's as ready for AI as it is for people, applying the technology to create leveraged outcomes. • Invest in the design system's prototyping experience, shaping the next iteration of how our design function rapidly prototypes, iterates on the product, and explores new concepts. • Raise the craft and AI fluency of the people around you, through mentorship and clear best practices.

Role Description The Principal Mechanical Engineer is accountable for the overall mechanical engineering strategy, technical governance, and lifecycle performance of utility-scale gas-fired power plants, including gas turbine– and gas reciprocating engine–based generation facilities. This role serves as the owner-side mechanical authority across the full project lifecycle—from early development and Pre-FEED through EPC execution, commissioning, and operations. The principal defines mechanical design philosophy with emphasis on heavy civil/structural, governs EPC and OEM designs, and ensures plant reliability, availability, and long-term operability, particularly for high-duty and mission-critical applications such as data center–driven power supply. This position requires a blend of high-level technical expertise with a general understanding of commercial aspects, regulatory awareness, and cross-functional coordination to bring utility scale power projects to life. The employee may be required to perform other job-related duties as requested by management. All duties will be assigned in accordance with applicable laws and company policies. Responsibilities - Mechanical Engineering Technical Authority (Owner-Side) - Establish and own the overall mechanical engineering philosophy for gas-fired power plants (SCGT, CCGT, and reciprocating gas engine). - Act as the final technical decision-maker for mechanical system design, equipment selection, and lifecycle-related issues. - Define company-wide standards for: - Rotating equipment and balance-of-plant (BOP) systems - Redundancy, sparing philosophy, and maintainability - Design margins, derating, and availability targets - Plant System Engineering Design (Owner-Side) - Lead plant-level system and process engineering for gas-fired power plant projects from concept through execution. - Develop and review key system design deliverables, including: - Fuel Gas System configuration and pressure/flow control philosophy - Heat & Material Balance diagrams - Water Balance Diagrams for various operating scenarios - Perform and validate cycle analysis for SCGT, CCGT, and gas engine plants, including: - Plant efficiency, heat rate, and auxiliary power assessment - Impact of ambient conditions, part-load operation, and degradation - Define overall plant configuration and operating concept based on system-level trade-off studies. - Ensure consistency between system design assumptions and detailed mechanical/BOP design. - Prime Mover & Major Equipment Oversight - Provide technical leadership for gas turbines and gas engines, including: - Performance, efficiency, and degradation assumptions - Operating envelopes and dispatch flexibility - Maintenance strategies and long-term service considerations - Govern selection and integration of: - Heat Recovery Steam Generators (HRSGs) - Steam turbines (where applicable) - Compressors, pumps, fans, and major auxiliaries - Balance of Plant (BOP) & Thermal Systems - Own mechanical scope for plant BOP systems, including: - Fuel gas systems - Cooling systems (air-cooled, water-cooled, hybrid) - Lube oil, seal oil, and auxiliary fluid systems - Compressed air and utility systems - Below ground and above ground piping - Ensure thermal and mechanical designs support: - High ambient operation - Frequent start-stop and load-following duty - Long-term reliability and maintainability - EPC, OEM & Owner’s Engineer Governance - Lead engagement with: - EPC contractors - OEMs (GT, engine, HRSG, major equipment suppliers) - Owner’s Engineers (OE) - Review, challenge, and approve key deliverables, including: - Mechanical & piping design criteria and specifications - Equipment datasheets and technical bids - P&IDs, layouts, and equipment arrangements - Stress, vibration, and fatigue-related analyses - Civil structures, foundations & earthwork - Ensure EPC and OEM designs align with owner objectives for reliability, operability, and lifecycle cost. - Project Development, Risk & Due Diligence - Provide mechanical engineering leadership during: - Pre-FEED and FEED decision gates - Project acquisitions and technical due diligence - Identify mechanical-system-related risks affecting: - Availability and forced outage rates - CAPEX and OPEX - Schedule, constructability, and commissioning - Support mitigation strategies and owner positions in commercial and technical negotiations. - Plant Performance, Availability & Lifecycle Optimization - Ensure mechanical systems support high availability targets (e.g., 99.9%+ where applicable). - Oversee evaluation of: - Mechanical bottlenecks and single points of failure - Maintenance intervals and outage strategies - Spare parts philosophy and long-lead items - Drive continuous improvement of plant design based on operating experience. - Technology Strategy & Future Readiness - Define long-term mechanical strategy to support: - Future SCGT → CCGT conversion - Carbon capture readiness (where applicable) - Evaluate emerging technologies and equipment from an owner’s perspective, balancing innovation with bankability. - Leadership & Cross-Functional Alignment - Provide technical direction and mentorship to senior and staff-level mechanical engineers. - Coordinate closely with: - Electrical and Controls engineering leadership - Development, commercial, environmental, regulatory and operations teams - Translate complex mechanical issues into clear, actionable recommendations for executive leadership. Qualifications - Bachelor’s degree in Mechanical Engineering, or Industrial Engineering. - 10+ years of experience in power plant mechanical engineering, EPC, OEM, or owner-side roles. - Proven experience with gas turbine and/or gas engine power plants. - Demonstrated experience acting as a discipline lead or technical authority is strongly preferred. - Deep expertise in: - Rotating equipment and thermal systems - Gas turbines, gas engines, and HRSGs - Balance-of-plant mechanical systems - Strong understanding of: - High-temperature, high-cycle duty operation - Mechanical reliability, fatigue, and vibration - Plant availability and lifecycle cost drivers - Familiarity with applicable standards (ASME, API, ISO, OEM standards). - Ability to set mechanical engineering direction and enforce standards across multiple projects. - Strong engineering judgement balancing reliability, cost, schedule, and risk. - Confident communicator with EPCs, OEMs, and executive stakeholders. - Comfortable operating in fast-moving project development environments. - Experience supporting data center power supply projects or other high-availability applications. - Exposure to engine-based generation or hybrid plant configurations. - Experience with heavy civil/structural & piping design and construction. - Experience with hydrogen-ready or low-carbon power technologies. - Professional Engineer (PE) license. Compensation - $180,000 - $200,000 salary

• Build, scale and evolve our design system: the component library, design tokens, and documentation that give product teams a consistent, accessible foundation to build on. • Extend our design system for AI-assisted development so AI coding tools and agents can use our components, tokens and guidelines as easily as people can, with Storybook as the backbone and machine-readable interfaces (e.g. MCP) layered on top. • Design component APIs that resist misuse, so AI and human developers alike can build with confidence. • Write high-quality, performant frontend code (React/TypeScript) and raise the bar for component craft and consistency across the engineering org. • Partner closely with design, product and engineering to define components together and take them all the way to something that holds up in production. • Make our components accessible by default, meeting WCAG 2.2 AA, and work closely with our Accessibility engineer to bake in best practices from the start. • Own the developer experience of the design system: clear documentation, guidelines, Storybook, sensible component APIs, versioning and smooth migration paths that make adoption easy for both human and AI consumers. • Implement and maintain theming, white labelling, and localization/RTL support so the system works for a global audience. • Continuously improve the system based on adoption metrics, contributor feedback and new platform capabilities. • Shape the technical direction of the design system over the next 6–12 months, championing its adoption across teams.