Lime
Lime is the largest global micromobility business, operating in close to 30 countries across five continents. We’re on a mission to build a future where transportation is shared, affordable and carbon-free. Our electric bikes and scooters have powered more than one billion rides in cities around the world. Named a 2025 Time 100 Most Influential Company, Lime continues to set the pace for shared micromobility globally, spurring a new generation of clean alternatives to car ownership.
Lime is seeking an experienced Senior Hardware Security Engineer to join our Product Security team. In this role, you'll be a foundational member of our hardware security efforts, directly contributing to the confidentiality, integrity, and availability of Lime's hardware and firmware platforms. You will report to the Director of Security and play a key role in building out our hardware security program across our micromobility product portfolio.
We're a fast-paced, lean, and remote-first company, so we're looking for someone who thrives in an evolving environment, is a proactive problem-solver, and is passionate about building scalable and robust security solutions for embedded systems and physical products. This role is a fantastic opportunity for someone who wants to make a significant impact and help shape the future of hardware security at Lime.
This is a remote position with a requirement for candidates to reside in the United Kingdom to maintain effective collaboration across teams.
This position requires occasional travel to support business operations, which is considered an essential function of the role. Lime will provide reasonable accommodations as needed.
Security Architecture & Design: Contribute to hardware security architecture reviews for product platforms, providing security input on secure boot chains, hardware roots of trust, trusted execution environments (TEEs), and cryptographic implementations. Evaluate silicon and SoC security properties through vendor assessment, datasheet review, black-box testing, and security characterization of off-the-shelf and custom components. Research and evaluate emerging hardware security technologies (e.g., confidential computing, post-quantum cryptographic hardware, hardware-backed attestation) and provide recommendations to the team.
Threat Modeling & Risk Assessment: Conduct threat modeling exercises for hardware and firmware components, identifying attack surfaces across the product stack. Perform security risk assessments for new and existing hardware designs, quantifying risk and recommending mitigations with clear priority and business context. Communicate hardware security tradeoffs clearly to engineering peers and product stakeholders.
Security Assessment & Testing: Perform hands-on security assessments of hardware platforms, including side-channel analysis, fault injection testing, firmware reverse engineering, and debug interface evaluation. Contribute to building and maintaining a hardware security testing methodology and lab environment, including tooling for automated and repeatable assessments. Participate in vulnerability management for hardware and firmware components, including coordinating disclosure, remediation tracking, and validation of fixes.
Firmware & Platform Security: Develop firmware hardening recommendations and work with firmware engineering teams to implement secure boot, firmware update integrity, tamper detection and runtime protection mechanisms across product platforms. Contribute to security standards for embedded systems, microcontrollers, and platform firmware across the product portfolio. Work with platform teams to review hardware-software interfaces (e.g., UEFI, BMC, TPM interactions) for security concerns.
Incident Response & Forensics: Participate in incident response efforts for hardware and firmware security incidents, contributing to investigation, root-cause analysis, and corrective action to prevent recurrence.
Tooling & Automation: Develop and maintain automated security tooling for hardware and firmware analysis, vulnerability scanning, and compliance validation. Contribute to defining security gates within CI/CD and build pipelines for firmware, working with DevOps and firmware teams to support automated enforcement before production release.
Standards, Policy & Compliance: Contribute to hardware security standards, policies, and procedures that align with industry frameworks (e.g., NIST SP 800-193, Common Criteria, FIPS 140, IEC 62443). Support product security certifications and compliance efforts where hardware security attestation is required. Stay current with the evolving hardware threat landscape, supply chain security concerns, and regulatory requirements.
Collaboration & Mentorship: Serve as a subject matter expert on hardware security within the product security team, providing technical guidance to engineering peers. Share knowledge and help develop junior team members' hardware security skills through assessment reviews and design reviews. Help drive adoption of hardware security best practices within your project scope through clear documentation and hands-on support.
Stay Ahead of Threats: Continuously research and evaluate emerging hardware security threats, technologies, and best practices to recommend new approaches and solutions.
Travel: This role requires up to 10% of travel within EMEA and North America.
Experience: 5+ years of experience in a dedicated hardware or firmware security engineering role, with a strong focus on embedded systems, platform security, or product security.
Technical Depth: Demonstrated expertise across hardware security domains, with strong proficiency in at least one or two specialized sub-disciplines:
Firmware security: Secure boot, trusted execution environments (TEEs), firmware integrity, secure update mechanisms
Platform security: Hardware root of trust, TPM/secure enclaves, cryptographic implementations, SoC security properties
Physical attack assessment: Fault injection, side-channel analysis, hardware reverse engineering, debug interface security
Embedded systems security: Microcontroller hardening, RTOS security, hardware-software interface security
Working familiarity across other hardware security domains and eagerness to grow breadth over time
Hands-On Skills: Practical experience with hardware security testing methodologies, tools, and lab equipment. Ability to perform black-box security characterization, vulnerability assessment, and security validation of hardware components and firmware.
Problem-Solver: Excellent analytical and problem-solving skills with a proven ability to troubleshoot complex hardware security issues and propose effective, practical solutions that balance security with product requirements.
Communication: Strong written and verbal communication skills, with the ability to articulate complex technical hardware security concepts to both technical and non-technical audiences, including engineering peers and product stakeholders.
Team Player: Ability to work independently and as part of a lean, highly collaborative team, comfortable with remote work environments and cross-functional collaboration with firmware, hardware, and platform engineering teams.
Startup Mindset: Experience or comfort working in a dynamic, fast-paced startup or high-growth environment where you'll need to build processes and programs from the ground up.
Continuous Learner: Passion for hardware security and a commitment to staying current with the latest hardware security trends, attack techniques, and defensive technologies.
Education & Certifications: Bachelor's degree in Computer Engineering, Electrical Engineering, Computer Science, Cybersecurity, or a related field is preferred but not required. Relevant industry certifications such as GIAC Reverse Engineering Malware (GREM), Offensive Security Certified Professional (OSCP), or hardware-focused security certifications are a plus.
