Senior Hardware Security Engineer

Lime is the largest global shared 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 States 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…