Application Guide

How to Apply for Senior Hardware Security Engineer

at Lime

🏢 About Lime

Lime is a leader in micromobility, operating shared electric scooters and bikes in over 200 cities worldwide. As a remote-first company committed to sustainable urban transportation, Lime offers a unique opportunity to work on cutting-edge hardware security challenges that directly impact the safety and reliability of millions of rides.

About This Role

As a Senior Hardware Security Engineer, you will lead security assessments of Lime's IoT devices, including scooters and charging infrastructure. Your work will involve threat modeling, physical attack testing, and firmware hardening to protect against real-world attacks, directly contributing to the trustworthiness of Lime's fleet.

💡 A Day in the Life

A typical day might start with a stand-up with the product security team, followed by setting up a fault injection experiment on a scooter's microcontroller. After lunch, you might review a threat model for a new charger design, then spend the afternoon developing a Python script to automate side-channel analysis. The day could end with mentoring a junior engineer on secure boot implementation.

🎯 Who Lime Is Looking For

  • Has 5+ years of hands-on hardware security experience, including side-channel analysis and fault injection on embedded devices.
  • Deep understanding of firmware security concepts like secure boot, TEEs, and hardware root of trust, with practical implementation experience.
  • Proficient with lab equipment (oscilloscopes, logic analyzers, fault injection tools) and can set up automated testing rigs.
  • Comfortable working in a remote, fast-paced startup environment and mentoring junior engineers.

📝 Tips for Applying to Lime

1

Tailor your resume to highlight specific hardware security projects, especially those involving IoT or embedded systems.

2

Include a portfolio or github link with examples of security tools or scripts you've developed for hardware analysis.

3

In your cover letter, mention any experience with side-channel or fault injection attacks on real devices, not just theoretical knowledge.

4

Research Lime's current fleet (e.g., Gen4 scooter) and mention any security concerns you'd address.

5

Prepare to discuss how you've handled incident response in a hardware context, as this is listed in the job description.

✉️ What to Emphasize in Your Cover Letter

['Emphasize your hands-on experience with physical attack assessment and firmware reverse engineering.', 'Show how your work has directly improved product security in a previous role, with measurable outcomes.', 'Express enthusiasm for micromobility and the unique security challenges of IoT devices in public spaces.', 'Mention your ability to work autonomously and collaborate remotely, as the role is remote-first.']

Generate Cover Letter →

🔍 Research Before Applying

To stand out, make sure you've researched:

  • Read about Lime's security blog or any public security disclosures they've made.
  • Understand the typical architecture of a Lime scooter (e.g., MCU, BMS, GPS, cellular modem).
  • Look into Lime's remote work culture and how product security teams collaborate across time zones.
  • Review recent academic papers or industry talks on IoT security for shared mobility devices.

💬 Prepare for These Interview Topics

Based on this role, you may be asked about:

1 Describe a time you performed a side-channel attack; what tools did you use and what was the outcome?
2 How would you secure a firmware update mechanism for a fleet of scooters?
3 Walk through your threat modeling process for a new IoT device.
4 How do you stay current with hardware security vulnerabilities and standards?
5 What lab equipment do you have experience with, and how would you set up an automated fault injection test?
Practice Interview Questions →

⚠️ Common Mistakes to Avoid

  • Don't focus solely on software security; this role is hardware-centric and requires lab skills.
  • Avoid generic statements like 'I'm passionate about security' without concrete examples.
  • Don't neglect to mention remote work experience; Lime is remote-first and values self-starters.

📅 Application Timeline

This position is open until filled. However, we recommend applying as soon as possible as roles at mission-driven organizations tend to fill quickly.

Typical hiring timeline:

1

Application Review

1-2 weeks

2

Initial Screening

Phone call or written assessment

3

Interviews

1-2 rounds, usually virtual

Offer

Congratulations!

Ready to Apply?

Good luck with your application to Lime!