Senior Firmware Engineer - Communications

Lunar Energy; San Francisco (CA); On-site; USD 120,000 - 175,000; Full time

Benefits offered by this job

Medical Insurance

Dental Insurance

Vision Insurance

PTO & Holidays

401(k) Plan

Parental Leave

EV charging

Job summary

Lunar Energy seeks a Sr Firmware Engineer to own the firmware development lifecycle for home energy products. You will design, implement, test, and optimize firmware across power electronics, system behaviors, and interfaces, working with a cross-functional team to deliver reliable, scalable solutions.

Ideal candidates bring 5+ years of firmware experience, ESP-IDF know-how, and strong C/C++ skills, along with proficiency in network protocols and lab testing tools.

Qualifications

• Degree in computer engineering or related field.
• 5+ years delivering firmware for new products as part of a team.
• Experience with CAN and Protocol Buffers.
• Espressif ESP-IDF product development experience.
• Embedded Ethernet stacks and TCP/IP knowledge.

Responsibilities

• Design firmware for home energy product components including power electronics controls and system diagnostics.
• Collaborate with cross-functional teams to refine features and ensure reliability at scale.
• Develop tests, simulations, and validation plans to verify firmware behavior.
• Support manufacturing with automation features and partner integration.

Skills

Wireless mesh networking

C/C++ programming

Embedded software development

Cross-functional collaboration

Diagnostics & test skills

Education

Bachelor's in computer engineering or related field

Tools

ESP-IDF

TCP/IP / BSD Sockets

Oscilloscopes & Logic Analyzers

cmake

Python

Job description

Sr Firmware Engineer

Embedded/Firmware Engineers at Lunar will be responsible for the full product development lifecycle of our products' firmware and software, which are important sources of functionality, adaptability, and optimization of our designs. We are looking for people who are passionate about a more sustainable future, and want to make that vision a reality. An ideal candidate is excited and ready to collaborate closely with a dedicated, cross-functional team to deliver innovative, best-in-class products. Engineers at Lunar are hands‑on and involved in all aspects of the product, and own the design from forming concepts based on first principles to managing high‑volume production quality.

Lunar Energy was founded to transition homes to 100% clean energy—making our electricity greener, our air cleaner and our energy more safe, secure and reliable for all. We're a fast‑growing, global company building the world's best clean energy products to electrify all homes and connect communities to form clean, resilient virtual power plants.

On a given day at Lunar, you'll likely…

• Work collaboratively with other disciplines across the company to continuously refine and improve our understanding of how our products can create the greatest impact, get to market quickly, and operate reliably for our customers
• Help us create the best possible products by brainstorming and evaluating new features and solutions and weighing pros and cons to narrow down options.
• Test ideas and designs: back-of-the envelope calculations, building simulations and designing validation tests
• Design firmware software that runs in our home energy product components: Power electronics controls, system‑level behaviors and optimization, mobile app design and interfaces, system diagnostics and updates, RF and powerline communication protocols, control algorithms, and installation automation features.
• Optimize manufacturing by designing automation support functionality in our components whose design reflects the part they play in the processes that create them and test them, and by supporting our features within our manufacturing partners

Ideal Candidate Skills

Ideal candidates will have development experience with a wireless mesh network framework like esp‑wifi‑mesh, and will have been part of a development team which released high volume products where 24/7 communications reliability was a core requirement.

Desired Skills

• Degree in a computer-engineering related or adjacent field, or demonstrated commensurate ability.
• 5+ years experience delivering firmware for new products as part of a team.
• Experience with communication protocols, CAN, Protocol Buffers
• Espressif ESP-IDF product development experience
• Embedded Ethernet stacks, TCP/IP, BSD Socket API, HTTPS
• Wireless communication experience: WiFi, WiFi Mesh, Bluetooth/BLE, BLE-Mesh
• Proficiency in C, and working familiarity with cmake and Python
• Working knowledge of Oscilloscopes, Logic Analyzers and other lab test equipment

Benefits

We're dedicated to creating a remarkable employee experience. At Lunar, competitive base pay is one part of our total compensation package. Lunar employees also have the opportunity to become Lunar shareholders by getting equity in a fast-growing company and participating in our employee stock program.

Additional benefits include:

• Medical, dental, and vision insurance for employees and dependents
• Flexible Paid Time Off plus 10 paid holidays
• Tax deferred 401(k) plan
• Paid parental leave for all full time employees including 12 weeks paid parental leave for the birthing mother and 6 weeks paid parental leave for the non-birthing parent
• Subsidized EV charging and pre‑tax commuter benefits

Our DE&I Philosophy

Lunar Energy is an equal opportunity employer. We are committed to attracting, developing and retaining diverse talent by supporting an inclusive workplace. Lunar recruits, hires, trains, promotes, compensates, and administers all personnel actions without regard to race, religion, color, national origin, gender, sexual orientation, age, marital status, veteran status, disability status or any other status protected by applicable law.

Our Compensation Philosophy

Our goal is to ensure that all Lunar Energy employees are fairly compensated. Please note that the salary range information that follows is a good faith estimate for this position provided pursuant to the Pay Transparency for Pay Equity Act for California applicants. The salary range estimate for this position depending on level of experience is $120,000 - $175,000 USD

The actual offer, reflecting the total compensation package & benefits, will be at the company's sole discretion, and determined by factors including but not limited to years of experience, job level, geographic location, and other relevant business considerations. The company also reserves the right to amend or modify this job description, employee perks, and benefits at any time.