Firmware Engineer

  • San Francisco, CA, USA
  • Employees can work remotely
  • Full-time
  • Alternate Location: San Francisco, United States

Company Description

Since we first opened our doors in 2009, the world of commerce has evolved immensely – and so has Square. After enabling anyone to take a payment and never miss a sale, we saw sellers stymied by disparate, outmoded products and tools that wouldn’t work together. So we expanded into software and started building integrated, omnichannel solutions – to help sellers sell online, manage inventory, run a busy kitchen, book appointments, engage loyal buyers, and hire and pay staff. And across it all, we’ve embedded financial services tools at the point of sale, so merchants can access a business loan and manage their cash flow all in one place.

Today, we’re a partner to sellers of all sizes – large, enterprise-scale businesses with complex commerce operations, sellers just starting out, as well as merchants who began selling with Square and have grown larger over time. As our sellers scale, so do our solutions. We all grow together.

There is a massive opportunity in front of us. We’re building a business that is big, meaningful, and lasting. And we are helping sellers around the world do the same.

Job Description

Our hardware team builds the tangible connection to all that is Block. As we introduce more and more of our products to the world, our hardware footprint expands. In this role, you will be responsible for developing software that simulates Block's hardware products, in order to expand our automated testing capacity and make the lives of our firmware developers easier by giving them the ability to test firmware code without using hardware devices. Ideally you will have firmware development experience, but have interest and/or experience developing host-side systems that run on the cloud.

You Will:

  • Build scalable simulators for all of Block's hardware products
  • Understand our payments processor at the lowest level, helping to build a virtualized version
  • Understand code written within the constraints of tiny embedded systems and modify it as necessary to work on Linux and Mac
  • Write integration code with CI/CD systems and cloud infrastructure services
  • Write and collaborate on new system-side code; including protocol design
  • Develop tests to validate product features, drivers, and system functionality
  • Collaborate with firmware, iOS and Android developers that will be using the simulators you build


  • 5+ years of relevant industry experience
  • A software development discipline, including modularization, documentation, and test methods
  • Firmware / Embedded software development experience
  • Expertise in C software development, tools, and debugging
  • Experience integrating with CI/CD and cloud infrastructure services (e.g. AWS, GCP)
  • Understanding of common communications protocols (e.g. SPI, UART, I2C, USB)
  • BS in CS, CE, EE, or equivalent practical experience
  • Experience with real-time operating systems
  • Experience debugging issues cross-functionally

Even better if you have experience in any of the following:

  • Experience with wireless protocols (e.g. BLE, NFC)
  • Experience using Python (or similar scripting languages) in automated testing, build systems, or device firmware communication

Additional Information

We’re working to build a more inclusive economy where our customers have equal access to opportunity, and we strive to live by these same values in building our workplace. Block is a proud equal opportunity employer. We work hard to evaluate all employees and job applicants consistently, without regard to race, color, religion, gender, national origin, age, disability, veteran status, pregnancy, gender expression or identity, sexual orientation, citizenship, or any other legally protected class. 

We believe in being fair, and are committed to an inclusive interview experience, including providing reasonable accommodations to disabled applicants throughout the recruitment process. We encourage applicants to share any needed accommodations with their recruiter, who will treat these requests as confidentially as possible. Want to learn more about what we’re doing to build a workplace that is fair and square? Check out our I+D page

Additionally, we consider qualified applicants with criminal histories for employment on our team, assessing candidates in a manner consistent with the requirements of the San Francisco Fair Chance Ordinance.


We want you to be well and thrive. Our global benefits package includes:

  • Healthcare coverage
  • Retirement Plans
  • Employee Stock Purchase Program
  • Wellness perks
  • Paid parental leave
  • Paid time off
  • Learning and Development resources

Block, Inc. (NYSE: SQ) is a global technology company with a focus on financial services. Made up of Square, Cash App, Spiral, TIDAL, and TBD54566975, we build tools to help more people access the economy. Square helps sellers run and grow their businesses with its integrated ecosystem of commerce solutions, business software, and banking services. With Cash App, anyone can easily send, spend, or invest their money in stocks or Bitcoin. Spiral (formerly Square Crypto) builds and funds free, open-source Bitcoin projects. Artists use TIDAL to help them succeed as entrepreneurs and connect more deeply with fans. TBD54566975 is building an open developer platform to make it easier to access Bitcoin and other blockchain technologies without having to go through an institution.

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