Fullstack Engineer, Spark

Lightspark is building open payments for the Internet—always-on payment solutions powered by Bitcoin, the only open, neutral network for moving value. With enterprise tools like Connect, UMA, and Spark, businesses can send and receive money instantly, securely, and at a fraction of the cost, anytime, anywhere. Lightspark is headquartered in Los Angeles, California, but serves the world.

Spark ( spark.money ) is building the future of scalable Bitcoin payments. We launched a Bitcoin-native Layer 2 for payments that delivers the fastest, simplest, and cheapest rails in crypto while enabling native, scalable, self-custodial assets like BTC and stablecoins. We are looking for a fullstack engineer to join our Spark SDK team. You’ll have the opportunity to work across multiple languages and platforms, creating SDKs for our global partners that will power the next generation of payment applications. We’re looking for engineers who thrive in high-intensity environments, can adapt quickly, are excited to build on cutting-edge Bitcoin infrastructure, and have fun along the way.

WHAT YOU’LL BE DOING:

• Design, build, and maintain SDKs used by our partners to integrate with Spark’s backend services

• Work across multiple languages and platforms, primarily JavaScript/TypeScript now, with new SDKs in Kotlin, Go, and others as we expand

• Build core functionality and developer tools that will be used by high-volume enterprise customers

• Collaborate with other engineers, product managers, and partner teams to deliver reliable, high-quality software

• Ensure SDKs are well-tested, well-documented, and easy for developers to adopt

• Contribute to the architecture and design of new features, ensuring scalability and performance

• Adapt quickly to new technologies, languages, and requirements as the product evolves

• Maintain a high bar for engineering excellence in a fast-paced, collaborative environment
  

WHAT WE’RE LOOKING FOR:

• 3+ years of fullstack engineering experience

• Strong experience with JavaScript/TypeScript

• Willingness and ability to work across multiple languages (e.g., Kotlin, Go)

• Experience building SDKs, APIs, or developer tools is a plus

• Experience with React Native and/or mobile development is a plus

• Crypto, fintech, or side project experience is a plus (Bitcoin/Lightning background not required—ability to ramp quickly is key)
  Proven ability to work independently and deliver high-quality results under tight timelines

• Adaptability and resourcefulness in solving problems across unfamiliar tech stacks

• Strong collaboration skills and a proactive approach to driving initiatives forward

• Bachelor's degree in Computer Science, or equivalent is a plus but not required. We appreciate and acknowledge that some of the best talent comes from non-traditional backgrounds

• Living in, or willing to relocate, to Los Angeles, CA, we are an in-office company located in Culver City

Lightspark is on a mission to build an open payment protocol for the Internet at scale and therefore we’re committed to creating a more inclusive and diverse workplace to reflect the customers we serve. We welcome interest from individuals of all backgrounds and levels of experience who share our mission. We do not discriminate based on race, religion, color, national origin, gender, sexual orientation, age, marital status, veteran status, disability status, or other applicable legally protected characteristics.

We will consider for employment qualified applicants with criminal histories in a manner consistent with the requirements of the State of California Fair Chance Initiative for Hiring.