Principal Engineer, Card Readers Team

Toast

18h•$180,000 - $368,000•Hybrid

About The Position

Toast creates technology to help restaurants and local businesses succeed in a digital world, helping business owners operate, increase sales, engage customers, and keep employees happy. As a Principal Engineer on the Card Readers team, you will be a technical leader responsible for designing, developing, and maintaining our POS payment integrations. You will work closely with hardware SDKs, the core POS application team, and other cross-functional stakeholders to drive technical decisions and define the target architecture for our payment solutions. Your expertise in high-throughput asynchronous JVM solutions, coupled with a deep understanding of mission-critical transactional processing, will be crucial in delivering robust and scalable solutions.

Requirements

Demonstrated ability to lead large, cross-team platform initiatives, setting technical direction beyond a single team or service
Expert-level proficiency in Kotlin, Java, and/or JVM languages, including high-scale successes with multi-threading/concurrency (deep experience with coroutines a plus)
Fluency with card payments, particularly EMV standards and technology.
Experience working in a large (Android) project/codebase, architecting for clear domain boundaries, modularity, reusability, and testability
Track record of complex and robust SDK integrations completed successfully
Expertise in security and key management best practices
Experience designing public APIs for hassle-free consumption
Expertise in observability, monitoring, and alerting for complex user-device interactions
Strong skills in mentoring a team of developers on best practices
Openness and enthusiasm for AI tooling to enhance R&D productivity
Excellent communication, collaboration, and problem-solving skills that lead others by example

Nice To Haves

Low-level hardware/device integration experience, and/or experience with hardware abstraction
Experience working with third-party payment gateways, in-app purchases, POS integrations, or other aspects of fintech

Responsibilities

Develop and execute technical strategies to solve complex business challenges, leveraging data and customer insights to prioritize impactful improvements.
Establish guiding technical and delivery principles that influence engineering practices across the broader engineering organization.
Architect, design, and develop robust, high-performance applications using Kotlin, optimized for security, speed, availability, and reliability.
Raise the bar as a high-throughput, hands-on code contributor modeling high standards.
Lead agile development processes, including sprint planning, daily stand-ups, and retrospectives.
Mentor and guide engineers, fostering a culture of continuous improvement, inclusivity, and engineering excellence.
Build and maintain strong partnerships across lines of business, aligning technical solutions with strategic objectives.
Leverage cutting edge AI tools to enhance your development workflow, improve velocity, and help pioneer new approaches to building - contributing to a culture of innovation and productivity across the team.