Senior Software Engineer (Android)

Toast; Ireland; On-site; EUR 110,000 - 140,000; Full time

Benefits offered by this job

Unlimited Vacation

Sabbatical after five years

Professional Development Reimbursement

Wellness Stipend

Recognition programs

401(k) and matching

Medical, Dental, & Vision Coverage

Subsidized backup childcare

Mental Health Benefits

Peer recognition programs

Job summary

Toast is seeking a Senior Software Engineer for the Card Readers team to ensure fast, reliable, and secure processing of millions of payments. You’ll design, develop, and maintain our POS payment integrations and work with hardware SDKs, the core POS app team, and cross-functional partners to drive architecture decisions.

You’ll specialize in high‑throughput asynchronous JVM solutions using Kotlin, mentor peers, lead performance and security best practices, and help shape development at Toast

Qualifications

• Excellent communication and collaboration across teams.
• Deep knowledge of multi-threading/concurrency and Kotlin/JVM.
• Experience with Android projects, modular architectures, and testability.
• Observability, monitoring, and alerting for complex interactions.
• SDK integrations with card payments and EMV experience.
• Security and PCI-DSS awareness; adherence to best practices.
• Mentoring developers, conducting code reviews, and guiding teams.

Responsibilities

• Design, develop, and maintain POS payment integrations.
• Collaborate with hardware SDKs, core POS app team, and cross-functional partners.
• Lead technical discussions on performance, security, and best practices.
• Triage issues and ensure high availability and reliability.
• Participate in agile processes and drive architectural decisions.
• Stay up to date with emerging technologies and trends.

Skills

High-throughput JVM

Kotlin

Security best practices

Code reviews

Multithreading / Concurrency

Observability

Android project experience

SDK integrations

Tools

Hardware SDKs

Job description

• As a Senior Software Engineer on the Card Readers team, it’s your job to make sure those millions of payments are processed quickly, reliably, and securely
• You will be a key team member 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 refine the target architecture for our payment solutions
• Your expertise in high-throughput asynchronous JVM solutions, coupled with a deep understanding of mission-critical transaction processing, will be crucial in delivering robust and scalable solutions
• Design, develop and roll out robust, high-performance applications using Kotlin
• Lead technical discussions and decisions on best practices, performance optimizations, and security
• Collaborate with cross-functional teams (backend, product, UX/UI, QA) to deliver seamless payment experiences
• Optimize mobile payment flows for security, speed, and reliability
• Shape the face of development at Toast by helping to balance building maintainable software for long term success, with the need to deliver value to customers in an iterative fashion
• Ensure compliance with PCI-DSS, security best practices, and other financial industry standards
• Mentor and guide junior engineers, conduct code reviews, and drive best practices in software development
• Troubleshoot and resolve complex technical issues, ensuring high availability and performance
• Participate in agile development processes, including sprint planning, daily stand-ups, and retrospectives
• Stay up to date with emerging technologies, frameworks, and trends

Benefits

• Peer and company recognition programs
• Unlimited Vacation
• Sabbatical opportunity after five years
• Professional Development Reimbursement Program
• Commitment to Employee Wellness through resources such as a quarterly Wellness Stipend
• Various peer and company recognition programs
• 401(k) and matching
• Medical, Dental, & Vision Coverage
• Subsidized backup childcare
• Mental Health Benefits

Excellent communication, collaboration, and problem-solving skills that lead others by exampleDeep knowledge of multi-threading/concurrency (experience with coroutines a plus)Openness and enthusiasm for AI tooling to enhance R&D productivityExperience working in a large (Android) project/codebase, architecting for clear domain boundaries, modularity, reusability, and testabilityExpertise in observability, monitoring, and alerting for complex user-device interactionsExperience designing public APIs for hassle-free consumptionStrong skills in mentoring fellow developers on best practicesTrack record of complex and robust SDK integrations completed successfullyExpert-level proficiency in Kotlin, Java, and/or JVM languagesCard Payments/EMV experienceHardware/device integration experienceSecurity and key management experience