Senior Kotlin Engineer, Card Payments Platform

Toast; Dublin; Hybrid; EUR 90,000 - 120,000; Full time

Benefits offered by this job

Hybrid work model

Total rewards package

Job summary

Toast is seeking a Senior Software Engineer for the Card Readers team in Dublin to design, develop, and maintain high-throughput payment integrations on our Kotlin/Java JVM stack. You’ll work closely with hardware SDKs, the core POS app team, and cross-functional partners to deliver fast, secure, and scalable payments.

You’ll mentor engineers, participate in agile processes, and ensure PCI-DSS compliance while exploring AI-assisted tooling to boost R&D productivity.

Qualifications

• Expert-level proficiency in Kotlin, Java, and JVM languages.
• Deep knowledge of multi-threading and coroutines.
• Experience in large Android projects with modular architecture.
• Experience designing public APIs and SDK integrations.
• Strong mentoring and collaboration skills.
• Openness to AI tooling for R&D productivity.

Responsibilities

• Design, develop and roll out high-performance Kotlin apps.
• Lead technical discussions on best practices and security.
• Collaborate with backend, product, UX/UI, QA to deliver payments.
• Optimize mobile payment flows for security and speed.
• Ensure PCI-DSS and financial industry standards compliance.
• Mentor junior engineers and perform code reviews.
• Troubleshoot issues to ensure high availability.
• Participate in agile sprint planning and stand-ups.
• Stay updated with emerging technologies.

Skills

Kotlin

Java

Multithreading

SDK integrations

API design

Observability

Mentoring

AI tooling

Tools

Android SDK

Job description

Toast is seeking a Senior Software Engineer for the Card Readers team in Dublin to design, develop, and maintain high-throughput payment integrations on our Kotlin/Java JVM stack. You’ll work closely with hardware SDKs, the core POS app team, and cross-functional partners to deliver fast, secure, and scalable payments.

You’ll mentor engineers, participate in agile processes, and ensure PCI-DSS compliance while exploring AI-assisted tooling to boost R&D productivity.