Staff Software Engineer - Data Platform

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. We are hiring a Staff Software Engineer to join our data platform (AAP) team in Dublin. The AAP team owns the foundational data infrastructure that powers Toast's analytics products and AI/ML capabilities: real-time streaming pipelines, a cloud-native data lakehouse, feature serving for ML-driven product experiences, and the infrastructure that enables product teams across Toast to build intelligent, data-driven experiences for our 170,000+ restaurant customers. We are in the middle of a significant platform evolution: migrating to Apache Iceberg, standing up a new Feature Store, conducting Databricks evaluations, and scaling our streaming infrastructure to meet the demands of a rapidly growing business. As a Staff Software Engineer, you'll be the technical lead for major parts of this evolution. You'll design and lead the delivery of platform capabilities that several teams depend on, doing deep hands-on work and making design calls that account for streaming, storage, serving, and the teams consuming them. You'll be the go-to expert in your area of the platform, working with product and engineering partners inside and outside our line of business. You'll make the engineers around you better through mentorship, design reviews, and the example you set. Success looks like other engineering teams moving faster because of the platform you help build. A day in the life (Responsibilities) • Lead the delivery of significant data platform capabilities, from early design through production rollout, across the AAP team and the teams that depend on it • Work hands-on with Kotlin/Java, Spark, Iceberg, and our streaming infrastructure, diagnosing performance, reasoning through trade-offs, and writing the code that sets the pattern for others • Anticipate how requirements will change and design systems that can absorb that change, exploring the problem fully before settling on a solution • Evolve the platform's API surfaces so that engineers across Toast can self-service - adoption and ease-of-use are part of the job • Lead efforts that measurably improve platform quality, reliability, and observability for the teams and customers who depend on it • Mentor other engineers and raise the bar on engineering practices across the organisation • Use AI tooling as a genuine force multiplier in your day-to-day work and help the team do the same What you'll need to thrive (Requirements) • 5+ years in software engineering with a strong focus on data platforms or distributed systems, including technical leadership of projects involving more than one team • Proficiency in Java, Kotlin or other object-oriented language • Strong hands-on expertise in Apache Spark and Apache Iceberg (or similar) • Experience with streaming infrastructure (Apache Kafka, Apache Pulsar, or similar) and cloud-native data platforms on AWS • Experience building internal platforms and developer-facing abstractions - you think about your platform's users as carefully as product engineers think about end users • Databricks experience is a bonus but we care more that you understand what's running underneath it **This is a hybrid role requiring in-office collaboration two days per week in our Dublin office. ** Our tech stack Our data platform runs on AWS and spans Apache Iceberg for table format and lakehouse architecture, Apache Kafka and Pulsar for real-time streaming, Apache Spark for data processing, and DynamoDB and Postgres for operational data stores. We are migrating from legacy ETL patterns toward a modern, cloud-native data lakehouse and building out Feature Store capabil