Senior Backend Engineer (Data serving)

ABOUT PLEO Messy spend management is tricky business. And tedious processes are a lose-lose situation for all involved, not just finance. At Pleo, we're changing that. We build spend solutions that make managing money seamless, empowering, and surprisingly effective for finance teams and employees alike - with a vision to help all businesses ‘go beyond’. The word ‘Pleo’ actually means ‘more than you’d expect’, and living by that mantra has been the secret to our success over the last 10 years. Now, we’re at a pivotal moment in our journey; every move we make has a direct impact on our 40,000+ customers, our business, and our collective success. We need people who take pride in uncovering customer needs, who turn complex problems into simple solutions, challenge the way things are done (respectfully), and always aim high. With great ambitions driving us forward, we can’t say we’ve got this whole thing figured out. And frankly, that’s half the fun! What we can say is that we’re a driven, progressive, and, importantly, a kind bunch of 850+ people from over 100 nationalities, all committed to delivering the future of business spending, together. Please note: applications will be open until Tuesday 13th October 2026 at 08.00 CEST. We will not review any application before the closing date so please use this time to submit a high quality application. ABOUT THE ROLE We're looking for a Senior Backend Engineer to join the Data Serving team that owns the production-grade boundary between Pleo's raw product data and everyone who consumes it, including internal product teams, AI agents, and customers directly accessing their own data. This Senior Backend Engineer role builds and owns that boundary: APIs and the low-latency serving layer underneath it. You will build customer-facing infrastructure where contract stability and latency are non-negotiable, and where the clean abstraction you maintain is what lets every downstream consumer trust the data without ever touching a raw source. WHO YOU’LL BE WORKING WITH AND REPORTING TO You will report to our Senior Manager of Data & AI Products, and work closely with our Staff Data Platform Engineer, Data Engineers, Product Managers and others Engineers across the business. You'll also coordinate closely with the GenAI Platform and Data Infrastructure teams. WHAT YOU’LL BE DOING As a Senior Backend Engineer, you will: - Build and own the Data API boundary: delivering clean, versioned, and performant endpoints for internal dashboards, customer-facing features, and third-party tools (e.g., Fivetran connectors via incremental syncs and cursor pagination). - Design and optimise the read models, indexes, and caching strategies in Postgres (and future OLAP stores) to guarantee low-latency query performance. - Build reliable integrations with Pleo’s Kotlin-based product backend services to ensure the serving layer surfaces the correct data required for a customer facing feature. - Own the reliability and performance of the services you build: monitoring, incident response, and SLOs appropriate to customer-facing infrastructure. - Partner with Data Engineers to define clean contracts between the ingestion/aggregation layer and the serving DB, ensuring read patterns match storage schemas. - Partner with the Authorization team to secure APIs using industry-standard authentication and authorization protocols. - Build a near-real-time data aggregation service to collect and unify data across Pleo services. - Design metadata, lineage, and governance capabilities that make the serving layer explainable, auditable, and trustworthy. - Own access control and permission management services, including row and column-level data access with full audit trails. To put things into context, you can expect to work with the following tech stack: AWS (product side), GCP (data side), Docker, Kubernetes, BigQuery, PostgreSQL dbt, Kafka, Airflow, Python, Kotlin and more! WHAT YOU BRING You’ll thrive in this role if you have: - Strong backend engineering experience building and owning reporting and analytics API services and serving-layer infrastructure. - A mindset focusing on reliability, latency, and SLOs. - Experience owning API boundary layers including clean endpoint design, versioning, contract stability, and ensuring downstream consumers are never exposed to raw data sources. - Strong expertise designing performant read-heavy systems, including relational database optimisation, indexing strategies, materialised views, caching, and API performance tuning. - Solid database fundamentals (SQL and non-SQL) and strong SQL querying skills, as well as deep expertise in Kafka. - Deep experience with a JVM-based language (Pleo's product backend is Kotlin-based). - AWS or GCP with Kubernetes experience. You must be familiar with configuring, deploying and operating containerised applications in a k8s environment. - Experience working at the boundary between data systems and product backend services, with a real understanding of the operational differences between the two. - The ability to move quickly and independently. This is a hands-on delivery role with clear scope, not an architecture or advisory engagement. - Experience in fintech, payments, or other regulated product environments. WHY IS THIS ROLE A GOOD FIT FOR YOU This role is a good fit for you if: - You are passionate about building systems that serve other engineers. - You understand what it means to design, build and maintain services with high performance, availability and reliability requirements. - You have a very deep understanding of the data world and know how to bridge the gap between data and engineering. This role is not a good fit for you if: - You need to operate within very large and structured teams with clear hierarchy. This role sits within a small and specialist team with a lot of autonomy. - You do not wish to be responsible for