Senior Scala Engineer

Job description

**Who are we** For more than 20 years, our global network of passionate technologists and pioneering craftspeople has delivered cutting-edge technology and game-changing consulting to companies on the brink of AI-driven digital transformation. Since 2001, we have grown into a full-service digital consulting company with 5500+ professionals working on a worldwide ambition. Driven by the desire to make a difference, we keep innovating. Fueling the growth of our company with our knowledge worker culture. When teaming up with Xebia, expect in-depth expertise based on an authentic, value-led, and high-quality way of working that inspires all we do. **About the Role** Xebia is looking for a Senior Scala Engineer to join a team building scalable, resilient backend systems. This is a consulting role embedded in a functional-first, Typelevel-based stack, where you'll help design and ship high-throughput services running on AWS. You'll work closely with client architects and Xebia's engineering team to drive technical decisions, raise the bar on code quality, and deliver solutions that hold up under real production load. **What You’ll Do** - Design and build high-throughput, low-latency services in Scala 3 using a modern functional stack (Typelevel-style: cats-effect, http4s, fs2). - Define and evolve type-safe, schema-driven APIs, with attention to clean data transformations and serialization. - Lead architectural discussions, making sound trade-offs between performance, maintainability, and delivery timelines. - Conduct code reviews focused on functional-programming idioms, effect safety, and long-term maintainability. - Design and manage AWS infrastructure as code, working with core services such as ECS, Lambda, and managed databases/caching layers, plus event-driven components (queues, schedulers, streaming). - Instrument services for observability and take ownership of production reliability and performance. - Build and maintain a strong automated test suite, including property-based and integration testing. - Produce technical proposals, architecture docs, and root cause analyses for client-facing decisions. - Mentor other engineers on functional programming patterns and effect-oriented system design. - Translate complex technical trade-offs into clear recommendations for both engineering and client stakeholders. - Support technical evaluations of other consultants when required, contributing to the assessment of skills and alignment with project needs. **What You Bring** **Core experience** - 5+ years of professional software development experience, with solid hands-on experience in Scala and functional programming. - Production experience with a Typelevel-style effect system and functional HTTP stack (e.g., cats-effect, http4s, fs2, or equivalents). - Experience designing type-safe, schema-driven APIs in enterprise settings. - Experience supporting high-throughput, production-grade JVM systems, including asynchronous/concurrent programming models. - Experience with observability and distributed tracing tooling. **Infrastructure & AWS** - Proficiency in AWS, with hands-on experience across compute, serverless, database, caching, and event-driven/streaming services (