Senior Kotlin Backend Engineer

Flixbus Flixtrain — Germany · Posted ~1 hour ago

Senior Full-time

Skills

Kotlin Spring Boot REST APIs backend development software architecture CI/CD cloud observability performance optimization reliability engineering REST DataDog

🔓 Log in to save this job, tailor your resume & track your apply process — 7 days free, no card needed.

Log in to add to target list

Summary ✨ AI‑Generated

As a Senior Kotlin Backend Engineer, design and develop scalable backend services and REST APIs while contributing to architectural decisions and modernization. You will improve system observability, performance, and reliability and participate in cloud and CI/CD initiatives within an AI-native engineering environment.

Highlights

Senior backend role with strong ownership, architectural influence, modernization work, cloud technologies, observability, and an AI-native development environment.

Description

At Flix, we offer a tech-driven environment where innovation meets real-world impact, with competitive pay, strong growth opportunities, and a culture of collaboration and ownership. B2B Sales & Distribution team in Demand Division builds and operates the backend platform powering Flix's partner-facing ecosystem — including a self-management platform for partners, a back office portal for internal users, and an AI agentic bot supporting partner operations. As a Senior Kotlin Backend Engineer (m/f/d), you can make an impact by supporting a significant modernization of backend architecture and working in an AI-native development environment. About The Role Design and develop backend services in Kotlin and Spring BootBuild and maintain REST APIs used by internal and external partnersParticipate in architectural decisions and technical modernization initiativesImprove observability, performance, and reliability of backend systems using DataDogContribute to CI/CD pipelines and cloud infrastructure on AWS and KubernetesWork in and contribute to an AI-native development environment — including AI-integrated code review automation and an internal Claude Code plugin marketplace covering engineering standards: Kotlin/Spring Boot conventions, architectural patterns, testing practices, database guidelines, and team-specific conventions. About You 5+ years of professional backend development experience with JVM languages with at least 2 years of commercial experience with KotlinHands-on experience with Spring Boot Experience building and maintaining REST APIs and distributed systemsSolid SQL knowledge and relational database design, including MySQL and PostgreSQLSound software engineering fundamentals, clean code practices, and familiarity with ORM and persistence layersCollaborative and pragmatic, comfortable working in cross-functional Agile teamsPreferred: AWS, Kubernetes, GitLab CI/CD, Kafka, Terraform, LLM integrations, RAG systems, AI product development, or legacy system migration experience We recognize that everyone carries a unique set of valuable skills and experiences. If you think you could have an impact even though you don't meet 100% of the requirements, we still encourage you to apply. We want to hear from you! What We Offer Travel perks: 12 free Flix vouchers + 12 discount vouchers for friends & family. Work from (M)Anywhere: Depending on your role, work from another location for up to 60 days per year. Hybrid work model: We are an office-first company, but we offer flexibility to balance work and life. Wellbeing support: Access confidential 1:1 counselling, courses, and stress management for yourself and up to four family members. Learning & Development: Take advantage of language classes, training courses, and expert-led sessions to grow your skills. Mentoring Program: Connect with experienced colleagues to gain insights and accelerate your career. To view more local benefits specific to each office location, please check out this link: Locations - Flix Career Why Join Flix? At Flix, we empower our teams to push boundaries and shape the future of mobility. As we continue to scale globally, we harness cutting-edge technology to make mobility smarter, more sustainable, and more affordable. If you’re looking for a place where you can drive change and redefine how millions of people travel, Flix is the place where you can lead your journey!