Senior Full-Stack Developer - Scanz

Location: Remote Type: ContractorAbout ScanzScanz has been building real-time trading technology for nearly two decades, powering serious traders around the world. We specialize in complex, high-performance systems that operate at scale in the fintech and capital markets space.At Scanz, innovation is grounded in education, curiosity, and collaboration. We foster a culture of continuous self-improvement and actively encourage out-of-the-box thinking. Our distributed teams work closely together to build the next generation of financial software used by traders of all experience levels—from industry professionals to first-time investors.The RoleWe’re looking for a Senior Backend Developer to join our engineering team and help design, build, and scale robust server-side systems and data pipelines. You’ll work primarily with Kotlin and Spring WebFlux in a highly concurrent, event-driven environment processing millions of operations per day.Strong Kotlin experience is preferred, but we’re equally open to seasoned Java developers who are motivated and able to transition quickly to Kotlin.This is a core role with real ownership: you’ll help shape architecture decisions, performance strategy, and system reliability in a production-grade fintech platform.What You’ll DoDesign and implement server-side services using Kotlin, Java, and Spring WebFluxBuild and maintain fault-tolerant, high-throughput data pipelinesDevelop and maintain high-performance APIsCollaborate closely with frontend engineers to integrate user-facing featuresContribute to PostgreSQL schema design and optimizationImprove system throughput and reliability through profiling, tuning, and performance testingScale services horizontally in a cloud-native environmentIntegrate performance and reliability checks into CI pipelinesParticipate in weekly standups, code reviews, and architectural discussionsWhat We’re Looking ForStrong proficiency in Kotlin and/or JavaSolid experience with Kotlin coroutines and flowsDeep understanding of Spring WebFlux, Reactive Streams, and backpressureExperience building distributed, fault-tolerant systemsStrong problem-solving and analytical skillsComfortable working asynchronously across time zonesExcellent communication skills (Slack, Loom, async collaboration)Hands-on experience with:PostgreSQLAWS and cloud-native architecturesDocker and KubernetesStrong grasp of the testing pyramid (unit, integration, E2E)Willingness to actively participate in code reviews and technical discussionsBackend Tech StackKotlin, JavaSpring WebFlux, Ktor ServerKotlin CoroutinesRSocketKtor Clientkotlinx.serializationQuartzKotest, JUnitGradleFrontend Tech StackKotlin MultiplatformReact (Hooks)TypeScriptSharedWorkerNPMGradleInfrastructure & ToolingAWS (including S3)Docker & KubernetesPrometheus & GrafanaJenkinsGitHubOriginally posted on Himalayas