Senior Full-Stack Developer - Scanz

Location: Remote
Type: Contractor

About Scanz

Scanz 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 Role

We’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 Do

• Design and implement server-side services using Kotlin, Java, and Spring WebFlux

• Build and maintain fault-tolerant, high-throughput data pipelines

• Develop and maintain high-performance APIs

• Collaborate closely with frontend engineers to integrate user-facing features

• Contribute to PostgreSQL schema design and optimization

• Improve system throughput and reliability through profiling, tuning, and performance testing

• Scale services horizontally in a cloud-native environment

• Integrate performance and reliability checks into CI pipelines

• Participate in weekly standups, code reviews, and architectural discussions

What We’re Looking For

• Strong proficiency in Kotlin and/or Java

• Solid experience with Kotlin coroutines and flows

• Deep understanding of Spring WebFlux, Reactive Streams, and backpressure

• Experience building distributed, fault-tolerant systems

• Strong problem-solving and analytical skills

• Comfortable working asynchronously across time zones

• Excellent communication skills (Slack, Loom, async collaboration)

• Hands-on experience with:

  • PostgreSQL

  • AWS and cloud-native architectures

  • Docker and Kubernetes

• Strong grasp of the testing pyramid (unit, integration, E2E)

• Willingness to actively participate in code reviews and technical discussions

Backend Tech Stack

• Kotlin, Java

• Spring WebFlux, Ktor Server

• Kotlin Coroutines

• RSocket

• Ktor Client

• kotlinx.serialization

• Quartz

• Kotest, JUnit

• Gradle

Frontend Tech Stack

• Kotlin Multiplatform

• React (Hooks)

• TypeScript

• SharedWorker

• NPM

• Gradle

Infrastructure & Tooling

• AWS (including S3)

• Docker & Kubernetes

• Prometheus & Grafana

• Jenkins

• GitHub