Remote Kotlin / Java Backend Developer

Scanz; España; A distancia; EUR 50.000 - 70.000; Jornada completa

Descripción de la vacante

A fintech company in Spain is seeking an expert Backend Developer to join their team. The role involves designing server-side applications using Kotlin and Spring Webflux, building robust data pipelines, and maintaining APIs. Ideal candidates will have strong problem-solving skills and experience with distributed systems. Attractive career development opportunities offered.

Servicios

Excellent career development opportunities

Work alongside best-in-class talent

Formación

• Expert-level experience in backend development.
• Familiarity with building scalable data pipelines.
• Strong background in working with distributed systems.

Responsabilidades

• Design and implement server-side logic using Spring Webflux and Kotlin.
• Build fault-tolerant data pipelines that process millions of operations daily.
• Develop and maintain APIs for high performance.

Conocimientos

Strong proficiency in Kotlin/Java

Proficiency with Kotlin coroutines (flows)

Proficiency with Spring Webflux

Strong problem-solving skills

Excellent collaboration skills

Herramientas

PostgreSQL

Docker

Kubernetes

Descripción del empleo

Scanz has been working for nearly two decades in the real-time trading technology and fintech space. We deliver complex technological systems that enable serious traders worldwide.

By joining Scanz, you’ll become a part of a company that fosters self‑improvement and actively seeks out‑of‑the‑box ideas. Our teams work together to create the next generation of financial software solutions. We welcome all candidates who believe, as we do, that innovation is grounded in education.

The Role

We are seeking an expert‑level Backend Developer to join our dynamic team and contribute to the development of robust, scalable server‑side applications and data pipelines. You will primarily work with Spring Webflux and Kotlin (and Java). Although existing expertise in Kotlin is preferred, a deep understanding of Java is acceptable if there’s a willingness to adapt and transition quickly.

Scanz is a leading SaaS Trader Terminal that provides a suite of real‑time trading tools to help traders and investors identify live trading opportunities in the US stock market. We are dedicated to offering our users – from trading pros to absolute beginners – an intuitive and efficient trading experience.

Responsibilities

• Design and implement server‑side logic using Spring Webflux and Kotlin.
• Build robust, reliable, fault‑tolerant data pipelines that process millions of operations daily.
• Collaborate with front‑end developers to integrate user‑facing elements with server‑side logic.
• Develop and maintain APIs, ensuring high performance and responsiveness.
• Contribute to database design and implementation (PostgreSQL).
• Improve the system’s throughput and incorporate performance testing into our CI pipelines.
• Scale services horizontally.
• Contribute to weekly standup.

Back End Tech Stack

• Kotlin
• Spring Webflux
• Ktor Server
• Kotlin Coroutines
• RSocket
• Ktor Client
• Kotlinx Serialization
• Quartz
• Kotest + JUnit
• Gradle

Front End Tech Stack

• Kotlin Multiplatform
• React (with hooks)
• SharedWorker
• TypeScript
• NPM
• Gradle

Infrastructure

• AWS + S3
• Prometheus
• Grafana
• Jenkins
• Github

Ideal Profile

• Strong proficiency in Kotlin / Java.
• Proficiency with Kotlin coroutines (flows).
• Proficiency with Spring Webflux and Reactive Streams back pressure.
• Self‑motivated developer comfortable working as a core member on an A‑list team of backend and frontend developers split over different time zones.
• Strong problem‑solving and analytical skills.
• Excellent collaboration and communication skills within an asynchronous environment (Slack, Loom).
• Deep‑level understanding of distributed systems and how to make fault‑tolerant applications.
• Experience with containerization technologies (Kubernetes, Docker).
• Strong familiarity with database systems, particularly PostgreSQL.
• Comfortable using AWS and cloud computing platforms.
• Solid understanding of the testing pyramid, specifically unit, integration, and E2E tests.
• Readiness and desire to participate in code reviews.
• Familiar with AI tools like Claude Code.

What’s on Offer?

• Work within a company with a solid track record of success
• Work alongside & learn from best in class talent
• Excellent career development opportunities