CyberSec Client #3 | Full Stack Developer

SD Solutions; Warszawa; On-site; PLN 60,000 - 90,000; Full time

Job summary

SD Solutions is looking for a talented Full Stack Developer in Warsaw, Poland, for a security validation platform. You will develop backend services using Kotlin and modern frontends with React + TypeScript. Responsibilities include API design, Docker containerization, and database optimization.

Candidates should have 3-5 years of experience with strong Kotlin and React skills. Hands-on Docker experience and security awareness are essential. Join a company that helps security teams continuously test their defenses.

Qualifications

• 3–5+ years of professional experience in software development.
• Strong Kotlin/JVM backend skills; able to architect services independently.
• Hands-on Docker experience in production environments.

Responsibilities

• Develop backend services using Kotlin and modern frontends with React + TypeScript.
• Design and implement REST APIs and real-time communication layers.
• Containerize applications using Docker and orchestrate with docker-compose.

Skills

Kotlin/JVM backend skills

React/TypeScript frontend skills

Docker

REST API design

Database design and query optimization

Security awareness

Tools

PostgreSQL

Job description

On behalf of CyberSec Client #3, SD Solutions is looking for a talented Full Stack Developer

SD Solutions is a staffing company operating globally. Contact us to get more details about the benefits we offer.

Responsibilities

• Develop robust backend services using Kotlin (Spring Boot / Ktor) and build modern frontends with React + TypeScript.
• Design and implement REST APIs and real-time communication layers (WebSocket / SSE).
• Containerize and orchestrate applications using Docker and docker-compose, including advanced patterns like Docker-in-Docker and sidecar containers.
• Design and optimize PostgreSQL databases with focus on performance and scalability.
• Ensure high security standards (input validation, rate limiting, secure resource management).
• Take full ownership of features — from requirements gathering to production deployment.
• Write clear technical documentation and justify architectural decisions.
• Work independently in a fast-paced environment while maintaining high code quality.

Requirements

• 3–5+ years of professional experience
• Strong Kotlin/JVM backend skills; ability to architect services independently
• Solid React/TypeScript frontend skills
• Hands-on Docker experience in production (orchestration and programmatic management)
• Experience with REST API design and real-time communication (WebSocket/SSE)
• Database design and query optimization
• Security awareness (input validation, rate limiting, resource management)
• Ability to write technical documentation and explain architecture decisions
• Independent worker capable of taking tasks from requirement to production

About the company

A security validation platform that lets security teams continuously test their defenses by running automated, scenario-based attack simulations modeled on real-world threat actors. Teams can repeat assessments until vulnerabilities are resolved and track readiness over time.

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