Senior Fullstack Developer

SNI; Warszawa; Hybrid; PLN 180,000 - 240,000; Full time

Benefits offered by this job

Hybrid work

Office in Warsaw

Job summary

SNI sp. z o.o. in Warsaw, Poland, is seeking a Senior Fullstack Developer to design and build large-scale applications. This role emphasizes backend development with Java/Spring Boot and modern frontend work with SPA frameworks.

The position is full-time and hybrid, with 50% of work from the client’s Warsaw office. You will implement microservices, CI/CD pipelines, security measures, and collaborate with business stakeholders to deliver robust software.

Qualifications

• Proven experience with modern Java and Spring Boot.
• Strong background in building SPAs and frontend frameworks.
• Hands-on experience with microservices and Kafka.

Responsibilities

• Design, develop, and maintain fullstack applications with backend and frontend focus.
• Develop Java-based microservices using Spring Boot and SPA frontends.
• Collaborate with stakeholders to refine requirements and implement security.
• Build and maintain CI/CD pipelines and automated tests.
• Maintain documentation and participate in code reviews.

Skills

Java

Spring Boot

Kafka

SQL

Redis

Domain Driven Design

Node.js

TypeScript

Angular

Web Security

Git

CI/CD

GitLab CI

Job description

SNI is serving as a trusted IT Outsourcing partner in line with the needs of World's most prestigious firms and carried out successful projects worldwide.

For one of our clients, we are currently looking for a Senior Fullstack Developer.

Job details

• Role: Senior Fullstack Developer
• Full-time
• Hybrid (50% from the client’s office in Warsaw. Not calculated as days in a week but days in a month)
• End date: 31/12/2026 + extension planned

Scope

• Design, develop, and maintain fullstack applications with a strong emphasis on backend and modern frontend architectures.
• Build high-quality, maintainable, secure, scalable, and testable software, aligned with business requirements.
• Develop and evolve Java-based microservices using Spring Boot.
• Contribute to Single Page Applications (SPA) development, ensuring best practices are followed on the frontend.
• Collaborate with business and technical stakeholders to clarify and refine functional and non-functional requirements.
• Participate in solution design, pre-project studies, and technical decision‑making.
• Integrate systems using event‑driven architectures and streaming platforms.
• Optimize and maintain existing codebases.
• Implement, execute, and maintain automated tests and CI/CD pipelines.
• Ensure application security, including identity management and secure authentication flows.
• Maintain and update technical documentation.
• Participate in internal and external developer communities to share best practices.
• Continuously improve skills in modern technologies and software engineering practices.

Skills

• Java 17–21 – strong hands‑on experience with recent versions (focus on modern Java, no legacy Java work).
• Spring Boot 3.x – with a strong emphasis on microservices architectures.
• Kafka – required experience with event‑driven or messaging‑based systems.
• SQL (Oracle) – strong practical experience.
• Redis – experience or strong understanding expected.
• Experience with Domain Driven Design
• Node.js – required.
• TypeScript – required.
• Angular – solid experience building SPAs (framework version is not critical).
• Strong understanding of web application security.
• Git – required.
• CI/CD: Jenkins (nice to have), GitLab CI.

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