As a Senior Backend Engineer, you will play a pivotal role in designing, developing, and maintaining production-grade platforms for global clients. This position is at the heart of our development efforts, contributing significantly to the backbone of client-facing solutions. Youll be part of a dynamic development team, sized between 3 to 9 members, dedicated to craft scalable and resilient backend systems.
responsibilities :
Developing complex digital platforms - from architecture decisions to implementation and deployment.
Work in autonomous teams (3-9 people) delivering mission-critical systems.
Collaborate directly with technology leaders, founders, and domain experts to shape solutions that drive real business outcomes.
requirements-expected :
Extensive commercial experience in building web-based application (+5 years).
Strong proficiency in at least one of Upside’s core technology stack: Ruby, Python, JavaScript, Node or the willingness to learn based on your current skills.
Solid understanding of software architecture principles: monoliths, microservices, asynchronous systems, messaging patterns, and scalability.
Deep knowledge of relational databases (we mostly use PostgreSQL) and performance optimization.
Working understanding of frontend frameworks and tools (e.g. Vue.js, React.js).
Practical experience with Continuous Integration/Continuous Deployment (CI/CD) practices and modern cloud environments.
Strong consulting mindset - balancing technical excellence with client needs and communicating effectively with both technical and non-technical stakeholders.
Fluent English, with clear written and verbal communication.
offered :
Salary: Senior Engineer: 20 800 - 25 900 PLN net + VAT / Lead Engineer: >26 500 PLN net + VAT.
Transparent progression path.
Flexible work: office in Kraków, hybrid or remote from anywhere in Poland, with company on-sites.
Additional paid days off beyond national holidays.
A deeply collaborative, engineering-led company culture.
Support for ongoing learning.
benefits :
sharing the costs of sports activities
private medical care
sharing the costs of foreign language classes
sharing the costs of professional training & courses
