Senior Backend Software Engineer - Cracow/Paris/Lyon

Senior Backend Software Engineer

Location: Kraków (Hybrid)

The role

We are looking for a Senior Backend Software Engineer to design and build scalable backend systems that power critical parts of our platform. In this role, you will help shape the technical direction of backend systems within the tribe, drive complex initiatives across teams, and ensure our architecture remains scalable, maintainable, and secure as the platform grows.

You will take ownership of systems throughout their lifecycle—from design and development to deployment and operations—while mentoring engineers and contributing to engineering standards across the tribe.

Team

People & Growth Tribe. The tribe focuses on building solutions that help employees grow, stay engaged, and easily interact with HR processes. Within the tribe, your team focuses primarily on HR workflows and employee onboarding experiences.

What you will do

• Design, build, and maintain scalable backend services.
• Help shape the architecture and technical direction of backend systems within the tribe.
• Drive technical initiatives that span multiple teams.
• Write clean, maintainable, and well-tested code.
• Deploy, monitor, and optimize services in production.
• Collaborate with product managers, designers, QA, and engineers to deliver impactful features.
• Mentor engineers and promote strong engineering practices.
• Identify and address technical debt and foundational improvements.
• Help maintain reliable and secure systems, including participation in on-call rotations.

Backend engineering experience

• Strong experience with Java or Python.
• Experience building microservices and distributed systems.
• Experience designing and building REST APIs.
• Experience with relational databases such as PostgreSQL or MySQL.

Cloud‑native systems

• Experience with Docker and Kubernetes.
• Experience building systems in AWS, GCP, or Azure.

Architecture & technical leadership

• Ability to design scalable and maintainable systems.
• Experience driving technical decisions across teams.
• Strong system‑level thinking and ability to evaluate architectural trade‑offs.
• Experience mentoring engineers and guiding design discussions.

Engineering mindset

• Strong ownership and attention to detail.
• Commitment to code quality, testing, and maintainability.
• Pragmatic problem solver focused on delivering value.
• Strong communication skills in English.

Nice to Have

• Event‑driven architectures (Kafka, RabbitMQ).
• Data streaming or processing systems (Debezium, ClickHouse).
• Authentication and authorization (SAML, OAuth2, OIDC).
• Observability tools (Prometheus, Grafana, Datadog, ELK).
• Experience building large‑scale SaaS platforms.
• Exposure to AI or LLM integrations.

Our Tech Environment

• Backend: Java, Python.
• Frameworks: Quarkus, Flask.
• Architecture: Microservices, event‑driven systems.
• Databases: PostgreSQL, MySQL, Redis, ClickHouse.
• Messaging: Kafka, RabbitMQ.
• Infrastructure: Docker, Kubernetes.
• Cloud: AWS, GCP, Azure.

Why You’ll Love Working at LumApps

• Phone & Home Internet costs reimbursement up to 80 PLN/month.
• Private health care package with Luxmed – covered for you and partially for your partner / family.
• Cafeteria benefits – monthly budget to cover sport cards or other purchases.
• Creative Allowance – paid as 1000 PLN gross/month.
• Home office set‑up reimbursement up to 1000 PLN.
• 26 days of annual leave/year and 2 Mental Health days off per year.

EEO Statement

We aim to celebrate diversity and are committed to creating an inclusive environment for all employees. We encourage applications from candidates of all backgrounds, identities, and experiences. Benefits listed above are part of the compensation package for contract of employment.