Senior Staff Software Engineer

Day-to-day Reponsibilities

• Design, build, and maintain Java/Spring and Kafka Streams-based services processing real-time BLE and IoT telemetry at scale
• Own ingress integrations with third-party location platforms — from protocol understanding to production reliability
• Build egress pipelines streaming location and event data to downstream systems via REST, gRPC, and WebSocket
• Drive architectural decisions and document them — the team currently operates on verbal agreements; you will change that
• Use AI tools as a core part of your development workflow: code generation, debugging, documentation, prototype acceleration
• Define and enforce testing standards using Testcontainers and CI pipelines (Jenkins, GitHub Actions)
• Instrument services with Prometheus and Micrometer; build Grafana dashboards that give the team real operational visibility
• Collaborate with Data Platform and SRE teams on Kafka topology, state store configuration, and infrastructure ownership
• Mentor engineers on the team — through code reviews, design sessions, and honest feedback

What we are looking for

• 7+ years of backend software engineering, with strong production Java experience — Spring Boot and ideally Kotlin too
• Deep, hands-on Apache Kafka knowledge: Streams, state stores, topology design, and operational behavior — not just produce/consume
• Experience building real-time, event-driven distributed systems in multi-tenant SaaS environments
• Solid database fluency: MongoDB, PostgreSQL, Redis — you know when to use what and why
• Hands-on AWS experience: EKS, Kinesis, S3; comfortable reading and writing Terraform and Helm
• Track record of taking ownership of a messy, under-documented domain and making it better
• Ability to work directly with product and business stakeholders — you can translate between engineering and everything else
• Clear written and verbal English; the team is international
• Based in or willing to relocate to Kraków, Poland

Nice to have

• Experience with IoT or BLE telemetry systems
• Go or Python for tooling and automation
• Familiarity with AsyncAPI, Drools rules engine, or OAuth2/Keycloak
• Background in a high-growth Series B/C product company

The kind of Engineer we are hiring

You should be comfortable with ambiguity, allergic to sloppiness, and capable of holding a high bar while still shipping. If you think AI tools are optional extras rather than a core part of how modern engineers work, this is not the right role.

We Offer

Competitive salary reflecting staff-level seniority — we benchmark against market

Equity in a Series C company with a clear growth trajectory