Staff Software Engineer (Backend)

TL;DR

Staff Software Engineer (Backend): Own the full data ingress and egress pipeline for IoT real-time location platform processing BLE telemetry with an accent on third-party device integrations, Kafka Streams, and streaming to external APIs. Focus on driving architectural evolution, enforcing engineering standards, and scaling event-driven systems in multi-tenant SaaS environments.

Location: Hybrid from Kraków office - at least 2 days in the office. Based in or willing to relocate to Kraków, Poland.

Company

Leading IoT platform for real-time location and telemetry in healthcare and enterprise, trusted by major U.S. health systems and backed by Goldman Sachs.

What you will do

• Design, build, and maintain Java/Spring and Kafka Streams services processing high-volume real-time BLE and IoT telemetry.
• Own ingress integrations with third-party platforms like Cisco Spaces and Aruba for reliable data ingestion.
• Build egress pipelines streaming enriched location data to downstream systems via REST, gRPC, and WebSocket.
• Drive architectural decisions, documentation, testing standards with Testcontainers, and observability with Prometheus/Grafana.
• Collaborate with product, Data Platform, and SRE teams to resolve dependencies and align on requirements.
• Mentor engineers through code reviews, design sessions, and feedback.

Requirements

• 7+ years backend engineering with strong production Java/Spring Boot experience (Kotlin a plus)
• Deep hands-on Apache Kafka: Streams, state stores, topology, operations.
• Experience with real-time event-driven distributed systems in multi-tenant SaaS.
• Database fluency: MongoDB, PostgreSQL, Redis.
• Hands-on AWS: EKS, Kinesis, S3; Terraform, Helm.
• Clear written and verbal English; international team
• Based in or willing to relocate to Kraków, Poland

Nice to have

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

Culture & Benefits

• Competitive staff-level salary benchmarked to market plus equity in Series C company.
• Private healthcare, Multisport card, standard benefits.
• Hybrid work from Kraków office.
• Use AI tools as core part of development workflow.
• Real technical challenges in scaling platform.