Senior Staff Software Engineer

Kontakt.io is the leading IoT platform for real-time location and telemetry in healthcare and enterprise. Their systems monitor hundreds of thousands of assets and people across hospitals and campuses globally, processing billions of BLE events daily through a Kafka-first, cloud-native architecture. The company is backed by Goldman Sachs and trusted by leading health systems such as HCA Healthcare, Sutter Health, AdventHealth, and others. They are pioneering healthcare operations with a focus on combining proprietary hardware, AI-powered intelligence, and deep system integrations.

• 7+ years of backend software engineering experience with strong production Java expertise
• Proficiency in Spring Boot and preferably Kotlin
• Deep hands-on knowledge of Apache Kafka Streams, state stores, topology design, and operational behavior
• Experience building real-time, event-driven distributed systems in multi-tenant SaaS environments
• Solid database experience with MongoDB, PostgreSQL, and Redis
• Hands-on AWS experience including EKS, Kinesis, and S3; comfortable with Terraform and Helm
• Track record of taking ownership of complex, under-documented domains and improving them
• Ability to work directly with product and business stakeholders and translate requirements
• Proficient in written and verbal English (C1 level)
• Based in or willing to relocate to Kraków, Poland

Nice to have:

• Experience with IoT or BLE telemetry systems
• Experience with 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

• Design, build, and maintain Java/Spring Boot and Kafka Streams-based services processing real-time BLE and IoT telemetry at scale
• Own ingress integrations with third-party location platforms such as Cisco and Aruba
• Build egress pipelines streaming location and event data to downstream systems via REST, gRPC, and WebSocket
• Drive architectural decisions and document them to replace current verbal agreements
• Use AI tools for code generation, debugging, documentation, and prototype acceleration
• Define and enforce testing standards using Testcontainers and CI pipelines (Jenkins, GitHub Actions)
• Instrument services with Prometheus and Micrometer; build Grafana dashboards for operational visibility
• Collaborate with Data Platform and SRE teams on Kafka topology, state store configuration, and infrastructure
• Mentor engineers through code reviews, design sessions, and feedback

Data ingress & device integration:

• Own the pipeline for external device data ingestion
• Integrate with infrastructure like Cisco Spaces and Aruba

Data egress & external integrations:

• Stream enriched data to partner systems and APIs with standards-compliant adapters

Architecture & technical leadership:

• Lead architectural evolution, stabilize and sequence rewrites without production impact
• Establish and uphold engineering standards for documentation, testing, and observability

Cross-team ownership:

• Translate business requirements into engineering decisions
• Clarify scope and resolve dependencies blocking the team

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