Senior Staff Software Engineer at Kontakt.io · Krakow

About Kontakt.io

http://Kontakt.io is building the platform that care operations run on.

We reduce waste, cut costs, and improve throughput in hospitals by automating and orchestrating clinical workflows. Using AI, real-time location data (RTLS), and deep EHR integration, our platform enables care teams to operate with real-time intelligence and financial discipline.

Trusted by leading U.S. health systems including HCA, Sutter Health, AdventHealth, Trinity Health, and the U.S. Department of Veterans Affairs — and backed by Goldman Sachs — we are scaling rapidly toward the next phase of durable, disciplined hypergrowth.

http://Kontakt.io is the leading IoT platform for real-time location and telemetry in healthcare and enterprise. Our 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 team is the connective tissue of this platform. We own the full data ingress pipeline — from third-party devices (Cisco, Aruba, and beyond) to our internal Kafka backbone — and we own egress: streaming enriched location and telemetry data out to downstream systems, external APIs, and partner platforms. We are rebuilding this domain the right way: event-driven, observable, documented, and built to scale.

We need a technical anchor — someone senior enough to raise the bar, pragmatic enough to ship, and confident enough to drive alignment across engineering and product.

What you will work on:

Data ingress & device integration

Own the pipeline that brings external device data into the http://Kontakt.io platform. Build and maintain robust integrations with Cisco Spaces, Aruba, and similar third-party infrastructure. High-volume BLE telemetry, Kafka Streams, gRPC — multi-tenant SaaS where both correctness and latency matter.

Data egress & external integrations

Build and evolve the egress layer that streams enriched location and event data to partner systems and customer-facing APIs — real-time position feeds, alarm forwarding, standards-compliant adapters. You own how the outside world consumes http://Kontakt.io data.

Architecture & technical leadership

You will drive the architectural evolution: what to rewrite, what to stabilize, and how to sequence it without breaking production. You establish the engineering standards — documentation, testing with Testcontainers, observability with Prometheus/Grafana — and you hold the team to them.

Cross-team ownership

Work directly with product stakeholders to translate business requirements into engineering decisions. When scope is unclear, you clarify it. When dependencies block the team, you resolve them.

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

Private healthcare, Multisport card, and standard benefits package

Hybrid from Kraków office - at least 2 days in the office

A real technical challenge — not a maintenance role on a stable codebase