Selected Work
Mizu
A companion app for people living with chronic kidney disease — a Class I medical device, in market since 2021, used by more than 10,000 patients.
Kidney disease doesn’t stop at the clinic door.
Chronic kidney disease is a progressive, lifelong condition. Patients manage it across stages — from early-stage CKD through dialysis and into transplant recovery — each with distinct clinical demands, dietary constraints, and monitoring requirements. Most of their time is spent outside any hospital.
Mizu was built to meet patients where they are: on iOS and Android, in the language of daily life. It is a regulated medical device (EU MDR 2017/745, Annex VIII Rule 11, Class I) — not a wellness app. That classification shapes every decision: how data is handled, how content is validated, how the system is architected. Getting it wrong has clinical consequences.
The product was developed in close collaboration with nephrologists, university hospitals, patients, and caregivers. The domain depth matters: the right food diary for a dialysis patient is not the same as one for a transplant recipient. Clinical accuracy and a usable interface are not in tension here — they are both required.
Founder · CTO
Carealytix Digital Health GmbH
Mizu is built by Carealytix Digital Health GmbH. The founder of Yam Labs serves as CTO at Carealytix — owning architecture, engineering direction, and technical delivery from the outset.
This is not a client engagement or a portfolio deliverable. It is what engineering leadership looks like in a regulated, real-world product: hiring and directing the engineering team, setting architectural standards, making the calls that determine whether the product ships — and whether it holds up once it does.
From system design to app store release, from clinical data flows to quality process documentation, the technical direction is owned by one person. That accountability is the point.
Behind the app is a platform that integrates with hospital systems at a depth most health apps never reach. It is built on a FHIR R4 backbone, event-driven across a dozen services, and held to ISO 13485 and 27001 processes — GDPR-compliant and EU-hosted. The hard engineering is in moving clinical data between hospitals and patients correctly, securely, and without losing a record.
Pulls patient records from hospital EHR systems over FHIR R4. The import pipeline is resumable and idempotent — checkpointed so a dropped connection picks up mid-stream — with a circuit breaker that tells a transient outage apart from bad source data.
Links an app identity to a hospital record without ever storing plaintext patient data. Envelope encryption (RSA-wrapped AES-GCM) makes the matching service a cryptographic mediator, not a PII store — with automatic key rotation, transparent to connected systems.
Normalises labs from heterogeneous hospital systems via LOINC and SNOMED, with per-analyte unit conversion across 50+ biomarkers — eGFR (CKD-EPI 2021), creatinine, potassium, immunosuppressant levels, dialysis adequacy (Kt/V).
Patient-recorded dialysis flows back to the hospital as standards-compliant FHIR — modelling the full clinical structure, treatment day to individual exchanges to fill/drain volumes, with correct SNOMED, LOINC, and German KBV coding.
A regulated app has to work without signal. A persistent action queue preserves order and survives restarts — with CI-enforced detection of schema changes that would otherwise corrupt queued medical data after an app update.
Append-only consent history (GDPR Art. 7), per-tenant data isolation at the storage layer, and end-to-end audit trails — compliance designed into the system, not bolted on before an audit.
Weight, blood pressure, eGFR, and kidney values tracked with structured data entry — designed for clinical hand-off and provider data sharing, not just personal awareness.
Nutrient data for thousands of foods, filtered for the values that matter in kidney disease: potassium, phosphorus, sodium, protein. Not a generic calorie counter — a tool built for the dietary constraints of CKD.
Session logging including ultrafiltration, weight gains, and session parameters. Built for patients on haemodialysis and peritoneal dialysis, with the specificity their condition requires.
A searchable, structured travel database covering dialysis centres worldwide — enabling patients to plan travel without interrupting treatment. A feature that exists nowhere in the generic app ecosystem.
Reminders and structured management built on the German IFA drug database — critical for transplant patients on complex immunosuppressant regimens and CKD patients managing comorbidities.
Educational content developed and validated with nephrologists and university hospitals. Not curated articles — clinician-reviewed material appropriate for a registered medical device.
More than 10,000 patients use Mizu daily across early-stage CKD, dialysis, and transplant — on iOS and Android, in German, from 2021 to now.
“Dein Begleiter im Leben mit Nierenkrankheit” — Your companion in life with kidney disease. The tagline is accurate. It ships, it is used, and it matters to the people using it.