09/07/2026 updated
100 % available
Senior Backend Engineer / Softwarearchitekt · Java, Spring Boot, PostgreSQL, Kubernetes · Remote
Tallinn, Estonia
Germany +10
Tallinna Majanduskool, 1996-1999info: Germany, Austria, Switzerland, United Kingdom, Belgium, Denmark, Estonia, Finland, Netherlands, Norway, Sweden
About me
Senior Backend Engineer / Softwarearchitekt, 29 Jahre Erfahrung, remote aus Estland (EU). Arbeitssprache Englisch. Java, Spring Boot, PostgreSQL, Kubernetes; identity (OAuth2/OIDC), multi-tenancy, regulated data, HL7 FHIR. Founder of JenguCare; its open-source store: github.com/jengu-net/dbo
OAuth 2.0GitOpsISO 27001Java (Programming Language)Continuous IntegrationLinuxPostgreSQLOracle DatabasesScrum MethodologySoftware ArchitectureOpenid ConnectPL-SQLSQL DatabasesCloud Platform SystemSpring Boot
Java and Spring Backend Development
Nearly three decades of Java development experience since 1997, including Spring, OSGi, SQL, and PL/SQL. Extensive background building scalable, component-oriented backend services for national e-services, telecom, identity platforms, and healthcare systems.
Kubernetes and Cloud Platform Engineering
Deep expertise in Kubernetes-based cloud architecture, CI/CD pipelines, and deployment infrastructure. Hands-on experience running multi-tenant SaaS platforms on Kubernetes, including GitOps workflows from edge clusters to EU cloud environments.
Identity and Security Engineering
Comprehensive knowledge of OAuth2, OpenID Connect, IAM, ISO 27001, and GDPR. Practical experience implementing single sign-on for national grid operators and tax authorities, as well as leading ISO 27001 certification processes from ISMS to audit readiness.
PostgreSQL and Data Engineering
Strong proficiency in PostgreSQL and Oracle, including encryption at rest, audit trails, and multi-tenant database architectures where each tenant operates as its own isolated database instance.
HL7 FHIR and Healthcare Domain
Practical production experience with HL7 FHIR R4/R5 as a data model for clinical processes, including SMART on FHIR and LLM-driven workflows in a regulated healthcare environment.
Multi-Tenant SaaS Architecture
Design and implementation of multi-tenant SaaS platforms with durable workflows, device integration, and real-time data ingestion, including tenant configuration managed via GitOps.
Laboratory and Device Integration
Experience integrating clinical and laboratory analysers and bridge devices with real-time ingestion and anomaly detection, as well as owning data flows and system design for laboratory information systems.
OSGi Runtime and Open-Source Development
Expertise in OSGi-based runtime systems, including building and open-sourcing DBO, a regulated-data store over PostgreSQL with per-tenant isolation, encrypted payloads, audited reads, and integration-tested containers.
Scalable Web Services for Identity and Access Management
Design and implementation of highly scalable web services for identity and access management, with experience at Twilio and in national e-government contexts.
Nearly three decades of Java development experience since 1997, including Spring, OSGi, SQL, and PL/SQL. Extensive background building scalable, component-oriented backend services for national e-services, telecom, identity platforms, and healthcare systems.
Kubernetes and Cloud Platform Engineering
Deep expertise in Kubernetes-based cloud architecture, CI/CD pipelines, and deployment infrastructure. Hands-on experience running multi-tenant SaaS platforms on Kubernetes, including GitOps workflows from edge clusters to EU cloud environments.
Identity and Security Engineering
Comprehensive knowledge of OAuth2, OpenID Connect, IAM, ISO 27001, and GDPR. Practical experience implementing single sign-on for national grid operators and tax authorities, as well as leading ISO 27001 certification processes from ISMS to audit readiness.
PostgreSQL and Data Engineering
Strong proficiency in PostgreSQL and Oracle, including encryption at rest, audit trails, and multi-tenant database architectures where each tenant operates as its own isolated database instance.
HL7 FHIR and Healthcare Domain
Practical production experience with HL7 FHIR R4/R5 as a data model for clinical processes, including SMART on FHIR and LLM-driven workflows in a regulated healthcare environment.
Multi-Tenant SaaS Architecture
Design and implementation of multi-tenant SaaS platforms with durable workflows, device integration, and real-time data ingestion, including tenant configuration managed via GitOps.
Laboratory and Device Integration
Experience integrating clinical and laboratory analysers and bridge devices with real-time ingestion and anomaly detection, as well as owning data flows and system design for laboratory information systems.
OSGi Runtime and Open-Source Development
Expertise in OSGi-based runtime systems, including building and open-sourcing DBO, a regulated-data store over PostgreSQL with per-tenant isolation, encrypted payloads, audited reads, and integration-tested containers.
Scalable Web Services for Identity and Access Management
Design and implementation of highly scalable web services for identity and access management, with experience at Twilio and in national e-government contexts.
Experience
Professional experience10+ years
Freelancer since2007
Languages
EnglishFluent
Project history
Founded and built a multi-tenant healthcare SaaS platform using Java and Spring Boot on Kubernetes, with FHIR as the data model, durable workflows for clinical processes, and GitOps from a Raspberry Pi edge cluster to EU cloud. Modules include laboratory integration, an AI visit assistant, national insurance integration, and Estonian terminology packages. Open-sourced the storage backbone DBO, an OSGi runtime over PostgreSQL with per-tenant isolation, encrypted payloads, audited reads, and integration-tested containers.
Owned system design and integrations with clinical and laboratory analysers, managed data flows, and built the development team and its practices. Led the company's ISO 27001 certification including information security management system, policies, and audit readiness. Responsible for HEDA and ESTER laboratory information systems.
Designed and implemented highly scalable web services for identity and access management.