08/24/2026 updated
100 % available
Hands-on Tech Lead & Software Architect | Java, Spring Boot, Microservices | Banking & Fintech
Zlonin, Czech Republic
Only remote
Bc. Financial Informatics, University of West BohemiaAbout me
Independent since 2010, with 15 years of enterprise Java across banking, insurance, wholesale retail and telco. I validate architecture by implementing it - I have never stopped writing code. Recent work: an SME lending origination platform and a core banking migration, both in production.
Java (Programming Language)Java ArchitecturesSpring FrameworkPostgreSQLSoftware ArchitectureRedisSystems IntegrationTechnical ManagementEvent-driven ArchitectureSpring CloudSpring BootBackendEvent Driven ArchitectureKubernetesApache Kafka
Hands-on tech lead and software architect. 15 years in enterprise Java, the last five in core banking and SME lending, with earlier work across insurance, consumer finance, wholesale retail and telco.
I design and I build, and the second part is how I validate the first: a design I have not implemented is a hypothesis. Most recently I spent nearly five years at one of the largest Czech banks as architect and technical lead on two production platforms - an SME lending origination platform for business clients, and a core banking migration platform that moved close to a million retail clients to a new digital core.
Backend & architecture: Java, Spring Boot, Spring Framework, Jakarta EE, JAX-RS, REST API design, microservices, Domain-Driven Design (DDD), CQRS, event sourcing, event-driven architecture, systems integration and orchestration.
Data & messaging: Apache Kafka, ActiveMQ Artemis, PostgreSQL, Redis, JPA/Hibernate, MapStruct.
Platform & tooling: Kubernetes, Docker, Git, Maven, CI/CD, JUnit, Mockito, Testcontainers, IntelliJ IDEA.
Leadership: technical leadership of delivery teams, architecture ownership, code review, mentoring developers from their first commercial commit to independent mid-level engineers.
AI-assisted delivery: AI coding tools are part of my daily workflow and measurably shorten the path from design to tested, production-ready code.
Domain: core banking, client migration, loan origination, SME lending, decisioning workflows, regulatory and audit requirements, high-integrity data processing.
Working through my own limited company (s.r.o.), available for fully remote engagements across Europe. Fluent English, based near Prague, CET.
Experience
Professional experience10+ years
Freelancer since2010
Languages
GermanBasic knowledgeEnglishFluentItalianBasic knowledgeCzechNative speaker
Project history
Third engagement with the bank, following earlier work in 2008-2011 and 2012-2013.
Architect and technical lead on two production platforms built on the bank's proprietary Spring Boot-based framework - microservices, DDD, CQRS, Kafka and Artemis messaging, PostgreSQL, Redis, Kubernetes.
SME LENDING ORIGINATION PLATFORM
- Architect and technical lead of one of five sub-teams delivering an origination platform for business loans.
- End-to-end product journey: application intake, decisioning workflow, external data and registry integrations, contracting.
- Designed and built to extend beyond SME to corporate lending; corporate scope in development at the time of handover.
- In production, processing loan applications for the bank's business clients.
- Mentored developers with no prior commercial experience into independent mid-level engineers.
CORE BANKING MIGRATION PLATFORM
- Co-owned the architecture as one of two peer architects and tech leads.
- Migrated close to a million retail clients from the legacy core banking system to a new digital core.
- Designed the integration orchestration layer spanning dozens of surrounding systems, with full auditability and reconciliation across migration waves.
- Live in production.
Took over an externally developed core insurance platform and restored the client's ability to build, deploy and evolve it in-house.
- The platform had been delivered by an external vendor on the vendor's own framework: Spring Boot services deployed as Docker Swarm containers, MongoDB as the primary data store with no relational database, ELK for observability. Despite the container topology, the application was effectively a single large service running in multiple instances and versions of itself.
- The handover transferred application source code and running test and production environments, but no build or delivery infrastructure.
- Reconstructed the entire build and deployment chain from source - determining how the container images were assembled and how releases reached the target environments - until the team could build, deploy and release independently. This took several months and unblocked all further development.
- Once delivery was restored, owned the architecture and led in-house development of the platform.
Stack: Java, Spring Boot, Lombok, MapStruct, MongoDB, Docker Swarm, ELK.
Cloud backend for a global IP intercom and access control product line - door and lift intercoms with audio and video, remotely managed from the cloud.
- Microservices on AWS running on Kubernetes, built with Spring Cloud and the Netflix OSS stack, PostgreSQL and Redis.
- Device-to-cloud integration at fleet scale: every unit in the field communicated with the platform, making device connectivity, state handling and firmware-facing contracts the core of the architecture.
- Worked across three disciplines - cloud backend, frontend and device firmware - so API contracts had to hold for both a web client and embedded hardware.
- Technical lead of one of several sub-teams of five to six developers.
- Built the platform's reactive services in Java.
Stack: Java, Spring Boot, Spring Cloud, Netflix OSS, reactive Java, PostgreSQL, Redis, Lombok, MapStruct, Kubernetes, AWS.