Senior Software Developer/Architect | Java/Kotlin/Rust/DevOps

• Implemented a distributed financial ledger using event-based architecture
• Increased stability by rewriting a core integration for crypto trading and price feeds

Technologies used: Java 21, Spring, Spring Boot, Terraform, PostgreSQL, Kafka, Kubernetes, AWS

• Introduced a scalable statistics pipeline for similarity search
• Managed technical strategy in coordination with business needs as acting CTO

Technologies used: Kotlin, Spring Boot, Kafka, AWS, PostgreSQL, ElasticSearch, Kubernetes, Google Cloud

Focused on deepening expertise in blockchain development, smart contracts, and decentralized protocols.

Technologies used: Solidity, Ethereum, Cryptography, ReactJS, TypeScript, Foundry

Description:

Migrating the existing solution from a monolith to an event-driven architecture basedon Kafka. The solution extracts data from ServiceNow and links it together withitems regarding the same logical entity. Those logical entities form deployment unitswhich can be moved around on available ServiceNow instances. The ServiceNowinstances are labelled and form stages in a CI/CD process.

Responsibilities:

• Facilitated workshops about event-driven architecture and Kafka
• Guided the engineering team in creating a more scalable architecture to eventuallysupersede their monolith
• Implemented a prototype of a Kafka-based data pipeline reading from ServiceNowand producing a graph-based collection of business items

Achievements:

• Rolled out a prototype to their test environment, reducing latency for item ingestionand processing from 24 hours to near real time
• Demonstrated concepts and best-practices for future services

Languages: Java, Protobuf
Datastores: Kafka, PostgreSQL
Frameworks: Spring/Spring Boot, Kafka Streams, Kubernetes
Concepts: Event Driven Architecture
Cloud: Amazon Web Services EKS (Elastic Kubernetes Service)
Tools: ArgoCD, Jenkins, Maven, Grafana, Prometheus, AlertManager

Description 

Extending a trading platform with various features. One major project was scalingtheir quote stream which handles price data from external provider. As more productswere introduced and their existing provider license ended, their existing architecturecould not handle the load of the new external provider. Another project was aboutintroducing infrastructure-as-code for core-team based on Terraform modules, makingtheir whole cloud-infrastructure declarative

Responsibilities

• Introduced of infrastructure-as-code for the core teams to ensure traceability ofchanges
• Researched on using GraalVM (a polyglot runtime with Ahead-of-Time capabilities)for microservices
• Hands-on cross-team feature development
• Defined architectural constraints and extension points with ADRs (ArchitecturalDecision Records)
• Managed the core team

Achievements

• Scaled the existing quote stream components from 1-per-second to sub-secondprocessing
• Reduced startup time for their microservices from 60+ to a 5 seconds on average
• Carried out the promotion of a team member

Languages: Java, Kotlin, Protobuf, Terraform
Datastores: Kafka, RabbitMQ, PostgreSQL
Frameworks: Spring/Spring Boot, Kubernetes, GraalVM
Concepts: Event Driven Architecture, CQRS (Command-Query Responsibility Segregation)
Cloud :Google Cloud Platform (Networking, GKE (Google Kubernetes Engine), ComputeEngine, Buckets)
Tools: GitHub Workflows, Maven, Grafana, Prometheus, AlertManager

Description

Extending a trading platform with various features. Leading a team of engineersaround their career development, goals and growth in the company. The companyuses CQRS (Command-Query Response Segregation) excessively, maintaining itsown framework library in Java. Extension of the framework with business processmanagement layer

Responsibilities

• Led a team (two sub-teams) of eight software engineers to foster their professionalgrowth
• Designed a system for deferred execution of stock orders
• Extended the in-house CQRS library to support modelling business processes
• Feature development to extend the core platform

Achievements

• Achieved a 100% retention rate during my time as team-lead and facilitated the promotion of a team member
• Seamlessly rolled out deferred execution stock orders, processing over 5000 ordersdaily without any major operational disruptions
• Significantly reduced development time of two microservices by using the businessprocess abstraction
• Defined and setup a seamless on-call rotation with clear separation of responsibilitieson alerts among two sub-teams

Languages: Java, Kotlin, Protobuf, Python
Datastores: Kafka, RabbitMQ, PostgreSQL
Frameworks: Spring/Spring Boot, Kubernetes
Concepts: Event Driven Architecture, CQRS
Cloud: Google Cloud (Networking, GKE, GCP, Buckets)
​​​​​​​Tools: GoCD, Maven, Grafana, Prometheus, AlertManager2/4

Description:

Greenfield development of a trading platform. The platform executes stock ordersreceived by the end-user through the middleware. Orders are validated and trackedthroughout their lifecycle. Required cash and assets are reserved and exchangedafter the order executed. A product catalog and quotes are maintained to allow theend-user to choose which stock to buy/sell at which price.

Responsibiliites

• Implemented an order management system in a team of two from scratch
• Implemented a core product catalog which is automatically synced throughout allmicroservices
• Implemented a data pipeline providing quotes for services who need price tags
• Defined and managed all infrastructure needed for testing, operations and monitoring(we build it, we run it)
• Defined and implemented CI/CD and integration tests

Achievements

• Go-live of the trading platform (order management, quotes, product catalog) withno delay
• Enabled an efficient way for operations to do product updates across the services
• ​​​​​​​Setup a green field project around observability, CI/CD and cloud infrastructure

Languages: Java, Protobuf, Shell Scripting, Python
Datastores: Kafka, RabbitMQ, PostgreSQL
Frameworks: Spring/Spring Boot, Kubernetes
Concepts: Event Driven Architecture, CQRS
Cloud: Google Cloud (Networking, GKE, GCP, Buckets)
​​​​​​​Tools: GoCD, Maven, Grafana, Prometheus, AlertManager

Description

Adding event-driven workflow processing to an existing job-scheduling solution usingApache Flink. Extending an analytics software with various chart types and filtering features.

Responsibilities

• Feature development and system design
• Reduced technical debt in the web interface

Languages: Java, Shell Scripting, Cobol
Datastores: Kafka, PostgreSQL
Frameworks: Spring Boot, Kubernetes, Vaadin, Apache Flink, Cucumber

Description

The presentation management tool is a web-interface which allows importing imagesof various file types. These images can be combined together representing slidesin presentations. The presentations can be show-cased in the tool directly. Several transition animations are possible. A monolith architecture serves as a backend forstoring slides and metadata

Languages: Java
Datastores: MariaDB
Frameworks: Spring Boot