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Timo Külbel

Senior Fullstack Developer

Timo Külbel
Bremen, Germany

Experience

Jan 2025 - Present
1 year 1 month

Senior Fullstack Developer

  • Lead Developer / Tech Lead in a large banking group for the complete redevelopment of payment systems
  • Rework of payment processing in stream processing
  • Design and development of the stream processing for international payments based on Kafka and Kafka Streams
  • Development of various input formats for the business unit using Drools rules for dynamic adjustment of validation rules
  • Evaluation and comparison of different public cloud providers regarding available databases
  • Technologies & Tools: Java 21, Kotlin, Spring Boot, Kafka, Kubernetes, Azure, TDD, JEE, REST, Angular, Spark, Google Cloud, SCDF, PostgreSQL, Drools, Git, S3, MongoDB
May 2024 - Nov 2024
7 months

Senior Fullstack Developer

  • Development and maintenance of a claims application based on the Faktorzehn claims system with Java, Spring Boot and Vaadin
  • Development of business processes using Camunda
  • Development of asynchronous data interfaces to involved systems using Azure Service Bus
  • Development of Grafana dashboards for production monitoring
  • Role as Product Owner and Data Protection Officer
  • Team size: 12
  • Technologies & Tools: Java 17, Spring Boot, Vaadin, Azure, ArgoCD, Kubernetes, PostgreSQL, Camunda, Git, Faktorzehn, AzureServiceBus, Grafana, Octane
May 2023 - Dec 2023
8 months

Team Lead Data Migration

  • Technical Product Owner for data migration tickets
  • Supporting management, domain design and business API analysis with functional and technical architecture questions
  • Design of the data migration architecture for two applications
  • Development and maintenance of several backend tools for data migration using Spring Boot, Kotlin and Oracle
  • Lead Developer for a 12-member development team
  • Team size: 15
  • Technologies & Tools: Kotlin, Spring Boot, Oracle, Azure, Kotlin Exposed, Azure DevOps, Git, Jira
Nov 2022 - Jun 2024
1 year 8 months

Senior Backend Developer and Data Engineering

  • Development and maintenance of backend applications using Spring Boot, Spring WebFlux and Kotlin
  • Development of data pipelines using Spark and Scala
  • Optimization of analytical search queries and full-text searches
  • Development and maintenance of data workflows using ArgoCD
  • CI/CD using Azure DevOps
  • Team size: 6
  • Technologies & Tools: Kotlin, Spring Boot, Spring WebFlux, Azure, CosmosDB, Azure Search, ArgoCD, Databricks, Apache Spark, Scala, Azure DevOps, Git
May 2022 - Nov 2022
7 months

Senior Software Developer

  • Migration of a C++-based CORBA payment procedure for unemployment benefits (approx. €15 billion annual payout) to Java EE 7
  • Programming backend applications, microservices and REST services with Java EE 7 APIs (EJB, JPA, JAX-RS, CDI)
  • Applying complex build processes (Maven, Git, Stash, Jenkins)
  • Debugging, profiling, testing, integration and documentation of migrated software components
  • Team size: 14
  • Technologies & Tools: Java EE 7, EJB, JTA, JAXB, JAX-RS, JPA, CDI, Bean Validation, Interceptors, Managed Beans, Microservices, REST, Maven, Git, Jenkins, Mockito, Wiremock, Gatling
Mar 2021 - Jan 2022
11 months

Lead Developer Backend

  • Development of the backend component for a social network of a sustainable phone manufacturer
  • Integration of the system with Keycloak
  • Development of the back office GUI of the social network
  • Planning the architecture for extending and further developing the application
  • Team size: 12
  • Technologies & Tools: JHipster, Kotlin, Spring Boot, Angular, Keycloak, HATEOAS
Nov 2019 - Mar 2022
2 years 5 months

Fullstack Developer and Product Owner

  • Building a fully digital application process for a leasing company and integrating it into marketplaces
  • Maintenance and further development of the digital application process
  • Designing and developing a leasing and used car offering platform
  • Development of various interfaces to external and internal partners
  • Frontend development of the leasing configuration process
  • Product Owner for used car leasing
  • Team size: 15
  • Technologies & Tools: Kotlin, Kubernetes, Azure, MongoDB (Cosmos), React, NATS, Redis, Camunda
May 2019 - Nov 2019
7 months

Technical Team Lead

  • Designing, developing, and operating a pricing microservice
  • Maintaining user stories in Jira
  • Developing the backend pricing logic
  • Developing caching strategies
  • Team size: 4
  • Technologies & Tools: Java, Kubernetes, Azure, MongoDB, Redis
Oct 2018 - Apr 2019
7 months

Senior Software Developer

  • Further development of a notification component for customer emails in a high-load scenario
  • New development of a push notification component
  • Performing DevOps tasks: CI/CD, code, version, and release management
  • Team size: 8
  • Technologies & Tools: Java, OpenShift, Google Firebase, JMS, ActiveMQ, Oracle
Apr 2018 - Sep 2018
6 months

Senior Software Developer

  • New development of a package shop finder using microservices
  • Creating automated load tests for the package shop finder with Gatling
  • DevOps tasks in the context of OpenShift
  • Development using Test Driven Development
  • Team size: 3
  • Technologies & Tools: Kotlin, OpenShift, Spring Boot, MongoDB, Grafana, Gatling
Jan 2018 - Present
8 years 1 month

Freelance Developer

  • Developed various management tools for mid-sized companies (e.g., backend for Onlinemassage booking platform, ERP for a plumbing company, inventory management system for a moving company)
  • Developed an ERP system for multichannel delivery for DIY and textile retail with API connections to Shopify, Etsy, and Amazon, as well as email integration via SendGrid
  • Technologies & Tools: JHipster, Kotlin, Spring Boot, Angular, Keycloak, PostgreSQL, Neo4J, DuckDB, GraphQL
Apr 2013 - Mar 2018
5 years

Lead Developer and Java Architect

  • Customized and enhanced fleet management software to support the establishment of a fleet management service company
  • Deputy head of development at the software service provider
  • Technical project manager for the client
  • Lead developer of a sprint team
  • Security and data protection officer
  • Responsible for interface development (SOAP, REST), reporting, and business documents
  • Further development, bug fixing, and full-service cost calculations
  • Designed the billing concept for travel management
  • Team size: 7
  • Technologies & Tools: Java, Struts, Hibernate, Oracle, BIRT, SOAP, REST
Jun 2011 - Mar 2013
1 year 10 months

Senior Developer

  • Customized and extended claims management software for auto B2B insurance
  • Technical project manager for the client
  • Responsible for interface development (SOAP, REST)
  • Team size: 3
  • Technologies & Tools: Java, Struts, Hibernate, Oracle, BIRT, SOAP
Jan 2010 - May 2011
1 year 5 months

Senior Developer

  • International rollout of a fleet management solution in 26 countries
  • Developed various invoice importers and country-specific adjustments for invoice processing
  • Created CI/CD build processes
  • Developed using test-driven development
  • Team size: 6
  • Technologies & Tools: Java, Struts, Hibernate, Oracle, BIRT
Jul 2009 - Dec 2009
6 months

Java Developer

  • Developed PDF reports using iText
  • Test-driven development
  • Architecture planning for application extension
  • Internationalization and design of the PDF statements
  • Team size: 2
  • Technologies & Tools: Java, DB2, iText
Jul 2007 - Jun 2009
2 years

Java Developer

  • Development of web crawlers in credit reporting, including press crawlers
  • Operation and maintenance of imprint and company monitoring crawlers
  • Development of a frontend for evaluating results by research staff
  • Integration of crawler execution into UC4
  • Team size: 2
  • Technologies & Tools: Java, DB2, JSF, Lucene, UC4
Nov 2003 - Jun 2007
3 years 8 months

Software Architect

  • Responsible for the development and architecture of an ROLAP engine for analytical database marketing (target group segmentation, response analysis)
  • Coordination of test management with the client
  • Support in defining target groups within the ROLAP engine
  • Architecture planning for application expansion
  • Test Driven Development
  • Team size: 6
  • Technologies & Tools: Java, Struts, Hibernate, AspectJ, Oracle

Skills

Top Skills

  • Java (22 Years)
  • Kotlin (7 Years)
  • Spring Boot (8 Years)
  • Kubernetes (4 Years)
  • Azure (6 Years)
  • Tdd (10 Years)
  • Jee (10 Years)
  • Rest (7 Years)
  • Angular (5 Years)
  • Spark (2 Years)

Industry Experience

  • Automotive (12 Years)
  • Leasing (5 Years)
  • Insurance (5 Years)
  • Credit Bureau (2 Years)
  • E-commerce (4 Years)
  • Shipping Logistics (1 Year)

Non-dev Experience

  • Tech Lead (2 Years)
  • Technical Project Management (5 Years)
  • Product Owner (1 Year)
  • Data Protection Officer (1 Year)

Programming Languages

  • Java (=Excellent)
  • Kotlin (=Excellent)
  • Typescript (=Excellent)
  • Scala (=Medium)
  • Javascript (=Excellent)
  • Rust (=Basic)
  • Oracle (=Good)
  • Sql (=Excellent)
  • Postgres (=Good)
  • Mongodb (=Excellent)
  • Redis (=Medium)
  • Cosmosdb (=Medium)
  • Neo4j (=Basic)
  • Duckdb (=Excellent)

Databases

  • Oracle – Expert Knowledge
  • Postgresql – Expert Knowledge
  • Mysql – Basic Knowledge
  • Mssql – Advanced Knowledge
  • Mongodb – Expert Knowledge
  • Arango Db – Basic Knowledge
  • Elasticsearch – Advanced Knowledge
  • Neo4j – Advanced Knowledge
  • Liquibase – Expert Knowledge
  • Flyway – Expert Knowledge

Frameworks

  • Angular – Advanced Knowledge
  • React – Advanced Knowledge
  • Spring Boot – Expert Knowledge
  • Java Ee (Jakarta Ee) – Expert Knowledge
  • Jax-ws – Expert Knowledge
  • Bootstrap – Basic Knowledge
  • Apache Camel – Basic Knowledge
  • Apache Wicket – Basic Knowledge
  • Google Web Toolkit (Bootstrap / Platform / Ext / Rpc) – Advanced Knowledge
  • Hibernate – Expert Knowledge
  • Struts – Expert Knowledge
  • Flutter – Basic Knowledge

Libraries

  • Rxjs – Basic Knowledge
  • Material-ui – Basic Knowledge
  • Jquery – Basic Knowledge
  • Spring Data – Expert Knowledge

Interfaces

  • Rest – Expert Knowledge
  • Graphql – Expert Knowledge
  • Grpc – Basic Knowledge
  • Soap – Expert Knowledge
  • Openapi/swagger – Expert Knowledge

Cloud

  • Aws – Basic Knowledge
  • Azure – Expert Knowledge
  • Openshift – Advanced Knowledge
  • Kubernetes – Expert Knowledge

Testing

  • Selenium – Basic Knowledge
  • Jest – Basic Knowledge
  • Junit – Expert Knowledge
  • Mockito – Expert Knowledge
  • Wiremock – Expert Knowledge
  • Postman – Expert Knowledge
  • Soapui – Expert Knowledge
  • Apache Jmeter – Basic Knowledge

Messaging

  • Apache Kafka – Basic Knowledge
  • Nats – Expert Knowledge
  • Activemq – Advanced Knowledge
  • Redis – Expert Knowledge
  • Jms – Advanced Knowledge

Operating Systems

  • Windows – Expert Knowledge
  • Linux – Advanced Knowledge
  • Macos – Expert Knowledge

Project Methods

  • Scrum – Expert Knowledge
  • Kanban – Expert Knowledge
  • Waterfall Model – Expert Knowledge
  • V-model – Expert Knowledge
  • Spiral Model – Basic Knowledge

Tools

  • Git – Expert Knowledge
  • Gitlab – Advanced Knowledge
  • Github – Basic Knowledge
  • Bitbucket – Basic Knowledge
  • Apache Subversion – Advanced Knowledge
  • Jira – Expert Knowledge
  • Confluence – Expert Knowledge
  • Trello – Expert Knowledge
  • Sonarqube – Basic Knowledge
  • Docker – Advanced Knowledge
  • Jenkins – Advanced Knowledge
  • Apache Maven – Expert Knowledge
  • Gradle – Advanced Knowledge
  • Terraform – Basic Knowledge
  • Glassfish – Basic Knowledge
  • Oracle Sql Developer – Expert Knowledge
  • Jpa – Expert Knowledge
  • Jsp – Expert Knowledge
  • Keycloak – Advanced Knowledge

Platforms

  • Camunda – Expert Knowledge
  • Cadence – Advanced Knowledge
  • Apache Kafka – Basic Knowledge

Concepts

  • Code Review – Expert Knowledge
  • Pair Programming – Advanced Knowledge
  • Tdd – Test Driven Development – Expert Knowledge
  • Clean Code – Expert Knowledge
  • Solid – Expert Knowledge
  • Bdd – Behavior-driven Development – Advanced Knowledge
  • Responsive Design – Basic Knowledge
  • Component-oriented Web Development – Expert Knowledge
  • Redux – Basic Knowledge

Architecture Patterns

  • Domain-driven Design (Ddd) – Advanced Knowledge
  • Microservices – Expert Knowledge
  • Mvc (Model-view-controller) – Expert Knowledge
  • Mvvm (Model-view-viewmodel) – Basic Knowledge

Ides

  • Intellij – Expert Knowledge
  • Vscode – Advanced Knowledge
  • Eclipse – Expert Knowledge

Others

  • Spring Eco – Expert Knowledge
  • Ci/cd Pipelines – Expert Knowledge
  • Apache Tomcat – Expert Knowledge
  • Apache Spark – Expert Knowledge
  • Orm Modelling With Hibernate – Expert Knowledge
  • Java Servlet – Expert Knowledge
  • Websphere Application Server – Basic Knowledge
  • Extreme Programming (Xp) – Basic Knowledge
  • Oauth 2.0 / Openid Connect – Advanced Knowledge

Languages

German
Native
English
Advanced
Spanish
Elementary

Education

Lorem ipsum dolor sit amet

Diploma in Business Informatics · Business Informatics

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