Mario Ellebrecht
Freelance Developer
Experience
Jan 2022 - Present
2 years 7 months Ulm, Germany
Freelance Developer
Software-Hersteller
- Java 17 backend development with Spring Boot as lead developer
- Redesign of a customer-specific production control system
- Creation of a customizable standard product based on a newly proposed technology stack (Angular, GraphQL, Neo4j)
- BPMN support with bpmn.io and Flowable
- Realignment of the agile development process
- Leading open space workshops on technology topics
- Java 17, Spring Boot, GraphQL, Netflix DGS, Neo4j, Spring Data Neo4j, Liquibase Neo4j, Prometheus, Grafana, Docker, Kubernetes, Scrum/Kanban, Azure DevOps
Jan 2021 - Dec 2022
1 year Mannheim, Germany
Freelance Developer
Roche Diagnostics
- Java 11/Kotlin full-stack development with ZK OSS and Spring Boot
- Data ingest and persistence with Kafka, ActiveMQ, MongoDB
- Domain model with domain-driven design (DDD)
- Event-driven architecture, event sourcing, CQRS
- Roadmap for GraphQL migration
- Kotlin, Ktor, Java 11, Spring, REST, ActiveMQ, Redis, MongoDB, Kafka, AWS, Docker, Kubernetes, Bitbucket, Selenium, Scrum, LS
Jan 2020 - Dec 2022
2 years Cologne, Germany
Freelance Developer
talentsconnect AG
- Kotlin backend development of GraphQL/REST microservices
- Persistence and graph processing with Neo4j/ONgDB
- Integration of a range of SSO services via OAuth2/SAML
- Kotlin, Ktor, Spek, Neo4j/ONgDB, GraphQL, Docker Swarm, AWS, Weblate, ELK, Prometheus, Grafana, Sentry, Locust, Scrum, arc42
Jan 2019 - Dec 2020
2 years Berlin, Germany
Freelance Developer
Deutsche Bahn Station&Service
- Java 11 backend development of various REST microservices
- Central platform for controlling distributed embedded devices
- Event-driven architecture with AMQP and Apache Kafka
- Java 11, Spring Boot, REST/HATEOAS, OpenAPI, RabbitMQ, Avro, Protocol Buffers, Kafka, Flyway, PostgreSQL, MongoDB, Redis, AWS, Acapela TTS, Kubernetes, Helm, GitLab, Selenium, Scrum/SAFe
Jan 2016 - Dec 2020
3 years Hanover, Germany
Freelance Developer
Volkswagen Nutzfahrzeuge
- Java 11 backend development with Spring Boot, Microsoft Azure
- New development of a GraphQL API as an aggregator for numerous REST microservices for VW ConnectFleet fleet management
- Later conversion to Spring WebFlux and reactive streams
- Domain model and GraphQL schema elaboration
- Coordination of technical collaboration with VW, Audi, Porsche/MHP
- Java 11, Spring Boot, GraphQL Java, GraphQL SPQR, Kafka, Graal, Docker, Kubernetes, Helm, Azure, AWS, JIRA, Confluence, GitLab
Jan 2016 - Dec 2017
1 year Berlin, Germany
Freelance Developer
SearchInk/omni:us
- Java/Python backend development and software architecture
- Document search and classification with Apache Lucene
- Onboarding and support tasks for machine learning
- Natural language processing (Word2Vec, OCR, HTR)
- Python machine learning (Random Forest, SVM, k-means etc.)
- Deep learning (CNN, RNN) with TensorFlow, Keras and Torch
- Java SE 8, Python, Spring Boot, REST, Gensim, Google Cloud (GCP)
Jan 2015 - Dec 2017
2 years Berlin, Germany
Freelance Developer
Telefonica Next/Live Reply
- Java/Scala backend development and software architecture
- New development of an IoT platform in the B2B2C segment
- API client with dynamic integration of Swagger/OpenAPI in Go
- IoT apps with BTLE, 2G and LPWAN (Sigfox, NB-IoT) connectivity
- Java SE 8, Go 1.8, Scala, Akka, Node.js, REST, CQRS, MQTT, self-contained systems, AWS, CircleCI, GitHub, Alexa, Raspberry Pi
Jan 2015 - Dec 2016
1 year Berlin, Germany
Freelance Developer
E-POST Development GmbH
- Java/Scala backend development for a migration project
- Redesign with scalable REST microservice architecture
- Java SE/EE, Vert.x, Scala, Akka, Cassandra, OAuth, HATEOAS, CQRS
Jan 2015 - Dec 2016
1 year Stuttgart, Germany
Freelance Developer
Sulzer GmbH
- Java/Scala backend development and software architecture
- Java SE/EE, Play, Akka, Scala, REST microservices, JSON, OpenAPI
Jan 2015 - Dec 2015
1 year Berlin, Germany
Freelance Developer
AVM GmbH
- New development of a highly available, scalable REST API for encrypted messages between FRITZ!Box and mobile app
- Java backend development and architecture
- Java SE, Vert.x, MySQL, Redis, Dropwizard, JOSE/JWE, Android
Jan 2015 - Dec 2015
1 year Düsseldorf, Germany
Freelance Developer
Metro Systems
- Java backend development for global web service portfolio
- Java EE, Spring/Batch, REST, Groovy, WildFly, Jersey, PostgreSQL
Jan 2015 - Dec 2015
1 year Münster, Germany
Freelance Developer
viadee Unternehmensberatung
- Modernization of a large distributed custom ERP system
- Java SE/EE, EJB, web services, Spring, Hibernate, ESB, EAI, Linux
Jan 2014 - Dec 2015
1 year Frankfurt, Germany
Freelance Developer
Nokia HERE Global B.V.
- Java backend development and architecture
- Scoring, geo-transformation, remoting, search index with Lucene
- Java SE/EE, JSON, REST, Lucene, Hadoop, Kryo, GeoTools, JTS, Elasticsearch, AWS (EC2, S3, EBS, EMR, IAM), RabbitMQ, Linux
Jan 2013 - Dec 2014
1 year Frankfurt am Main, Germany
Freelance Developer
Navteq B.V.
- Java backend development and architecture
- RDF map data acquisition and transformation for geocoding
- Log management, test frameworks, custom Eclipse distribution
- Java SE/EE, JSON, REST, Spring/Batch, Lucene, JTS, Linux, Scrum
Jan 2010 - Dec 2013
2 years Stuttgart, Germany
Freelance Developer/Architect
Nawio GmbH
- Embedded Gentoo Linux on DO160-certified avionics platform
- Complete new product development including OS, GUI, network
- Majority of code authored, including 3D, GPS, terrain, geography
- Java SE, GeoTools, jMonkeyEngine, OpenStreetMap, REST, MQTT
Jan 2009 - Dec 2010
1 year Düsseldorf, Germany
Freelance Developer
Vodafone D2
- Assessment of a large ATG-based shop system
- Technical concept and implementation of multiple Wicket apps
Jan 2009 - Dec 2009
1 year Heidelberg, Germany
Freelance Consultant
HMI GmbH
- Architecture, project management and organizational consulting
- Speech understanding system based on standard recognizers
- Contribution to competitive presentation at Daimler AG, Stuttgart
- Nuance VoCon, VoiceXML, J2SE, MySQL
Jan 2009 - Dec 2009
1 year Düsseldorf, Germany
Freelance Consultant
Vodafone D2
- Reengineering of a large application landscape for internal and external web-based GIS applications
- Detailed specification for application migration
Jan 2009 - Dec 2009
1 year Bonn, Germany
Freelance Consultant
mind Business Consultants
- Consulting in a turnaround project for Deutsche Telekom Value-added Services Center on multiple speaker identification systems
- Business cases, workshops, architecture, concept creation
- Nuance Recognizer/Verifier, VoiceXML, J2EE
Jan 2008 - Dec 2009
2 years Berlin, Germany
Freelance Developer
Qiro GmbH
- Implementation of a J2ME app for a location-based community with server-side positioning and REST clients for Google Local Search, Google Maps and HRS
- Java ME, REST, JSON, Google APIs
Jan 2008 - Dec 2009
1 year Frankfurt, Germany
Freelance Consultant
Deutsche Bahn Systel
- Technical architecture, tender process and vendor selection for implementing a voice portal in a large, distributed VoIP-based call center infrastructure
- VoiceXML, VoIP, SAP BCM/Wicom, Cisco
Jan 2008 - Dec 2009
1 year Hamburg, Germany
Freelance Developer
Navigon / Skobbler
- Architecture reengineering and system specification of the navigation app
- Redesign of the Skobbler app
- Cross-platform design for J2ME, Symbian, BlackBerry, Android
- Coaching developers in Germany and Cluj/Romania
Jan 2007 - Dec 2008
1 year Cologne, Germany
Freelance Developer
CAP GmbH
- Implementation and rollout of the redesign of a voice application for the HappyDigits loyalty program customer portal based on VoiceObjects and an ASP-hosted VoiceXML platform
Jan 2007 - Dec 2008
1 year Berlin, Germany
Freelance Developer
Jamba GmbH
- Technical specification and implementation of a globally deployed infrastructure for mobile portals covering almost all XHTML/WML/J2ME-capable devices
- Integration of UAProf, WURFL, J2MEPolish device databases
Jan 2005 - Dec 2008
2 years Düsseldorf, Germany
Freelance Developer
upside GmbH
- Technical concept and implementation of a web-based marketing information system with PHP for T-Mobile International
- Architecture and software development process consulting
Jan 2005 - Dec 2006
1 year London, United Kingdom
Freelance Consultant
Ostrich Media Ltd.
- Technical specification, vendor selection, project/partner management for IVR of a high-volume interactive TV format
- Mission-critical application delivered within six weeks in cooperation with network operator Affiniti
- High-volume call testing with external VoIP call generator
Jan 2005 - Dec 2006
1 year Bad Homburg, Germany
Freelance Consultant
Strateco GmbH
- Preparation and execution of a workshop on technical and marketing roadmap for speaker identification at T-Online
Jan 2005 - Dec 2006
1 year Dresden, Germany
Freelance Consultant
T-Systems MMS GmbH
- Consulting for Senior EVP Value-Added Services at T-Com
- Comprehensive review of voice platform portfolio
- Recommendations in the form of a roadmap
Jan 2004 - Dec 2005
1 year Bad Homburg, Germany
Freelance Consultant
Strateco GmbH
- Technical consulting and strategy for building an online development environment for VoiceXML applications in the VOICE community
- Training, technical article creation, developer workshops
Jan 2004 - Dec 2005
1 year Cologne, Germany
Freelance Developer
VoiceObjects AG
- Development of a voice application for automated technical customer service in the T-Com call center based on VoiceObjects and Genesys VoiceXML ASP platform
- Tuning to optimize recognition rates and latency
Jan 2004 - Dec 2006
3 years Hamburg, Germany
Freelance Developer
Navigon GmbH
- Software architecture, development and marketing support to build a navigation system for Java-capable mobile phones
- Process design and lead development for GUI framework, client/server protocol, map matching algorithm, testing and profiling tools, J2ME Polish
- Roadmap for future platforms and APIs
- J2ME, J2ME Polish, Navteq, TeleAtlas, OpenStreetMap
Jan 2004 - Dec 2004
1 year Munich, Germany
Freelance Consultant
Euvia Media AG
- Technical consulting and strategy for creating various CRM applications to support business processes in the mass-call IVR system for interactive TV formats
Jan 2004 - Dec 2004
1 year Düsseldorf, Germany
Freelance Developer
VoiceObjects AG und net mobile AG
- Planning and execution of tuning measures for HP OpenCall VoiceXML platform, Nuance Recognizer, VoiceObjects server and Cisco SIP/H.323 gateway
Jan 2003 - Dec 2004
2 years Düsseldorf, Germany
Freelance Developer
upside GmbH
- Technical concept and development to build an affiliate webshop for T-Com’s DSL, ISDN and online offers with PHP
Jan 2003 - Dec 2004
1 year Hamburg, Germany
Freelance Consultant
HypoVereinsbank AG
- Project planning, concept, preparation and management of the tender at HVB Direkt GmbH for telebanking innovation using voice applications for transfers and other use cases
Jan 2003 - Dec 2004
1 year Düsseldorf, Germany
Freelance Consultant
zefa visual media GmbH
- Project management, analysis, design, developer mentoring as trainer and coach for creating web applications for the photo licensing order process of the third largest photo agency
Jan 2002 - Present
23 years 7 months Berlin, Germany
Freelance Developer and Consultant
Jan 2002 - Dec 2004
2 years Berlin, Germany
Freelance Developer
Mundwerk AG
- Project management and lead development in the LUCY project for a telecommunications customer to build an automated dating telephone hotline with speech recognition
- Development of a multiparty conferencing platform
Jan 2002 - Dec 2003
1 year Düsseldorf, Germany
Freelance Developer
conVISUAL AG / Apollis
- Design and implementation of a J2ME application for photos, album organization and sending via the conVISUAL MMS platform with automatic device adaptation
Jan 1999 - Dec 2003
3 years Berlin, Germany
Co-founder and Technical Director
Mundwerk AG
- First ASP-capable VoiceXML platform in Europe for Internet-based speech recognition via landline and mobile phones
- Co-founder of Mundwerk AG, built and led development, operations and support departments with over ten employees
- Procurement and management of suppliers and presentations at trade shows, conferences and specialist events
- Market-ready agile product development within six months
- Successful projects for T-Online, Jamba, clever-tanken.de, Viterra Energy Services and Colgate Palmolive
- Supported the trade sale to Excelsis/Almato
Jan 1999 - Dec 2002
2 years Düsseldorf, Germany
Freelance Consultant
conVISUAL AG
- MMB is a platform for mobile messaging apps with SMS/MMS, WAP and other technologies as a basis for conVISUAL’s ASP services
- Analysis and design with an agile development team after founding, specification and prototype development, coaching and training
- Java EE, WebSphere, UML, WAP, SMS/MMS
Jan 1999 - Dec 2000
1 year Ratingen, Germany
Technical Project Manager
S3 AG
- System architecture and project management in creating a web-based Java platform for CRM applications
- Leading development teams in Ratingen, Hamburg and Sofia
Jan 1998 - Dec 2000
3 years Düsseldorf, Germany
Technical Project Manager
NADS GmbH
- Developer and technical project manager of the J2EE-based product Pixelboxx for managing photo/video inventories in agencies
- Spin-off into an independent company
Jan 1996 - Dec 1998
3 years Dortmund, Germany
Software Developer
NADS GmbH
- Based on PERL, C/C++ and others for SPD NRW, rational Küchen
Jan 1993 - Dec 1995
2 years Dortmund, Germany
Student Assistant
Chair of AI, Computer Science, University of Dortmund
Summary
My overarching goal is to create sustainable added value for innovations in products and services in telecommunications, IT and other industries by applying proven experience, either as part of a development team or as an independent consultant for technical staff and management. My intrinsic motivation is the joy of building sustainable technical solutions for challenging use cases. In doing so, I am committed to a systematic approach and preferably follow agile methodologies. In addition to my interest and a broad base of generalist knowledge, I have acquired specific expertise that I particularly enjoy bringing to new product and service developments.
Languages
German
Native
English
Advanced
Spanish
Elementary
Education
Oct 1992 - Jun 1999
University of Dortmund
Diploma in Computer Science · Computer Science · Germany · very good
Certifications & licenses
Certified Scrum Master
Scrum Alliance
Brainbench J2EE Master
Brainbench
VoiceObjects
VoiceObjects
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