Big Data Architect, Engineer, AWS Architect, Engineer, Spark, Kafka, Streaming, Hadoop, Java, Scala
Aktualisiert am 07.05.2026
Profil
Freiberufler / Selbstständiger
Remote-Arbeit
Verfügbar ab: 07.05.2026
Verfügbar zu: 100%
davon vor Ort: 100%
Big Data
Apache Spark
Kafka
AWS
Scala
Elastic Search
Streaming
SQL
Apache Cassandra
Kubernetes
Apache Hadoop
Docker
MongoDB
DynamoDB
Git
Terraform
Neo4j
Java
Python
Azure
Databricks
Spring
Splunk
English
French
German

Einsatzorte

Einsatzorte

Berlin (+100km) Malchin (+100km)
möglich

Projekte

Projekte

4 Jahre 4 Monate
2021-08 - 2025-11

various

Technical Lead/ Lead Data Engineer
Technical Lead/ Lead Data Engineer
Real Driving Emissions (RDE) ? Real?Time Regulatory Analytics
  • Designed and implemented a Scala/Spark Streaming data product on Azure to ingest real?time vehicle telemetry from Kafka topics and compute RDE KPIs at scale.
  • Persisted results in Delta Lake on Azure and integrated with Qlik dashboards
  • LLM integration via LangGraph/MCP interfaces for regulatory stakeholders to analyse emissions behaviour across fleets.
  • Established monitoring and alerting via Splunk

GPS Anonymisation ? High?Volume Privacy?Preserving Location Analytics
  • Built PySpark/Spark pipelines on Azure Databricks leveraging Apache Sedona to anonymise thousands of GPS coordinates per second from connected vehicles.
  • Persisted anonymised datasets to Delta Lake and MongoDB
  • Integration with Open Street Maps (GIS) using LangGraph.
  • Defined metrics, monitoring and alerting in Splunk to ensure data protection and operational correctness.

Time?Series Data Merging (ML/AI) ? Large?Scale Time?Series Alignment
  • Implemented PySpark and tslearn?based UDFs to perform Dynamic Time Warping across three multivariate time?series streams, processing 5?8 billion records per run.
  • Used PyTorch models to filter and pre?select relevant segments, reducing downstream computation cost and improving quality of merged time?series datasets.
  • Persisted merged and enriched datasets into CosmoDB to support subsequent ML modelling and analytics.

Data Ingestion Pipelines Implementation & Maintenance
  • Built Scala/Python Spark pipelines on Azure Databricks and Airflow to ingest, cleanse and stage vehicle and telemetry data from Kafka streams into Delta Lake.
  • Standardised ingestion patterns, including schema management, partitioning strategies and error handling, enabling downstream teams to onboard data faster.
  • Established metrics and operational dashboards in Splunk, improving incident response and data quality visibility.

Data Quality Monitoring & Data Catalogue (Collibra)
  • Implemented automated schema publishing via GitLab CI/CD to ensure that changes to data contracts were tracked and governed.
  • Integrated data products with Collibra as a central data catalogue, improving discoverability, lineage visibility and ownership clarity.

RT Vehicle Charging Monitoring (VILSA) ? EV Charging Analytics
  • Developed a Scala/Databricks Spark Streaming?based product to monitor electric vehicle charging sessions in real time using Kafka as the ingestion backbone.
  • Persisted vehicle charging state in CosmosDB for low?latency updates and stateful tracking, and exposed KPIs via Splunk and a Qlik?based frontend.
  • Enabled operational teams to detect anomalies and issues in charging infrastructure quickly.

Analytics Automation (Blueprint Pipeline)
  • Built a PySpark?based on Azure Databricks framework to allow data analysts and data scientists to plug in analytics code and run it safely on production data.
  • Enforced tests via GitLab hooks, and standardised results persistence to Iceberg.
  • Reduced time?to?production for new analytics from weeks to days by encapsulating patterns for job orchestration, validation and logging.
Porsche AG, Stuttgart
2 Jahre 3 Monate
2019-03 - 2021-05

various projects

Solution Architect/Lead Engineer
Solution Architect/Lead Engineer
Data Ingestion of CDC Data 
Kunde: Daimler AG, Stuttgart
  • Designed Scala/Java ingestion pipelines to consume Oracle CDC data via Oracle GoldenGate connectors into Kafka, providing a near real?time mirror of transactional systems.
  • Implemented enrichment logic using Kafka Streams and Spark Streaming, transforming CDC events into analytics?ready structures.
  • Landed data into Amazon S3 for query via Athena and integrated Prometheus/Grafana dashboards for performance and reliability monitoring.

Distribution Processing Application 
Kunde: BMW AG, München
  • Led design of an AWS/Java application for forecasting supply and demand across multiple locations using data streamed from on?prem Kafka into Kinesis via Direct Connect and custom Kafka?to?Kinesis connectors on Fargate.
  • Utilised Kinesis Analytics for real?time grouping and aggregation, storing enriched results in Aurora (PostgreSQL flavour) and using DynamoDB as a cache layer.
  • Delivered dashboards through QuickSight and enabled Power BI access via JDBC; orchestrated ETL workloads with EMR/Spark; configured CloudWatch/SNS for logs and alerts.

Streaming Data Platform with ML Workbench 
Kunde: Böhringer Ingelheim AG (Remote)
  • Conducted use?case analysis and designed an AWS?based streaming platform centred on Kinesis and Lambda for event ingestion and processing.
  • Designed persistence strategy using S3, DynamoDB and Aurora to support batch, key?value and relational access patterns.
  • Integrated SageMaker as a machine learning workbench

Localized Location Search 
Kunde: BMW AG, München
  • Implemented an AWS/Java microservices?based solution providing low?latency location search for connected cars.
  • Used Terraform for infrastructure as code, Direct Connect and VPCs for secure hybrid connectivity and EMR/Spark for ETL processing.
  • Utilised S3 and REST APIs for third?party integrations, Aurora and DynamoDB for persistence, API Gateway for access control and monitoring, and CloudWatch/SNS for observability.

Autonomous Driving in Factory 
Kunde: BMW AG, München
  • Designed an AWS/Java solution that ingested real?time car positions as Kinesis streams to orchestrate autonomous movement between factory stations.
  • Implemented Lambda functions and backend services using Aurora and DynamoDB to compute and persist the next positions and states of vehicles.
  • Used EMR/Spark and Glue for ETL on historical data and CloudWatch/SNS for monitoring operational behaviour.

AI Building Blocks 
Kunde: BMW AG, München
  • Developed an event?driven ML platform where KStreams applications on Kubernetes/OpenShift consumed Kafka events and applied ML models in real time.
  • Integrated KubeFlow for model deployment and lifecycle management, and DVC for model version control and reproducibility.
  • Used Neo4j as a graph database for relational search and exposed a GraphQL microservices layer on OpenShift for flexible querying.
various
3 Jahre 2 Monate
2016-01 - 2019-02

various projects

Lead Data Engineer/Architect
Lead Data Engineer/Architect
Data Ingestion as a Service ? GDPR?Compliant Pipelines
  • Led design of a Kubernetes?based ?Ingestion as a Service? product allowing teams to deploy GDPR?aware ingestion pipelines with minimal effort.
  • Implemented Scala?based microservices (Akka HTTP) as event proxies, Kafka on Kubernetes via Strimzi, and Avro schema validators and transformers for PII handling.
  • Supported sinks for Hive, S3, Cassandra and Kafka, and integrated Prometheus/Grafana monitoring.

User Profiles ? Near Real?Time Personalisation
  • Architected a Scala/Spark solution that consumed click events from Kafka and generated user profiles in near real time.
  • Combined Spark Streaming for online updates with Spark Batch for computing priors, storing priors in MongoDB and profiles in Cassandra.
  • Built Akka HTTP microservices to serve user profiles with sub?50 ms latency at up to 5000 requests/second; instrumented dashboards via Kibana and Prometheus/Grafana.

Price Transparency ? ML?Driven Price Labels
  • Developed a Scala/Kafka?based system that applied ML models (Random Forests exported from H2O .ai and stored as JSON in MongoDB) to incoming listing change events.
  • Used KStreams to enrich listings with ML?derived price categories and built Akka HTTP microservices to serve price transparency and average price information.
  • Integrated Kibana dashboards and Prometheus/Grafana

GDPR Platform ? Right to Access & Right to be Forgotten
  • Designed and implemented a Java/Scala/Spark framework extending existing data capabilities with GDPR functionality.
  • Introduced Bloom filters for efficient historical data search and leveraged Cassandra tombstones to process ?right to be forgotten? requests.
  • Built Spring Boot microservices for the serving layer and integrated Prometheus/Grafana for operational visibility.

Personalized Recommendation Engine ? User?Centric Recommendations
  • Architected a Java/ElasticSearch?based recommendation engine that combined user profiles from Cassandra with item attributes in ElasticSearch.
  • Served TensorFlow models via TensorFlow Serving and stored profile priors in MongoDB; designed ElasticSearch schemas and queries to achieve <50 ms latency for ~1600 requests/ second.
  • Implemented decay?based ranking and preference modelling, contributing to a significant uplift in conversion; ensured observability through Kibana, Gatling load tests and Prometheus/ Grafana.

Recommendation Engine Tuning & LTR ? Item?Item Recommendations
  • Designed a Java/ElasticSearch solution for item?based recommendations using listing attributes and similarity for item?to?item suggestions.
  • Incorporated ML?derived weights from data scientists into ElasticSearch queries and scaled serving to ~1600 requests/second at 50 ms latency.
  • Implemented Learn?to?Rank?based automatic weight deduction using historical truth data
eBay AG, Berlin
6 Jahre 6 Monate
2012-09 - 2019-02

various projects

Senior Software Engineer
Senior Software Engineer
Recent User Activity ? Activity Store
  • Implemented a Scala/Cassandra/Kafka?based service that ingested user activity events via Kafka Streams and persisted them in Cassandra and PostgreSQL.
  • Exposed Spring Boot microservices for low?latency reads by downstream applications; added comprehensive metrics via Prometheus and Grafana.

Fraud Detection with Random Forests
  • Built Java/Spring services that applied trained H2O .ai models (served as POJOs) on incoming listing data to classify listings as fraudulent or non?fraudulent.
  • Integrated Kafka and logging frameworks to track decisions, and used Kibana dashboards to monitor model precision and recall over time.
  • Collaborated with data scientists to iterate on model performance and deployment patterns.

Probabilistic Fraud Detection of Listings ? Bayesian Approach
  • Designed a Java/Spring backend using Bayesian probabilistic methods to score and classify incoming listings based on multiple signals.
  • Implemented JavaScript?based user fingerprinting, Kafka and RabbitMQ as ingestion mechanisms, and MySQL/MongoDB for persistence.
  • Tracked model metrics with Kibana and Prometheus/Grafana, enabling iterative improvement.

Account Takeover Ring Detection ? Graph Analytics
  • Built a Java/Neo4j solution performing social ring analysis on login and click data to detect groups of compromised accounts.
  • Modelled relationships and behaviours in Neo4j and implemented graph queries that significantly reduced platform ATO incidents.

Dealer Rating Platform ? Ratings, Reviews & Fraud Checks
  • Developed a Java/Spring microservices?based platform for persisting, fetching and displaying dealer ratings, supported by MySQL and MongoDB via Hibernate.
  • Implemented near real?time fraud detection for reviews using Kafka/KStreams and Spark Streaming and batch ETL via Spark Core.
  • Used Logstash and ElasticSearch for search and visualisation, with Gattling for load testing and Prometheus/Grafana for metrics.
eBay AG, Berlin
4 Jahre 10 Monate
2007-08 - 2012-05

Push Email and Calendar ? Mobile Gateway Product

Software Backend Engineer (J2EE)
Software Backend Engineer (J2EE)
  • Worked on a Java/Spring multi?tier ?Mobile Gateway? product synchronising non?smartphones with email (push email), calendar and contacts.
  • Used Hibernate and PostgreSQL for persistence, JSP/JSF/JavaScript/CSS for front?end components and implemented support for multiple protocols (SyncML, IMAP, XMPP, ActiveSync).
  • Contributed to open?source efforts (e.g., as a committer to the Open Data Sync project), improving interoperability and standards support.
Synchronica GmbH, Berlin
1 Jahr 9 Monate
2005-09 - 2007-05

various

Intern/ Werkstudent/ Thesis
Intern/ Werkstudent/ Thesis

Master Thesis: Enterprise Semantic Search

  • Developed an enterprise semantic search solution supporting multiple file formats and knowledge extraction.
  • Implemented named entity detection and text transformation pipelines using Lucene, OpenNLP and UIMA to build searchable indexes.

Intern & Werkstudent ? Project Completion Centre
  • Implemented enhancements for a Matrix PLM system using JSP, JSF, JavaScript and CSS to improve usability and workflow support.

    Lufthansa Technik AG, Hamburg

    Aus- und Weiterbildung

    Aus- und Weiterbildung

    2 Jahre 4 Monate
    2004-09 - 2006-12

    Software Technology

    Master, Universität Lüneburg, Lüneburg
    Master
    Universität Lüneburg, Lüneburg
    3 Jahre 10 Monate
    2000-08 - 2004-05

    Computer Science Engineering

    Bachelor, University of Madras, Chennai, India
    Bachelor
    University of Madras, Chennai, India

    Position

    Position

    Lead Backend Engineer/Architect

    Kompetenzen

    Kompetenzen

    Top-Skills

    Big Data Apache Spark Kafka AWS Scala Elastic Search Streaming SQL Apache Cassandra Kubernetes Apache Hadoop Docker MongoDB DynamoDB Git Terraform Neo4j Java Python Azure Databricks Spring Splunk

    Produkte / Standards / Erfahrungen / Methoden

    Profile
    Senior Technical Lead and Backend Engineer/Software Architect with 20 years of experience architecting and delivering large-scale backend services and distributed systems in automotive, e-commerce, consulting, and telecom. Expert in Java and Scala ecosystems, real-time and event-driven architectures and high-performance service platforms, with a strong track record of designing and building reusable backend frameworks and scalable software solutions that drive measurable business impact.


    Skills
    • Java
    • Scala
    • SQL Databases
    • NoSQL (Cassandra, MongoDB, DynamoDB)
    • AWS
    • Streaming Platforms (Kafka)
    • Apache Spark
    • Hadoop Ecosystem
    • Elasticsearch
    • Docker/Kubernetes
    • Openshift
    • Python
    • Recommendation Engines
    • ML Integration
    • Git
    • Terraform

    CORE PROJECT DOMAINS
    • Backend platforms & distributed systems: Service-oriented backend platforms, event-driven architectures, integration layers, and reusable engineering frameworks.
    • Recommendation & personalization systems: User profile services, item-based and personalized recommendation engines, marketplace-scale pricing transparency, and predictive labeling solutions.
    • Fraud, risk & security systems: ML-powered fraud detection, probabilistic and graph-based account takeover prevention, risk support tooling, and GDPR-compliant backend platforms.
    • Search & knowledge systems: Enterprise semantic search, knowledge graph platforms, Elasticsearch-based search and ranking, and low-latency query services.
    • Connected vehicles & automotive platforms: Real-time vehicle telemetry services, RDE analytics platforms, GPS anonymisation systems, EV charging monitoring, and backend solutions for autonomous driving logistics in factory environments.
    • Telecom & messaging platforms: Mobile gateway services for push email, calendar, and contacts, including protocol implementation.

    Technologies
    • Cloud
      • AWS, Azure, Databricks, OpenShift
    • Big Data, Search and Visualisation
      • Spark, Kafka, Elastic Search, Iceberg, Cassandra, MongoDB, Hadoop Ecosystem, Cloudera, Delta Lake, Impala, Qlik, DynamoDB, Aurora, Neo4J, Collibra, EMR, Qlik, Tableau, Lucene, UIMA
    • Machine Learning/AI
      • SageMaker, LangGraph, TensorFlow Serving, MCP
    • Containerisation
      • Docker, Kubernetes
    • Backend and Services
      • Spring, Akka, Play Framework, Streamlit
    • DevOPs and Monitoring
      • GitLab, BitBucket, Terraform (IaaC), Jenkins, Grafana, Splunk, Promotheus, Cloud Watch

    PROFESSIONAL EXPERIENCE (OVERVIEW)
    08/2021 - 11/2025
    Technical Lead Data Engineer 
    Porsche AG, Stuttgart (Freelancer/Contracts)

    03/2019 - 05/2021
    Solution Architect/ Lead Engineer 
    Deloitte Consulting GmbH, Berlin

    01/2016 - 02/2019
    Lead Data Engineer/ Architect 
    eBay AG, Berlin

    09/2012 - 02/2019
    Senior Software Engineer 
    eBay AG, Berlin

    08/2007 - 05/2012
    Software Backend Engineer (J2EE) 
    Synchronica GmbH, Berlin

    09/2005 - 05/2007
    Intern/ Werkstudent/ Thesis 
    Lufthansa Technik AG, Hamburg

      Programmiersprachen

      Java
      Python
      Scala

      Einsatzorte

      Einsatzorte

      Berlin (+100km) Malchin (+100km)
      möglich

      Projekte

      Projekte

      4 Jahre 4 Monate
      2021-08 - 2025-11

      various

      Technical Lead/ Lead Data Engineer
      Technical Lead/ Lead Data Engineer
      Real Driving Emissions (RDE) ? Real?Time Regulatory Analytics
      • Designed and implemented a Scala/Spark Streaming data product on Azure to ingest real?time vehicle telemetry from Kafka topics and compute RDE KPIs at scale.
      • Persisted results in Delta Lake on Azure and integrated with Qlik dashboards
      • LLM integration via LangGraph/MCP interfaces for regulatory stakeholders to analyse emissions behaviour across fleets.
      • Established monitoring and alerting via Splunk

      GPS Anonymisation ? High?Volume Privacy?Preserving Location Analytics
      • Built PySpark/Spark pipelines on Azure Databricks leveraging Apache Sedona to anonymise thousands of GPS coordinates per second from connected vehicles.
      • Persisted anonymised datasets to Delta Lake and MongoDB
      • Integration with Open Street Maps (GIS) using LangGraph.
      • Defined metrics, monitoring and alerting in Splunk to ensure data protection and operational correctness.

      Time?Series Data Merging (ML/AI) ? Large?Scale Time?Series Alignment
      • Implemented PySpark and tslearn?based UDFs to perform Dynamic Time Warping across three multivariate time?series streams, processing 5?8 billion records per run.
      • Used PyTorch models to filter and pre?select relevant segments, reducing downstream computation cost and improving quality of merged time?series datasets.
      • Persisted merged and enriched datasets into CosmoDB to support subsequent ML modelling and analytics.

      Data Ingestion Pipelines Implementation & Maintenance
      • Built Scala/Python Spark pipelines on Azure Databricks and Airflow to ingest, cleanse and stage vehicle and telemetry data from Kafka streams into Delta Lake.
      • Standardised ingestion patterns, including schema management, partitioning strategies and error handling, enabling downstream teams to onboard data faster.
      • Established metrics and operational dashboards in Splunk, improving incident response and data quality visibility.

      Data Quality Monitoring & Data Catalogue (Collibra)
      • Implemented automated schema publishing via GitLab CI/CD to ensure that changes to data contracts were tracked and governed.
      • Integrated data products with Collibra as a central data catalogue, improving discoverability, lineage visibility and ownership clarity.

      RT Vehicle Charging Monitoring (VILSA) ? EV Charging Analytics
      • Developed a Scala/Databricks Spark Streaming?based product to monitor electric vehicle charging sessions in real time using Kafka as the ingestion backbone.
      • Persisted vehicle charging state in CosmosDB for low?latency updates and stateful tracking, and exposed KPIs via Splunk and a Qlik?based frontend.
      • Enabled operational teams to detect anomalies and issues in charging infrastructure quickly.

      Analytics Automation (Blueprint Pipeline)
      • Built a PySpark?based on Azure Databricks framework to allow data analysts and data scientists to plug in analytics code and run it safely on production data.
      • Enforced tests via GitLab hooks, and standardised results persistence to Iceberg.
      • Reduced time?to?production for new analytics from weeks to days by encapsulating patterns for job orchestration, validation and logging.
      Porsche AG, Stuttgart
      2 Jahre 3 Monate
      2019-03 - 2021-05

      various projects

      Solution Architect/Lead Engineer
      Solution Architect/Lead Engineer
      Data Ingestion of CDC Data 
      Kunde: Daimler AG, Stuttgart
      • Designed Scala/Java ingestion pipelines to consume Oracle CDC data via Oracle GoldenGate connectors into Kafka, providing a near real?time mirror of transactional systems.
      • Implemented enrichment logic using Kafka Streams and Spark Streaming, transforming CDC events into analytics?ready structures.
      • Landed data into Amazon S3 for query via Athena and integrated Prometheus/Grafana dashboards for performance and reliability monitoring.

      Distribution Processing Application 
      Kunde: BMW AG, München
      • Led design of an AWS/Java application for forecasting supply and demand across multiple locations using data streamed from on?prem Kafka into Kinesis via Direct Connect and custom Kafka?to?Kinesis connectors on Fargate.
      • Utilised Kinesis Analytics for real?time grouping and aggregation, storing enriched results in Aurora (PostgreSQL flavour) and using DynamoDB as a cache layer.
      • Delivered dashboards through QuickSight and enabled Power BI access via JDBC; orchestrated ETL workloads with EMR/Spark; configured CloudWatch/SNS for logs and alerts.

      Streaming Data Platform with ML Workbench 
      Kunde: Böhringer Ingelheim AG (Remote)
      • Conducted use?case analysis and designed an AWS?based streaming platform centred on Kinesis and Lambda for event ingestion and processing.
      • Designed persistence strategy using S3, DynamoDB and Aurora to support batch, key?value and relational access patterns.
      • Integrated SageMaker as a machine learning workbench

      Localized Location Search 
      Kunde: BMW AG, München
      • Implemented an AWS/Java microservices?based solution providing low?latency location search for connected cars.
      • Used Terraform for infrastructure as code, Direct Connect and VPCs for secure hybrid connectivity and EMR/Spark for ETL processing.
      • Utilised S3 and REST APIs for third?party integrations, Aurora and DynamoDB for persistence, API Gateway for access control and monitoring, and CloudWatch/SNS for observability.

      Autonomous Driving in Factory 
      Kunde: BMW AG, München
      • Designed an AWS/Java solution that ingested real?time car positions as Kinesis streams to orchestrate autonomous movement between factory stations.
      • Implemented Lambda functions and backend services using Aurora and DynamoDB to compute and persist the next positions and states of vehicles.
      • Used EMR/Spark and Glue for ETL on historical data and CloudWatch/SNS for monitoring operational behaviour.

      AI Building Blocks 
      Kunde: BMW AG, München
      • Developed an event?driven ML platform where KStreams applications on Kubernetes/OpenShift consumed Kafka events and applied ML models in real time.
      • Integrated KubeFlow for model deployment and lifecycle management, and DVC for model version control and reproducibility.
      • Used Neo4j as a graph database for relational search and exposed a GraphQL microservices layer on OpenShift for flexible querying.
      various
      3 Jahre 2 Monate
      2016-01 - 2019-02

      various projects

      Lead Data Engineer/Architect
      Lead Data Engineer/Architect
      Data Ingestion as a Service ? GDPR?Compliant Pipelines
      • Led design of a Kubernetes?based ?Ingestion as a Service? product allowing teams to deploy GDPR?aware ingestion pipelines with minimal effort.
      • Implemented Scala?based microservices (Akka HTTP) as event proxies, Kafka on Kubernetes via Strimzi, and Avro schema validators and transformers for PII handling.
      • Supported sinks for Hive, S3, Cassandra and Kafka, and integrated Prometheus/Grafana monitoring.

      User Profiles ? Near Real?Time Personalisation
      • Architected a Scala/Spark solution that consumed click events from Kafka and generated user profiles in near real time.
      • Combined Spark Streaming for online updates with Spark Batch for computing priors, storing priors in MongoDB and profiles in Cassandra.
      • Built Akka HTTP microservices to serve user profiles with sub?50 ms latency at up to 5000 requests/second; instrumented dashboards via Kibana and Prometheus/Grafana.

      Price Transparency ? ML?Driven Price Labels
      • Developed a Scala/Kafka?based system that applied ML models (Random Forests exported from H2O .ai and stored as JSON in MongoDB) to incoming listing change events.
      • Used KStreams to enrich listings with ML?derived price categories and built Akka HTTP microservices to serve price transparency and average price information.
      • Integrated Kibana dashboards and Prometheus/Grafana

      GDPR Platform ? Right to Access & Right to be Forgotten
      • Designed and implemented a Java/Scala/Spark framework extending existing data capabilities with GDPR functionality.
      • Introduced Bloom filters for efficient historical data search and leveraged Cassandra tombstones to process ?right to be forgotten? requests.
      • Built Spring Boot microservices for the serving layer and integrated Prometheus/Grafana for operational visibility.

      Personalized Recommendation Engine ? User?Centric Recommendations
      • Architected a Java/ElasticSearch?based recommendation engine that combined user profiles from Cassandra with item attributes in ElasticSearch.
      • Served TensorFlow models via TensorFlow Serving and stored profile priors in MongoDB; designed ElasticSearch schemas and queries to achieve <50 ms latency for ~1600 requests/ second.
      • Implemented decay?based ranking and preference modelling, contributing to a significant uplift in conversion; ensured observability through Kibana, Gatling load tests and Prometheus/ Grafana.

      Recommendation Engine Tuning & LTR ? Item?Item Recommendations
      • Designed a Java/ElasticSearch solution for item?based recommendations using listing attributes and similarity for item?to?item suggestions.
      • Incorporated ML?derived weights from data scientists into ElasticSearch queries and scaled serving to ~1600 requests/second at 50 ms latency.
      • Implemented Learn?to?Rank?based automatic weight deduction using historical truth data
      eBay AG, Berlin
      6 Jahre 6 Monate
      2012-09 - 2019-02

      various projects

      Senior Software Engineer
      Senior Software Engineer
      Recent User Activity ? Activity Store
      • Implemented a Scala/Cassandra/Kafka?based service that ingested user activity events via Kafka Streams and persisted them in Cassandra and PostgreSQL.
      • Exposed Spring Boot microservices for low?latency reads by downstream applications; added comprehensive metrics via Prometheus and Grafana.

      Fraud Detection with Random Forests
      • Built Java/Spring services that applied trained H2O .ai models (served as POJOs) on incoming listing data to classify listings as fraudulent or non?fraudulent.
      • Integrated Kafka and logging frameworks to track decisions, and used Kibana dashboards to monitor model precision and recall over time.
      • Collaborated with data scientists to iterate on model performance and deployment patterns.

      Probabilistic Fraud Detection of Listings ? Bayesian Approach
      • Designed a Java/Spring backend using Bayesian probabilistic methods to score and classify incoming listings based on multiple signals.
      • Implemented JavaScript?based user fingerprinting, Kafka and RabbitMQ as ingestion mechanisms, and MySQL/MongoDB for persistence.
      • Tracked model metrics with Kibana and Prometheus/Grafana, enabling iterative improvement.

      Account Takeover Ring Detection ? Graph Analytics
      • Built a Java/Neo4j solution performing social ring analysis on login and click data to detect groups of compromised accounts.
      • Modelled relationships and behaviours in Neo4j and implemented graph queries that significantly reduced platform ATO incidents.

      Dealer Rating Platform ? Ratings, Reviews & Fraud Checks
      • Developed a Java/Spring microservices?based platform for persisting, fetching and displaying dealer ratings, supported by MySQL and MongoDB via Hibernate.
      • Implemented near real?time fraud detection for reviews using Kafka/KStreams and Spark Streaming and batch ETL via Spark Core.
      • Used Logstash and ElasticSearch for search and visualisation, with Gattling for load testing and Prometheus/Grafana for metrics.
      eBay AG, Berlin
      4 Jahre 10 Monate
      2007-08 - 2012-05

      Push Email and Calendar ? Mobile Gateway Product

      Software Backend Engineer (J2EE)
      Software Backend Engineer (J2EE)
      • Worked on a Java/Spring multi?tier ?Mobile Gateway? product synchronising non?smartphones with email (push email), calendar and contacts.
      • Used Hibernate and PostgreSQL for persistence, JSP/JSF/JavaScript/CSS for front?end components and implemented support for multiple protocols (SyncML, IMAP, XMPP, ActiveSync).
      • Contributed to open?source efforts (e.g., as a committer to the Open Data Sync project), improving interoperability and standards support.
      Synchronica GmbH, Berlin
      1 Jahr 9 Monate
      2005-09 - 2007-05

      various

      Intern/ Werkstudent/ Thesis
      Intern/ Werkstudent/ Thesis

      Master Thesis: Enterprise Semantic Search

      • Developed an enterprise semantic search solution supporting multiple file formats and knowledge extraction.
      • Implemented named entity detection and text transformation pipelines using Lucene, OpenNLP and UIMA to build searchable indexes.

      Intern & Werkstudent ? Project Completion Centre
      • Implemented enhancements for a Matrix PLM system using JSP, JSF, JavaScript and CSS to improve usability and workflow support.

        Lufthansa Technik AG, Hamburg

        Aus- und Weiterbildung

        Aus- und Weiterbildung

        2 Jahre 4 Monate
        2004-09 - 2006-12

        Software Technology

        Master, Universität Lüneburg, Lüneburg
        Master
        Universität Lüneburg, Lüneburg
        3 Jahre 10 Monate
        2000-08 - 2004-05

        Computer Science Engineering

        Bachelor, University of Madras, Chennai, India
        Bachelor
        University of Madras, Chennai, India

        Position

        Position

        Lead Backend Engineer/Architect

        Kompetenzen

        Kompetenzen

        Top-Skills

        Big Data Apache Spark Kafka AWS Scala Elastic Search Streaming SQL Apache Cassandra Kubernetes Apache Hadoop Docker MongoDB DynamoDB Git Terraform Neo4j Java Python Azure Databricks Spring Splunk

        Produkte / Standards / Erfahrungen / Methoden

        Profile
        Senior Technical Lead and Backend Engineer/Software Architect with 20 years of experience architecting and delivering large-scale backend services and distributed systems in automotive, e-commerce, consulting, and telecom. Expert in Java and Scala ecosystems, real-time and event-driven architectures and high-performance service platforms, with a strong track record of designing and building reusable backend frameworks and scalable software solutions that drive measurable business impact.


        Skills
        • Java
        • Scala
        • SQL Databases
        • NoSQL (Cassandra, MongoDB, DynamoDB)
        • AWS
        • Streaming Platforms (Kafka)
        • Apache Spark
        • Hadoop Ecosystem
        • Elasticsearch
        • Docker/Kubernetes
        • Openshift
        • Python
        • Recommendation Engines
        • ML Integration
        • Git
        • Terraform

        CORE PROJECT DOMAINS
        • Backend platforms & distributed systems: Service-oriented backend platforms, event-driven architectures, integration layers, and reusable engineering frameworks.
        • Recommendation & personalization systems: User profile services, item-based and personalized recommendation engines, marketplace-scale pricing transparency, and predictive labeling solutions.
        • Fraud, risk & security systems: ML-powered fraud detection, probabilistic and graph-based account takeover prevention, risk support tooling, and GDPR-compliant backend platforms.
        • Search & knowledge systems: Enterprise semantic search, knowledge graph platforms, Elasticsearch-based search and ranking, and low-latency query services.
        • Connected vehicles & automotive platforms: Real-time vehicle telemetry services, RDE analytics platforms, GPS anonymisation systems, EV charging monitoring, and backend solutions for autonomous driving logistics in factory environments.
        • Telecom & messaging platforms: Mobile gateway services for push email, calendar, and contacts, including protocol implementation.

        Technologies
        • Cloud
          • AWS, Azure, Databricks, OpenShift
        • Big Data, Search and Visualisation
          • Spark, Kafka, Elastic Search, Iceberg, Cassandra, MongoDB, Hadoop Ecosystem, Cloudera, Delta Lake, Impala, Qlik, DynamoDB, Aurora, Neo4J, Collibra, EMR, Qlik, Tableau, Lucene, UIMA
        • Machine Learning/AI
          • SageMaker, LangGraph, TensorFlow Serving, MCP
        • Containerisation
          • Docker, Kubernetes
        • Backend and Services
          • Spring, Akka, Play Framework, Streamlit
        • DevOPs and Monitoring
          • GitLab, BitBucket, Terraform (IaaC), Jenkins, Grafana, Splunk, Promotheus, Cloud Watch

        PROFESSIONAL EXPERIENCE (OVERVIEW)
        08/2021 - 11/2025
        Technical Lead Data Engineer 
        Porsche AG, Stuttgart (Freelancer/Contracts)

        03/2019 - 05/2021
        Solution Architect/ Lead Engineer 
        Deloitte Consulting GmbH, Berlin

        01/2016 - 02/2019
        Lead Data Engineer/ Architect 
        eBay AG, Berlin

        09/2012 - 02/2019
        Senior Software Engineer 
        eBay AG, Berlin

        08/2007 - 05/2012
        Software Backend Engineer (J2EE) 
        Synchronica GmbH, Berlin

        09/2005 - 05/2007
        Intern/ Werkstudent/ Thesis 
        Lufthansa Technik AG, Hamburg

          Programmiersprachen

          Java
          Python
          Scala

          Vertrauen Sie auf Randstad

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