Jens Grassel
Remote
Experience
Shijou GmbH
- Software architecture and backend development for a marketplace solution / eCommerce retail
- Used Scala, Python, http4s, Next.js, Elasticsearch, PostgreSQL, AWS
Toll Collect
- Analysis and processing of sensor data
- Quality assurance of algorithms within a cluster solution based on Spark, Kafka and Cassandra
- Implementation in Scala and Java
- Utilized Docker, Scrum, AWS, Google Cloud, Jira and Confluence
Fashion Digital GmbH & Co. KG
- Backend development with Scala and Akka for the Product Data team in the e-commerce division
- Further development of the platform using Kotlin and Cloud Bigtable
EWE AG
- Ported existing REST services and AWS Lambdas to Akka and Apache Spark
- Designed and implemented a new AWS infrastructure and new services
- Worked with Python, Flask, RabbitMQ, DocumentDB, AWS, microservices, PL/pgSQL, REST APIs, Docker, Kubernetes, CI/CD, GitLab and Scrum
Shijou GmbH
- Developed a marketplace solution and e-commerce retail platform
- Used Scala, Python, http4s, Next.js, Elasticsearch, PostgreSQL, AWS
Remote
carIT AG
- Project planning and system architecture
- Backend development with Java, Jenkins and MySQL
- Analyzed and audited code of an auto-auction platform based on Java and Spring
- Initiated and planned modernization and merging of multiple sub-platforms
- Developed a refactoring concept for the entire IT infrastructure including hosting
Remote
Parfümerie Douglas GmbH
- Maintained and enhanced the online shop based on Play Frameworks and the Hybris e-commerce platform in Java
- Introduced functional programming in Scala for backend teams
- Developed new services for data integration tasks
Project
Centogene AG
- Conceptualized and developed a big-data environment for processing large volumes of laboratory measurement data for biomarker analysis
- Integrated raw data into processing pipelines using Flink, Cassandra and Kafka
Remote
Recogizer Group
- Developed new and extended existing microservices in the IoT data domain as a foundation for ML systems
Remote
Free2Move (Carjump)
- Analyzed and enhanced an existing service architecture
- Onboarded and supported new developers
- Designed and implemented new services based on given requirements
Project
The Zene AG
- Developed services and search indexes to provide web and image search via REST APIs for a website and an app
- Used Scala, Java and Elasticsearch
Product Development
Wegtam GmbH
- Developed a data aggregation and analysis tool (Tensei-Data)
- Built an enterprise search solution (Wegtam Search Agent) using Java and Elasticsearch
- Employed Scala, Akka, Play Framework and SQL
CTO / Founder
Wegtam GmbH
- Founded and led the company
- Developed Tensei-Data for data integration and the Wegtam Search Agent for enterprise search
- Utilized Scala, Akka, Play, Elasticsearch and PL/pgSQL
Technical Director
Telematika GmbH
- Directed programming and development efforts
- Implemented CRM, DMS, ERP, CMS and e-learning systems
Project Management
nexico Consulting GmbH
- Led projects and programming teams
- Worked on data mining, BI and software development
Internet services and software development
Freelancer
- Provided programming, web application development and consulting services
Trainee
Vinci Energies - Controlmatic GmbH
- Worked on automation technology, programming and software development
Industries Experience
See where this freelancer has spent most of their professional time. Longer bars indicate deeper hands-on experience, while shorter ones reflect targeted or project-based work.
Experienced in Information Technology (18.5 years), Retail (5.5 years), Energy (4 years), Cosmetics (2 years), Professional Services (2 years), and Fashion (1 year).
Business Areas Experience
The graph below provides a cumulative view of the freelancer's experience across multiple business areas, calculated from completed and active engagements. It highlights the areas where the freelancer has most frequently contributed to planning, execution, and delivery of business outcomes.
Experienced in Information Technology (22.5 years), Product Development (22.5 years), Project Management (2 years), Business Intelligence (2 years), Quality Assurance (1 year), and Research and Development (0.5 years).
Skills
- Programming Languages: Abap, Ada, Assembly, C, C++, Clojure, Common Lisp, Delphi, Java, Javascript, Kotlin, Lua, Pascal, Perl, Php, Prolog, Python, R, Ruby, Scala, Shell Scripts (Bash, Zsh), Sql (Pl/pgsql)
- Frameworks/toolkits: Akka, Apache Spark, Apache Zeppelin, Apache Flink, Apache Kafka, D3.js, Ember.js, Play, Ruby On Rails, Sbt, Slick
- Cloud Providers: Aws, Google Cloud
- Database Systems: Apache Cassandra, Cloud Bigtable, Derby, Elasticsearch, H2, Hive, Firebird, Microsoft Sql Server, Mysql, Oracle, Postgresql, Sqlite
- Network Knowledge: Advanced
- Server Administration: Advanced
Languages
Education
Hochschule Wismar / Universität Rostock
Diploma in Business Informatics · Business Informatics · Wismar, Germany
Profile
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