Sven Hohlfeld

Full-Stack Developer

Sven Hohlfeld
Hannover, Germany

Experience

Sep 2024 - Present
6 months
Germany

Full-Stack Developer - CPIL App & Config Team

Bayer AG

Support in the stabilization of the product and service landscape of the platform team in the context of approx. 100 Github repositories with approx. 4,000,000 lines of code.

Development activities:

  • Creation of data migration for event sourcing, adaptation and standardization of bilingual libraries (python, go)
  • Participation in ADRs
  • Planning and supporting the transfer of repository responsibilities to other teams
Jul 2024 - Present
8 months
Germany

Full-Stack Developer - SD/UI

Techem AG

Further development of the back office management tool for the administration of services for property-related charging stations & charging station networks.

Development activity:

  • Implementation of requirements in Spring-Boot backend and React frontend. Deployment as Azure-Function Bundle in Azure
  • Support of the POs in sharpening requirements, stabilization of the agile grown frontend
Apr 2024 - Aug 2024
5 months
Germany

J2EE Developer - CPC

NordLB

Further development and maintenance of an approx. 20 year old, mature application for the risk-adjusted interest calculation of large loans. In addition to general development activities, I created an analysis tool that searches the Git history for keywords in order to create configuration files, which in turn had an influence on the QA process.

Oct 2023 - Mar 2024
6 months

Parental leave/Sabbatical

Oct 2022 - Apr 2023
7 months
Germany

Full-Stack Developer - CPIL Master Data Management

Bayer AG

Support in migration planning for the rewritten Masterdata 2 API platform supporting taxonomies and planning for the shutdown of Masterdata.

PoC for Lambda based Azure Cloud AD SAML Auth integration in AWS Lambda Authorizer.

Support in stabilizing the backend (Go/Golang programming language): fixing bugs, changing the GraphQL API

Architecture/Refactoring: I helped complete the extraction of larger software parts into separate modules due to organizational changes.

Coaching: I helped the international team with their testing skills and demonstrated how unit tests can also be introduced in Legacy Code.

Support of the product owner in shifting/transforming the existing business value into a new product vision: architecture, data sources, tech stack.

Architecture support: I started & ran several POC/investigation tickets that led to architectural decision records (ADRs). For example: alternative database types, low-code tools.

Backend: I created a prototype to import (semi-)publicly available hierarchical data (taxonomies) into a new database via various APIs and synchronize it with already available data.

Frontend: After all frontend developers (React) left the project, I helped with debugging and providing new features.

Oct 2020 - Sep 2022
2 years
Germany

Full-Stack Developer/Technical Product-Owner/Domain-Specialist

unimed Abrechnungsservice für Kliniken und Chefärzte GmbH

Focus: The first module was completed on time and on budget under increased time pressure.

Team performance: I helped introduce Gitlab CI/CD instead of AWS Code Commit in the team.

Architecture: I have emphatically supported and promoted the switch to containers instead of pure AWS services (such as Lambda).

Leading: I took a leading role in the AFM team both as a developer and as a technical product owner. Ticket requirements, requirements engineering, support PO with requirements, moderation of review and planning meetings.

Implementation: I took responsibility for the process design and implementation for API-based, paper- and scan-based processes with the result that up to 300,000 pages a day or 5,000,000 pages per month could be processed 'on premise' (from zero to production).

Focus: I helped the team to push ahead with the elimination of technical debt during several sprints.

Implementation of different lambdas.

Implementation of various React components.

Coaching: Junit-Tests/Dependency-Injection/EBI.

Coaching: Workshop "Introduction to Requirements Engineering".

Focus: Establishment of code reviews.

Business details: Data model corrections & adjustments, as well as transformation of the so-called status concept.

Process: Standardization of ticket descriptions.

Leading: Restructuring of the agile development process.

Leading: Introduction of DB Migrations.

Leading: Stabilization of the customer API (Restful & HL7).

Aug 2020 - Jan 2023
2 years 6 months
Germany

Founder

CHCKR

Development of a solution for guest registration in restaurants and pubs. Through a very simple digital recording of visitor data by scanning a QR code via smartphone, it is possible to trace reported guests including their notification in the event of a corona case. The entire system is realized as a Progressive Web App and therefore does not require installation from an app store.

Oct 2019 - Sep 2020
1 year
Germany

Full-Stack Developer - Target2

Finanzinformatik GmbH & Co. KG

I presented agile working methods (team of 80+ people) and implemented them in my area

I have introduced automated tests and implemented the necessary adjustments in the existing code.

I have clarified unclear requirements and transferred them to the relevant documents for the technically responsible persons.

I have implemented prototypical implementations of the new Swift messages so that the old messages are compatible with the new ones.

Extensive refactoring of "copy and paste driven application development" within a very old framework towards - suitable architectural patterns - in compliance with the underlying framework: introduction of EBI at the process boundary (hexagonal architectural idiom) and thus achievement of testability and architectural structure in the first place.

Introduction of automated test cases and massive increase in test coverage.

Introduction of an orderly procedure to derive technical specifications from the so-called technical concept into a ticket-based backlog (Jira).

Coordination of the introduction of the aforementioned procedure as well as team meetings/workshop - do the persuasion work.

Coordination of the content structure of the tickets.

Introduction of backlog maintenance and ticket meetings.

Technical implementation/implementation of the technical concept (development/realization), where possible.

Defining test cases in cooperation with the people responsible.

Jan 2019 - Dec 2020
1 year
Germany

Full-Stack Developer - structured financing

finpair.de

Continuation of full stack development (see preliminary project "Developer/Startup Consultant").

Jan 2018 - Dec 2020
3 years
Germany

Founder

monkeycash.io

Prototype - mobile payment system for small and very small money transactions.

Development of a first prototype for a mobile payment system based on QR codes.

The background idea was processing payments over small amounts at low frequency at high speed. The entire system is realized as a Progressive WebApp and therefore does not require installation from an app store.

Jan 2018 - Dec 2019
1 year
Germany

Full Stack Developer/Startup Consultant

Nord/LB

Planning and design of the process to be digitized with stakeholders of the analog process.

Implementation of the MVP with jboss wildfly-swarm and Angular NG (4+).

Support, planning and reinforcement of the spin-off as an independent (subsidiary) company.

Mediation and coordination of third party deliverables (design artefacts, HTML implementation).

Integration of third-party systems/interfaces/APIs such as hubspot, mailgun and idnow.

Aug 2016 - Dec 2017
1 year 5 months
Germany

Developer at NEO/Onlinebanking Processes

Finanzinformatik GmbH & Co. KG

Implementation of the customer banking process to manage online banking with Javascript and Java. Use of eclipse and Webstorm and use of the OSPlus Neo Framework. Programming with the help of central components, services and services.

  • Central printing services and DynS-based HOST interfaces
  • Banking. Banking. Concrete implementation of technical processes:
  • Edit Online Banking (customer online/stationary)
  • Create online banking contracts (customer online/stationary)
  • Manage Exemptions/NV Certificates (customer online/stationary)
  • DWP depot opening
  • Investment configurator
  • Workflow design
Apr 2015 - Jul 2016
1 year 4 months
Germany

Lead Developer/Senior Developer

Federal Authority (Customs ITZBund)

Connection of two federal authorities (Customs and Employment Agency) via soap-based interface designed after business requirements.

Reimplementation of existing specialist applications with an extended range of functions and newer technical solutions, partly by means of reverse engineering. Implementation a HTML5 web interface using a lightweight JSF variant.

  • Inter-federal-authority communication
  • Software design
  • Implementation of SOAP web service interfaces
  • Build management
  • Release management
  • Implementation of a lightweight JSF variant
  • Implementation of a Java library for the technical encapsulation of the federal-authority interface
  • Infrastructure planning and coordination of multi-level deployment
  • Coordination of firewall configuration
  • Test support
  • Implementation of automatic click tests
  • UI guidelines coordination
  • Estimation of project effort
  • Preparation for project planning
  • Requirements management - risk management
  • Requirements management - estimation and planning
  • Project support in the field of infrastructure: networks, Websphere systems, interfaces
  • Introduction of devops procedures (checklists, open task lists) between production and development
  • HTML frontend
Mar 2015 - Jun 2016
1 year 4 months
Germany

Interim IT Manager Business Development

connox.de

Planning, control and product development of the IT department.

  • Introduction of agile processes
  • Introduction of agile project management
  • Introduction of agile project planning
  • Product development B2B pricing tool (market price observing) as a "tag team"
  • Support with annual IT project planning
  • Planning and preparation of outsourcing of IT projects (Nearshoring)
  • Outsourcing of partial functions to external service providers (newsletter)
  • Support of the management in recruiting/personnel planning
  • Preparation for the introduction of structured requirements management
  • Introduction of the mobile sales channel for IOS and Android (app launch)
  • Technical lead and process coordination for internationalization (EU/non-EU, DHL, customs, forwarding) project
  • Coordination of IT requirements
Nov 2013 - Jul 2015
1 year 9 months
Germany

Lead-Developer/Senior Developer

Customs ITZBund

Connection of second federal authorities (customs and DRV) via a professional,Soap-based interface in the federal network: DOI.

Implementation in comprehensive Websphere cluster environment with application server, Webseal, Oracle database, Rational Application Developer as well as Rational Doors as requirements tool.

  • Inter-federal authority communication
  • Software design
  • Definition of SOAP web service interfaces
  • Definition of security standards
  • Implementation of SOAP web service interfaces
  • Design and implementation of an HTML5-based test Workbench based on Junit regression tests
  • Infrastructure planning and coordination build management and release management
  • Multi-level deployment test support
  • Test management
  • Test programming
  • Load test and edge test case preparation and execution
  • Requirements management - change requests
  • Requirements management - risk management
  • Requirements management - estimation and planning
  • Requirements management - Traceability
  • Project support in the field of infrastructure: networks, Websphere systems, interfaces
Dec 2011 - Mar 2013
1 year 4 months
Germany

Business Analyst/UML Modeller

Volkswagen Financial Services

Object-oriented modeling of leasing-relevant components in highly distributed SAP and mainframe system landscapes

In the specialist procedure leasing. Implementation of technical fine concepts in UML with the help of and within the framework of software architecture patterns, e.g. Entity Control Boundary (ECB) for component separation and Publish & Subscribe for system encapsulation.

  • Modeling of the software components in direct cooperation with the department and the developers
  • Onboarding of new employees with the complex software development process and the modeling guidelines
  • Support and implementation of quality gates during the creation and addition of the technical fine concepts and modeling
  • Estimation of expenses of change requests
  • Dialogue modeling in UML
Oct 2010 - Nov 2013
3 years 2 months
Germany

Managing Partner

tape.io GmbH

Managing founder and shareholder in the cloud/technology startup doctape. Asynchronous programming (nodejs), single language architecture (JavaScript), no-SQL database (CouchDB), hybrid mobile apps (Appcelerator, HTML5, IOS, Android).

  • Management activities
  • Business development
  • Roadmap management
  • Press and publicity measures
  • Employee management
  • KPI measurement (K), detection und analysis
  • Test management
Oct 2010 - Dec 2011
1 year 3 months
Germany

Project Management

Fiducia GAD AG

Implementation of the technical concept for the highly automated processing of KWG $18 compliant document requirement for german credit law (KWG $18) ready Document request in the credit procedure.

  • Creation and maintenance of project plan
  • Estimation and control of expenses
  • Planning and control of work packages
  • Status and general reporting to the client
  • Business related Contact person for the planing of project staffing
  • Implementation of internal QA measures
  • Implementation of QA measures of the contractor (for example: procedure model and framework compliance)
  • Planning and creation of test cases
  • Processing of change requests as well as their effort estimate and appropriate offer formulation
Jul 2010 - Oct 2010
4 months
Germany

Business-analyst/Conceptualizer, Technical concept

Fiducia GAD AG

Creation of the technical concept. Implemented for the highly automated processing of a KWG §18 (germany credit law) Compliant document request in the credit process. The application is integrated into the core banking system bank21 and has a high proportion of highly automated (mass) dark processing.

It determines the need for documents to be requested and controls the mass dispatch of the cover letters at certain times.

  • Accompaniment and moderation of requirement workshops
  • Creation of the technical concept in close coordination with the customer
  • Business process modeling (BPMN)
  • Use case modelling
  • Modeling of the technical data model
  • Professional service modeling (service cut)
  • Modeling of the domain class model
  • Design of desk tests
Nov 2008 - Jun 2010
1 year 8 months
Germany

Senior Developer

Nord/LB

Implementation of several banking domain specific procedures:

  • Mavis: Design and implementation of the Mavis web application to control the securities business of Nord/LB (Depot A) as part of the host front-end replacement due to the Landesbanken migration to OSPlus. Technical support for the introduction of component tests by means of Junit.
  • ADD-Base: Design, implementation, control and monitoring of the subsequent integration test of the sub-application ADD condition fees procedure as part of the BaseOne host front-end replacement due to the OSPlus migration of Nord/LB.
  • FWV-Base: Partial conception, design and implementation of the BaseOne frontend for the existing host application "foreign currency procedure", which serves the management of foreign currency accounts and clients (savings banks).
Jun 2008 - Nov 2008
6 months
Germany

Senior Developer

Nord/LB

Implementation of a domain specific banking procedure

  • DU/Udefix, Value at Risk III: Design and implementation of a plug-in module for the LDU application for liquidity control in the foreign exchange business of Nord/LB (bank control)
Aug 2007 - May 2008
10 months
Germany

Senior Developer

Nord/LB

Implementation of a domain specific banking procedure

  • Global-Cash Reengineering: Implementation of a subsystem to replace the host frontend to manage account statements for foreign currency accounts and to display SWIFT messages
  • ADD/Base Reegineering: Implementation of a subsystem to replace the host front end for managing bookings on foreign currency accounts using the BaseOne framework using DB2 and S2Skom
Jul 2007 - Aug 2007
2 months
Germany

Business-analyst, architect, project lead

CS Consulting AG

Project: GOAL - Requirements analysis, specification and development of a procedure model for SOA projects

  • Design of patterns/architectural patterns in the SOA environment
  • Use of web services
  • Definition off services
  • Reference-Implementation
  • Documentation
Apr 2006 - Jun 2007
1 year 3 months
Germany

Senior Developer

Pelion XII AG

Expansion of the B2B shop of a tire wholesaler

  • Analysis, design, implementation and production of the largest web-based B2B shop for tires in Germany (reifen.com)
  • Implementation of front- and backend components as well as integration into inventory systems and third-party systems
Apr 2006 - Jun 2007
1 year 3 months
Germany

Senior developer/technical Project lead

SGH AG

Automated invoice verification of supplier invoices (Accounts receivable audit).

  • Definition of the target processes with the customer
  • Design and specification of process models and activity diagrams
  • J2EE design and implementation of a multi-tenant integration solution for automatic mass processing of commercial invoices at invoice receipt
  • Agile scrum based development
Aug 2004 - Mar 2006
1 year 8 months
Germany

Senior Developer

Pelion XII AG

Creation of a web app to carry out centralized settlement processes

  • Maintenance and further development (including quotation and sales support) of the multi-client solution for managing a bank's del credere business and for integrating del credere-relevant changes into the central settlement interface
  • Agile scrum based development
Jan 2003 - Jun 2003
6 months
Germany

Diploma student/diploma intern

I-CON GmbH

Preparation of the thesis

  • Title "Evaluation of EAI strategies and their prototypical implementation using IBM Websphere Portal Server"
Jan 2003 - Jun 2003
6 months
Germany

Working student/Technical project manager

I-CON GmbH

PoC for automatic credit monitoring in bulk business (overdraft facility/current account)

  • Analysis, design and implementation of a scoring system based on mass credit data from the GAD environment (BB3)
  • Early identification of credit risks in the current account portfolio
Jan 2003 - Jun 2003
6 months
Germany

Freelancer

Obi@Otto

Implementation of several IT projects

  • Agile planning and implementation of the intranet: technical management and project management
  • Planning and implementation of a mini-OLAP on web analysis: Requirements Engineering, design, analysis and implementation of a database-driven application to evaluate the user data of the then largest online store for do-it-yourself supplies on the German Internet
Jan 1999 - Dec 2004
4 years
Germany

Student

Leuphana Universität

Implementation of various student IT projects

  • Self-replicating, distributive, alternate programs via P2P (peer-to-peer)
  • Rating of real estate via scoring mechanisms
  • VIP Student "Email Call Center" - Inbound Marketing for Students
  • Internship in Datawarehouse/Catalog Marketing at Otto Versand
Jan 1998 - Jan 2002
3 years 1 month
Germany

Working student

ricardo.de

Implementation of several IT projects

  • Maintain multichannel database for auctions (CRM)
  • Create landinpages
  • Implement product features for core business (auction platform)
  • Implementation of a price calculator
  • Creation of a portal for reverse auctions

Summary

With a sound education in the economic environment and a degree in software engineering, I have worked for various companies, including banks, retail and e-commerce companies, companies from the automotive sector, medical companies and startups. My expertise lies in the successful implementation of software projects. I was part of a founding team of a successful startup that was later bought by Atlassian. In addition, as an IT consultant, I have accompanied projects with teams of different sizes from two to over 800 participants in different positions. These projects included app launches, further developments of banking applications in the foreign, treasury and securities sectors, migrations of core banking systems and the introduction of agile processes. Some of my projects were digital transformation projects. These included, for example, the establishment of a digital communication platform between independent federal authorities for the exchange of social security data, the re-establishment of an independent spin-off through the transformation of an investment banking financing product at a state bank and the comprehensive transformation of a previously undigitalized service provider that carries out billing for clinics and chief physicians. As part of my activities, products were developed that are used by millions of people. These include, among other things, components for online banking of one of the largest German financial service providers as well as services for the online purchase of tires or the purchase of Scandinavian residential design objects. In addition to the pure software engineering activities, I have also taken on project management, sub-project management and interim roles as a technical product owner.

Languages

German
Native
English
Advanced

Education

Oct 2001 - Jun 2004

Leuphana Universität (then Fachhochschule Nordostniedersachsen)

Diplom · Business Informatics · Germany

Oct 1998 - Jun 2001

Sparkassen

Sparkassen-Business-economist · Germany