Dennis Kühn
Verified Expert in Engineering
Back-end Developer
Berlin, Germany
Toptal member since July 26, 2021
Dennis is a software engineer with more than 15 years of experience, primarily in back-end development with an expert grasp of Java and related technologies. However, Dennis's work is not limited to any specific technology. Whatever tech the project requires, you can trust that his code will be well structured and scalable, thoroughly tested, and generally be well implemented. Dennis is passionate about creating sustainable, simple, and elegant solutions.
Portfolio
Experience
- Java - 15 years
- Software Development - 15 years
- Distributed Systems - 15 years
- Spring - 10 years
- Spring Security - 10 years
- REST - 10 years
- Microservices - 8 years
- Python - 3 years
Availability
Preferred Environment
MacOS, IntelliJ IDEA
The most amazing...
...task I've worked on so far was creating a compiler for porting a legacy C codebase to Java.
Work Experience
Full-stack Developer
A Logistics Company (Self-employed)
- Created a tool for managing contact information related to communication channels.
- Connected with the business experts to find the most usable solution.
- Developed a persistence solution that supports relational access to heterogeneous data structures.
- Coached and mentored a junior developer to help them further their career.
Software Engineer
A Musical Instrument Manufacturer (Self-employed)
- Designed and implemented a distributed embedded system with real-time requirements.
- Developed drivers for various peripheral modules, e.g., sensors, actuators, display, and so on.
- Designed and created a high-throughput binary protocol.
- Supported the company regarding digital transformation, software, hardware, and process-related topics.
Software Engineer
Equal Experts (Self-employed)
- Created a microservice-based research tool for a client in the music industry which required close cooperation with the domain experts, front-end development, and back-end development.
- Implemented a migration tool based on complex domain logic.
- Established the development, staging, and production infrastructure.
Lead Developer (2017-2019) | Senior Java Engineer (2012-2017)
eBay | Brands4Friends
- Managed a cross-functional development team that included back-end engineers, front-end engineers, and QA experts.
- Implemented business requirements for eCommerce applications (a web shop, REST API, and so on) with a focus on robustness, maintainability, and security.
- Designed and implemented a solution for integrating payment methods in a generic way. This included fine-grained tracking and monitoring of payment processes.
- Worked continuously on the optimization of the technical platform and the development process, such as the transition from biweekly releases to continuous delivery.
- Developed an authentication microservice supporting multiple access levels and federated OAuth2 login.
- Created a microservice for inventory management with interfaces to ERP systems and marketplace APIs.
Senior Java Developer
GameDuell
- Worked on the game server—implementing various single and multi-player games.
- Created a compiler for porting a legacy C codebase to Java.
- Implemented an algorithm for the distribution of profits.
Senior Software Engineer
Mediaworx Berlin AG
- Developed multitenant web applications for a market leader in the tourism industry with configuration-based feature sets and layouts.
- Implemented web services and web service clients (SOAP, REST).
- Evaluated technologies for the company's service portfolio.
Experience
Brands4Friends
As a lead developer, I was responsible for areas such as identity, payment services, and inventory management. Throughout my engagement, I contributed to modernizing the software design and architecture. Together with the operations team, I helped the company transition from a traditional release process to continuous delivery.
Education
Diplom-Ingenieur (Master Equivalent) Degree in Media Computer Science
Hochschule der Medien - Stuttgart, Germany
Certifications
AWS Certified Cloud Practitioner
Amazon Web Services
Oracle Certified Professional, Java SE6 Programmer
Oracle
Skills
Libraries/APIs
JAX-RS
Tools
IntelliJ IDEA, Apache Solr, Grafana, JavaCC, Helm
Languages
Java, Python, C, JavaScript, SQL, TypeScript, Embedded C++
Frameworks
Spring, Spring Security, JPA, OAuth 2, Apache Struts, Hibernate, Spring Boot, Angular
Paradigms
REST, Microservices, DevOps
Storage
Spring Data, MySQL, Redis, Elasticsearch, PostgreSQL, Oracle RDBMS
Platforms
MacOS, Docker, Kubernetes, Amazon Web Services (AWS), AVR (8-bit MCU), OpenShift
Other
Software Development, Payment APIs, Distributed Systems, Web Security, Operating Systems, Networks, Embedded Tomcat, Java Native Interface (JNI), GlassFish, RS485, I2C, Serial Peripheral Interface (SPI), MIDI, Saleae, Prometheus, Enterprise Java Beans (EJB)
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