Sebastian Hesse

ImmobilienScout24, Software Engineer

I'm supporting a product team developing SSO (Single Sign-On) and user messenger related features. The software is hosted on AWS using EC2/ECS, RDS, SQS, AWS Lambda, DynamoDB, etc. and main programming languages include Java, JavaScript and TypeScript.

Kurviger.de - Motorrad-Routenplaner, Software Engineer

Part-time project. The existing JavaScript and jQuery code was migrated to components using the Mithril framework. Additional serverless functions using Google Cloud Functions and Firebase were developed to support payment processes.

saas-marketplaces.com, Software Engineer

Built a collection of SaaS marketplaces to discover new opportunities starting a business. I was responsible for the technical architecture using a serverless stack.

• Serverless REST API using AWS Lambda and API Gateway
• Fully automated deployment process using AWS CloudFormation and GitHub Actions
• REST API documentation using OpenAPI (Swagger)

K15t GmbH, Software Engineer

My main responsibilities were developing new features and improving the existing code as well as the technical infrastructure on AWS.

• Designed and implemented several Java and Node.js serverless functions to automate synchronizing data between Jira systems
• Created a hybrid architecture using traditional EC2 servers and serverless functions for high scalability and high throughput of data
• Optimized page loading speed by adding Hazelcast cache for a Spring Boot REST API on EC2 instances
• Reduced security vulnerabilities in cooperation with a Bug Bounty program
• Improved infrastructure automation process by using AWS CloudFormation
• Increased app installations about 500% over two years

K15t GmbH, Software Engineer

Migrated an existing on-premise application to a serverless cloud application. I was responsible to plan and execute the migration. The code base was adjusted to run on-premise and in the cloud.

• Investigated existing architecture and code and proposed solutions to the product team using AWS Lambda
• Designed and prepared the migration by introducing a common code package to share code between the on-premise and cloud code
• Trained team mates in using the new cloud technologies like DynamoDB, S3, EC2 and AWS Lambda
• Introduced continuous integration process using Bitbucket Pipelines and infrastructure provisioning using AWS CloudFormation
• Reduced migration costs by adapting a hybrid architecture of EC2 instances and serverless functions

K15t GmbH, Software Engineer

My main responsibilities were developing new features, improving the existing code and writing automated tests.

• Developed backend and frontend features on Confluence apps "Scroll Versions" and "Scroll Translations" using Java and Angular
• Provided technical and first-level support
• Wrote technical and user documentation in Confluence

TravelTainment GmbH, Software Engineer

I was responsible for planning and developing an extension for an internal dashboard, including automated tests and technical documentation.

• Created a technical architecture using Apache Camel for retrieving and aggregating data from different data sources
• Communicated with various stakeholders to discuss their requirements and apply them in an agile process
• Implemented the backend part as an OSGi module for Apache Felix using Spring and the frontend part using jQuery

TravelTainment GmbH, Software Engineer

In a team of six people, I was responsible for developing various features for an internal dashboard service. This included writing automated tests and technical documentation.

• Communicated with various stakeholders to discuss their requirements and apply them in an agile process
• Implemented OSGi modules for Apache Felix using Spring to dynamically enable and disable parts of the internal dashboard
• Implemented a frontend using jQuery