Sebastian Hesse

Decadia GmbH, Senior Software Engineer

I supported a Scrum team that's building a Serverless pension portal for a big energy corporation. It's a multi-tenant, event-driven system built on top of EventBridge, DynamoDB, S3 and AWS Lambda using TypeScript.

• Took a leading role in designing and implementing a custom architecture for authentication and authorization on top of Cognito
• Implemented a crucial feature for verifying and processing custom documents provided by users

Utoolity GmbH, AWS Consultant

Building libraries and code to extend the integrations between Atlassian products and AWS accounts.

• Developed a library to collect information about AWS resources and make them available via API
• Migrated multiple services from AWS SDK v2 and JavaScript to AWS SDK v3 and TypeScript

PACE Aerospace, Serverless Consultant

I advised two teams developing software for aircraft pilots about Serverless best practices on AWS.

• Improved the existing multi-tenant architecture for deployment processes, costs, and maintainability
• Automated their AWS Organizations setup
• Knowledge transfer about several AWS services like DynamoDB, Step Functions, and CI/CD tooling as well as AWS CDK

Anonymous Customer, Senior Software Engineer

I developed software using TypeScript & Java as well as infrastructure as code using Terraform & Terraform for CDK for a team which is responsible for a search product with several million visits per day. Lambda Functions perform Server-Side Rendering and must respond as fast as possible. In addition to that, a huge number of data is stored in several Elasticsearch (Amazon OpenSearch) clusters that are filled by different feeding systems. I supported the team re-architecting two of these feeding systems and building a 100% serverless, event-based system using several AWS services like AWS Lambda, MSK, S3, DynamoDB, StepFunctions, SNS, SQS and EventBridge.

ImmobilienScout24, Software Engineer

I have supported 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.

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.