Sebastian Hesse
Serverless Cloud Expert & Software Engineer

Summary
👨💻 I'm delivering high-quality software using modern cloud technologies like serverless functions on AWS Lambda. 🚀 I love automating processes and eliminating manual work. I'm offering you:
- advice on your serverless or cloud-native options,
- setting up a serverless or cloud-native architecture of your project,
- developing and further extending your existing serverless or cloud-native project,
- migrating existing applications into a serverless or cloud-native application.
Awards




Skills
AWS
3+ Years
AWS Lambda, EC2, DynamoDB, S3, IAM, CloudFormation
Atlassian
5+ Years
App & Plugin Development for Jira & Confluence, on-premise and in the cloud
Backend
8+ Years
Java, Maven, Spring, OSGi, Hibernate, JUnit, Node.js, MySQL, PostgreSQL
Frontend
6+ Years
HTML, CSS, JavaScript, Angular, Mithril, Bootstrap, jQuery
Experience
Freelancer
06/2019 - Present
Serverless Cloud Expert & Software Engineer
AWS
Serverless
Cloud
Software Engineering
Java
Node.js
JavaScript
Expert for serverless and cloud-native systems. Focusing on the software engineering part but also designing the architecture of cloud systems.
Karat
06/2019 - Present
Senior Interview Engineer (Freelance, part-time)
Technical Interview
Software Engineering Knowledge
Algorithms
Pair Programming
Karat is a company for making technical interviews fair and objective. I'm interviewing software engineering candidates for different technical roles on a freelance basis. Candidates are applying at top tech companies and I'm testing them for their software engineering knowledge, including algorithms. In the end, I'll provide feedback on the candidate's performance.
K15t
01/2018 - 09/2020
Software Engineer
AWS
Serverless
Cloud
Software Engineering
Java
Node.js
JavaScript
K15t is a company for developing apps for Atlassian products like Jira and Confluence. The main app I've worked on can synchronize issue data between Jira instances, on-premise and in the cloud. My main responsibilities were developing new features and improving the existing code + technical infrastructure.
K15t
07/2015 - 11/2017
Software Engineer (Working Student)
Software Engineering
Cloud
On-premise
Java
Node.js
JavaScript
Jira
Confluence
As a software engineer (working student), I developed features for multiple Atlassian Jira and Confluence apps, fixed bugs and wrote automated tests. I also migrated an on-premise app to a serverless cloud app.
TravelTainment (now Amadeus Leisure IT)
01/2014 - 07/2014
Junior Operations Internal Developer
Java
Spring
Hibernate
MySQL
Maven
OSGi
Apache Camel
jQuery
TravelTainment offers IT services for the travel industry. As a software developer, I developed an extension for an internal dashboard for tourism customers, including automated tests and technical documentation.
TravelTainment (now Amadeus Leisure IT)
09/2011 - 01/2014
Software Engineer (Apprenticeship)
Java
Spring
Hibernate
MySQL
Maven
OSGi
JUnit
Selenium
jQuery
Developed various internal software applications, like a dashboard system for internal reporting metrics, a mind map plugin for Redmine and smaller automation tools.
Projects
Full-Stack Web Development
10/2020 - Present
ImmobilienScout24, Software Engineer
AWS
EC2
RDS
DynamoDB
Serverless
AWS Lambda
CloudFormation
S3
SQS
SNS
Java
Spring
Spring Cloud
JUnit
JavaScript
TypeScript
AWS KMS
AWS SSM
Datadog
Kibana
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.
Frontend Migration & Serverless Development
06/2020 - 09/2020
Kurviger.de - Motorrad-Routenplaner, Software Engineer
JavaScript
jQuery
Mithril
Cypress
Serverless
Firebase Functions
Firebase
Google Cloud Functions
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.
Serverless REST API Development
04/2020 - 05/2020
saas-marketplaces.com, Software Engineer
AWS
Serverless
AWS Lambda
API Gateway
CloudFront
Route53
OpenAPI
Automation
GitHub Actions
REST API
Node.js
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)
Jira Plugin Development
01/2018 - 09/2020
K15t GmbH, Software Engineer
AWS
AWS Lambda
EC2
Kinesis
DynamoDB
S3
EC2
Step Functions
Cloud Watch
CloudFormation
Java
Maven
Spring
REST API
Jersey
Hazelcast
JUnit
Node.js
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
On-premise to Serverless Migration
04/2017 - 11/2017
K15t GmbH, Software Engineer
AWS
AWS Lambda
DynamoDB
Kinesis
S3
EC2
Cloud Watch
CloudFormation
Java
Maven
Spring
Spring Boot
REST API
Jersey
Node.js
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
Confluence Plugin Development
07/2015 - 03/2017
K15t GmbH, Software Engineer
Java
Maven
Spring
REST API
Jersey
OSGi
Angular
JavaScript
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
Internal Dashboard Extension
01/2014 - 07/2014
TravelTainment GmbH, Software Engineer
Java
Spring
Hibernate
Apache Camel
MySQL
Maven
OSGi
Apache Felix
JUnit
Selenium
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
Internal Dashboard
09/2012 - 01/2014
TravelTainment GmbH, Software Engineer
Java
Spring
Hibernate
MySQL
Maven
OSGi
Apache Felix
JUnit
Selenium
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
Publications
UXDX Conference 2019 in Dublin, Ireland
Discussed different experiences using serverless functions together with Nik (BBC) and Laura (Walmart). Shared best practices how to migrate and develop serverless functions as well as how maintenance and monitoring changed.
Atlas Camp 2019 in Vienna, Austria
Shared best practices for monitoring and analytics using serverless functions and services.
Talk: Going Serverless
04/2019
Atlassian Developer Day 2019 in Las Vegas, USA
Shared best practices and practical advice for successfully applying serverless functions in your project.
Talk: Caching in AWS Lambda
12/2018
AWS User Group Stuttgart 2018 in Stuttgart, Germany
Talked about different caching approaches when working with AWS Lambda and serverless functions.
Atlas Camp 2019 in Barcelona, Spain
Shared best practices and practical advice for successfully applying serverless functions in your project.
Education
University of Stuttgart
10/2014 - 11/2017
Master of Science in Software Engineering
Final Grade: 1.9
- Multitenant cloud architecture
- Distributed Systems
University of Applied Sciences Aachen
09/2011 - 07/2014
Bachelor of Science in Scientific Programming
Final Grade: 1.9
- Math
- Software Engineering