Sebastian Hesse

Serverless Cloud Expert & Software Engineer

profile-pic

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

Badge Badge Badge Badge

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.

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.

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
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.

Kurviger.de - Motorrad-Routenplaner, Software Engineer
JavaScript
jQuery
Mithril
Cypress
Serverless
Firebase Functions
Firebase
Google Cloud Functions

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

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
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
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
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.

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