Johannes E.
Senior Software Engineer
Experience
Aug 2021 - Apr 2022
9 monthsLondon, United Kingdom
Senior Software Engineer
Deliveroo
- Role undertaken on a freelance basis.
- Geo-Sharding different ruby services.
- Planned and executed a project to allow the company to process more orders at peak time by launching a second amazon aurora database cluster and offloading high-volume tables with billions of rows to the new cluster.
- Successfully decreased absolute CPU usage during peak hours on average by 15.79%.
- Skills: Ruby on Rails, AWS, Kafka, Microservice Architectures, BigData, Terraform, Datadog, Protocol Buffers.
Jan 2021 - Jul 2021
7 monthsSan Francisco, United States
Senior Software Engineer
Monograph
- Role undertaken on a freelance basis.
- Consulting the engineering team on system architecture and best practices around development workflows and processes.
- Mentoring teammembers and building features in Ruby on Rails.
- Skills: Ruby on Rails, GraphQL.
Jul 2019 - Jun 2020
1 yearBerlin, Germany
Team Lead Growth Engineering
Tourlane
- Led the Growth Engineering team (seven Engineers, one Product Manager) responsible for building customer-facing web applications for lead generation and ad-tech products.
- Led an initiative to extract SEO pages into a serverless microservice using Gatsby, resulting in a 3x performance improvement for website interaction time.
- Skills: Ruby on Rails, AWS, Kafka, Microservice Architectures, Ad Tech, A/B Testing, Docker, Snowflake, Terraform.
Sep 2018 - Jun 2019
10 monthsBerlin, Germany
Senior Software Engineer
Tourlane
- Built a tracking infrastructure using Apache Kafka.
- Introduced a last-click attribution model and created marketing reports, leading to data-driven marketing decisions company-wide.
- Calculated target cost per acquisition for paid marketing (based on historical data) to increase SEM ad efficiency.
Oct 2016 - May 2017
8 monthsSan Francisco, United States
Lead Developer
Airgora
- Developed technology and led product iterations from the first prototype to release, achieving product-market fit.
- Skills: Ruby on Rails, React.js.
Nov 2014 - Dec 2016
2 years 2 monthsBerlin, Germany
Co-Founder & CEO
99trips
- Co-founded a TravelTech startup offering a one-stop shopping experience for technology-based curated city trips, achieving 10k+ registered users and 10k+ € sales.
- Developed technology and managed a team of five people.
- Skills: AngularJS, Ruby on Rails, AWS.
Dec 2012 - Present
12 years 9 monthsAddis Ababa, Ethiopia
Co-Founder & Board Member
NGO KAJO e.V.
- Co-founded the association (over 30 members) and raised over 50k € in donations for education in Ethiopia.
- Organized and executed projects on site in Addis Ababa, Ethiopia.
Open Source Contributor
ViewComponent
- Contributed to the open-source framework ViewComponent (initially built by Github).
- The framework adds functionality for building reusable, testable, and encapsulated view components in Ruby on Rails.
Languages
German
NativeEnglish
AdvancedSpanish
AdvancedEducation
Sep 2011 - Aug 2014
University of Applied Sciences HTW Berlin
Bachelor of Science, Web Technologies · International Media and Computing · Berlin, Germany
Certifications & licenses
Certified ScrumMaster
Scrum Alliance
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