Fredrik Teschke, Developer in Paderborn, North Rhine-Westphalia, Germany
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Fredrik Teschke

Verified Expert  in Engineering

Software Developer

Paderborn, North Rhine-Westphalia, Germany

Toptal member since June 5, 2020

Expertise
JavaJavaScriptVueReactDockerCSSSassSpringSwaggerMongoDBAgileKubernetesJenkinsExpress.jsRuby
Bio

Fredrik is a full-stack developer with a passion for the back end and an eye for the front end. A team player with a can-do attitude, he finds fulfillment in moving a feature from initial inception to production. Fredrik is experienced with projects ranging from small to large—from rapid development with Elixir in small teams to independent microservices and microfrontends that maintain a unified UX.

Portfolio

Team Engine
Elixir, Phoenix LiveView, Phoenix, DocuSign, Terraform, Alpine.js, CQRS
BogenGaudi
Netlify, GitLab CI/CD
Freelance
Vue, Spring

Experience

Java - 5 yearsJavaScript - 4 yearsVue - 3 yearsReact - 3 yearsSwagger - 3 yearsKubernetes - 3 yearsTypeScript - 2 yearsGitLab CI/CD - 2 years

Availability

Part-time

Preferred Environment

IntelliJ IDEA, Visual Studio Code (VS Code), Linux, Docker, Elixir

The most amazing...

...language I've worked with is Elixir—ideal for small, high-performing teams that want to quickly build a scalable product with a small tech stack.

Work Experience

Senior Full-stack Developer

2023 - PRESENT
Team Engine
  • Transitioned the legacy app to LiveView, eliminating JavaScript where possible and refactoring to a functional core or imperative shell architecture.
  • Added a new distribution feature to securely share sensitive files and messages.
  • Implemented a performant CSV export with a dynamic query builder UI.
Technologies: Elixir, Phoenix LiveView, Phoenix, DocuSign, Terraform, Alpine.js, CQRS

Co-owner and Full-stack Developer

2022 - PRESENT
BogenGaudi
  • Launched a sports rental company for Arrow Tag. We ship high-quality arrow tag equipment to all of Germany.
  • Built a Jamstack site and the booking process using GitLab CI/CD, Netlify, and AWS Lambda Functions.
  • Developed the business model, including shipping options, selected and purchased material, and set up the Google Ads campaign.
Technologies: Netlify, GitLab CI/CD

Software Developer

2019 - PRESENT
Freelance
  • Overhauled the core of a German accounting system for doctor's offices (dgpar GmbH). Increased maintainability of a complex legacy code. Improved DX and roundtrip times from Wildfly JEE monolith to event-based microservice architecture.
  • Extracted a Vue.js form library while adding developer tooling, including a form editor based on a JSON schema generated from TypeScript type definitions and an interactive storybook.
  • Implemented iWhistle, a whistleblowing platform based on the browser-side crypto using Ruby on Rails, Telekom OTC (deployed in Germany), and GitLab CI.
  • Added Mailchimp and Mandrill integration for transactional emails in a Ruby on Rails project.
  • Updated the integration of the payment services to ensure PSD2 compliance in a Ruby on Rails project.
Technologies: Vue, Spring

Software Developer

2017 - 2019
wescale
  • Merged many JavaScript libraries into a monorepo, easing development due to interdependencies.
  • Worked across the full stack of the back and front ends and the back end for front-end applications in the microfrontend environment.
  • Added new microservices and split existing ones to ensure small bounded contexts.
  • Wrote end-to-end tests on the REST API level to ensure a smooth transition during the refactoring of a major component.
Technologies: GitLab, React, Vue, TypeScript, Node.js, Java, Spring, MongoDB, Solr, Jenkins

Clickr | Student Response System for Schools

https://gitlab.com/clickr_app/clickr_server/
A student response system for schools designed to motivate.

The system enables teachers to give oral grades based on the response data rather than a gut feeling. Teachers also spend less time taking notes on student participation after or during each lesson.

For students, the system encourages engagement—enabling them to immediately see how their oral grade improves and continuously reflect on their participation.

Clickr | Student Response System

https://gitlab.com/clickr_app/clickr/
A Phoenix LiveView (Elixir)-based app that tracks in-class student participation via wireless Zigbee buttons. Its features include the following:

• A LiveView-powered live in-class dashboard.
• CQRS/ES using a commanded library.
• A Zigbee connector that pushes events from the classroom to the cloud app with a lightweight Elixir app on Raspberry Pi.
• Tailwind CSS and Alpine.js deployed to Fly.io with a GitLab CI/CD pipeline.
2013 - 2017

Master's Degree in IT Systems Engineering

Hasso Plattner Institute - Potsdam, Germany

2010 - 2013

Bachelor's Degree in Business IT

DHBW Mannheim - Mannheim, Germany

Libraries/APIs

Vue, React, Node.js, Vuex

Tools

Jenkins, GitLab CI/CD, IntelliJ IDEA, GitLab, Terraform, Solr

Languages

Java, JavaScript, Sass, Ruby, TypeScript, CSS, HTML, Kotlin, GraphQL, Elixir

Paradigms

REST, Agile, Functional Programming, Microservices, CQRS

Platforms

Docker, Kubernetes, Linux, Netlify, Visual Studio Code (VS Code)

Frameworks

Spring, Swagger, Redux, Express.js, Next.js, Micronaut, Spring Boot, Ruby on Rails (RoR), Phoenix, Alpine.js

Storage

MongoDB, PostgreSQL

Other

Gatsby, Architecture, Fly.io, Zigbee, Phoenix LiveView, DocuSign

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