Full-stack React Developer

5/2021 – 3/2022

PROJECT
A zoo of mortgage-related web apps and widgets

CLIENT
Germany's leading online marketplace for real estate

SKILLS
React, Redux, Router, TypeScript, TDD, Jest, Testing Library, Cypress, AEM CMS, Jenkins, S3, CloudWatch, AWS, Kanban

ACHIEVEMENTS & RESPONSIBILITIES
- Implemented and refactored React and Vanilla.js widgets on the most system-critical page of the client’s real estate platform with millions of daily visitors
- Introduced writing of automated tests with Jest and React Testing Library and directed the initiative to increase the code coverage with tests
- Eliminated the need to wait for the application to reload with a Storybook that allows the team to develop components in isolation
- Lifted several legacy projects to the latest 3rd-party library stack to make the projects more manageable for the team and reduce wasted time on context-switching
- Onboarded new team members and provided feedback on pull requests to maintain a high standard when it comes to code and test quality
- Coached project managers in creating and splitting User Stories according to INVEST criteria to ensure a smooth flow of continuous value delivery to the end-user

Amazon Web Services (AWS), CSS (Cascading Style Sheet), HTML5, JavaScript, Jenkins, Kanban (Softwareentwicklung), Node.Js, React (JavaScript library), React Native, Test Automation, Typescript

1/2021 – 4/2021

PROJECT
Carbon management SaaS platform

CLIENT
Leading provider of services to analyze, reduce & offset carbon emissions

SKILLS
React, Redux, Material UI, TypeScript, REST, Node, TDD, Jest, Testing Library, i18n, Docker, AWS, Scrum

ACHIEVEMENTS & RESPONSIBILITIES
- Introduced TDD with React Testing Library, resulting in an increase of the code coverage from 0 to 20%
- Navigated the initiative to introduce a centralized application state with Redux and its effects on unit tests
- Took ownership of complex releases to production

Scrum, Test Automation, Docker, Node.Js, Typescript, Amazon Web Services (AWS), JavaScript, React (JavaScript library), Representational State Transfer (REST)

4/2020 – 12/2020

PROJECT
SaaS platform to reduce gas and electricity bills

CLIENT
Germany's top online service to compare and switch utility providers

SKILLS
React, Redux, Saga, Router, Semantic UI, Flow Type, i18n, a11y, REST, Express, TDD, Jest, Testing Library, Cypress, Puppeteer, A/B Testing, Optimizely, Webpack, Docker, AWS, CodePipeline, Kanban

ACHIEVEMENTS & RESPONSIBILITIES
- Improved the provider change process UX by implementing frontend components with a clean architecture that separates presentation (React), central state (Redux), and asynchronous state transitions (Saga)
- Used a test-first approach to drive the implementation with acceptance, component, and unit tests; and shipped the app on a weekly basis using continuous delivery with CodePipeline and NPM
- Saved the company 3 developer months a year by improving the daily standup format
- Introduced TDD as well as Storybook and encouraged the team to develop components faster in isolation
- Eliminated 50,000 vulnerabilities in 3rd-party libraries with NPM and introduced Dependabot
- Tested new pages and component versions with A/B testing (Optimizely) to collect early user feedback

Continuous Delivery, Kanban (Softwareentwicklung), Test Automation, Docker, Node.Js, Typescript, Amazon Web Services (AWS), JavaScript, React (JavaScript library), Representational State Transfer (REST)

8/2018 – 3/2020

PROJECTS
- Responsive web app to rate and provide feedback about mortgage providers
- Dashboard to guide future homeowners from finding to financing properties
- Improved menu navigation for a large online marketplace
- dashboard to manage mortgages

CLIENT
Germany's leading online marketplace for real estate

SKILLS
React, Redux, Router, Thunk, Bootstrap, Recharts, JavaScript, jQuery, Node, REST, Swagger, Serverless, Lambda, DynamoDB, Express, Freemarker, AWS, Jenkins, TDD, Jest, Enzyme, Testing Library, Codecept, Protractor, Storybook, HTML, CSS, SCSS, SVG, Adobe AEM CMS, SauceLabs, Scrum, Kanban

ACHIEVEMENTS & RESPONSIBILITIES
- Enabled the client to increase the revenue per lead by categorizing leads into different quality tiers
- Implemented a responsive web application with purely functional React components and unidirectional data flow based on Redux and Thunks
- Developed a RESTful API with persistence and OpenAPI (Swagger) documentation based on the Serverless framework, AWS API Gateway, Lambda, and DynamoDB
- Drove the implementation with a test-first approach involving acceptance, system, integration & unit tests
- Automatically deployed app to test and production environments by defining continuous delivery pipelines with Jenkinsfiles, common steps with NPM scripts & infrastructure with CloudFormation declarations
- Created a React-, Redux- and Router-based web app with an onboarding wizard and dashboard to allow a major Dutch bank to gain insights into the buying behavior of potential mortgage customers
- Provided a serverless API proxy as the single point of contact for the app that integrated 2 external HTTP APIs and 5 internal REST APIs
- Redesigned the main navigation menu and supported the rollout to dozens of apps maintained by dozens of teams distributed over 3 locations and allowed a smooth transition via feature toggle
- Developed a responsive web application to gain insights into a user’s mortgage needs over time
- Helped client to get back in touch with past leads and significantly increased the customer lifetime value
- Developed a responsive dashboard with interactive custom pie, bar, and line charts using Recharts
- Paired with 3 other developers on vertically sliced User Stories using test-first programming

Kanban (Softwareentwicklung), Scrum, Test Automation, Jenkins, Node.Js, Amazon Web Services (AWS), CSS (Cascading Style Sheet), HTML, JavaScript, Jquery, React (JavaScript library), Representational State Transfer (REST), SVG (Scalable Vector Graphics)

5/2018 – 7/2018

PROJECT
Innovative web & mobile app for sharing project statuses

CLIENT
cultivate – Provider of IT training

SKILLS
React, Redux, Router, Bootstrap, HTML, CSS, Node, Serverless, REST, Swagger, MongoDB, AWS Cognito, TDD, Jest, Enzyme, eXtreme Programming

ACHIEVEMENTS & RESPONSIBILITIES
- Developed a MERRRN app based on React, Redux, Router, Express & MongoDB using a test-first approach
- Migrated a RESTful backend infrastructure based on Express and MongoDB into a serverless architecture utilizing AWS API Gateway, Lambda & DynamoDB

Mongodb, Extreme Programming, Test Automation, Amazon Web Services (AWS), CSS (Cascading Style Sheet), HTML, React (JavaScript library), Representational State Transfer (REST), Node.Js

1/2016 – 1/2017

PROJECT
Agile Software Engineering

CLIENT
Leading UK-based international daily financial newspaper

SKILLS
Scrum, Ceremonies Facilitation, Retros, User Stories, Backlog Refinement, Burn-up Charts, Trello, JIRA

ACHIEVEMENTS & RESPONSIBILITIES
- Increased the throughput by 50% by limiting the Work in Progress and introducing pair-programming sessions between juniors and seniors
- Introduced 3 teams to Scrum and facilitated ceremonies such as Retros, Reviews, and Daily Stand-ups
- Worked closely with Product Owners and Stakeholders and ensured a refined backlog

Scrum, Jira