Stefan Trost, Developer in Stuttgart, Baden-Württemberg, Germany
Stefan is available for hire
Hire Stefan

Stefan Trost

Verified Expert  in Engineering

Front-end Developer

Stuttgart, Baden-Württemberg, Germany
Toptal Member Since
February 16, 2022

Stefan is a developer with 5+ years of commercial experience specializing in front-end and mobile development, conceptual design, planning, and prototyping. His technical expertise includes React, JavaScript, TypeScript, and Node.js. Stefan's industry experience is backed by a bachelor's degree in business informatics. A Certified Scrum Master, he is fascinated by technology and its possibilities and is highly motivated to leverage it to deliver customer and business value.


React Native, React, TypeScript, Ionic, Angular, WordPress, Balsamiq...
HubSpot, Google Cloud, Google BigQuery, Google Cloud Functions, APIs, SQL...
OpenAPI, Amazon Web Services (AWS), Firebase, TypeScript, React Native, Hasura...




Preferred Environment

MacOS, Visual Studio Code (VS Code), Git, Firebase, Google Cloud, JavaScript, TypeScript, React, React Native, Docker

The most amazing...

...project I've been involved in is planning, designing, and implementing a web and mobile application from the ground up for a startup.

Work Experience

Web Designer and Developer

2012 - PRESENT
  • Planned and developed an application where customers can subscribe to crowdfunded bus travel. I built the hybrid mobile application with JavaScript, Ionic Framework, Angular with a Node.js back-end, and Paypal SDK and Stripe API to process payments.
  • Designed and developed web pages with Adobe XD and WordPress.
  • Set up web hosting and administered web servers and MySQL databases.
Technologies: React Native, React, TypeScript, Ionic, Angular, WordPress, Balsamiq, Adobe Experience Design (XD), Prototyping, Front-end, Mobile App Development, Software Development, HTML, CSS, GitHub, Visual Studio Code (VS Code), Amazon Web Services (AWS), iOS, HubSpot CRM, Camera API, Google Cloud Functions, Back-end, Full-stack, HTML5, TypeScript 3, Python, Next.js

HubSpot and Google Cloud Data Integration Specialist

2024 - 2024
  • Developed and implemented a Google Cloud Function to automate data queries and processing, including setting up Service Accounts for secure connections.
  • Created and configured a private HubSpot application with authentication to enable API access and securely handle data.
  • Integrated and queried 15,000 entries from HubSpot based on specific parameters, including executing complex SQL queries with joins in Google BigQuery.
  • Developed an algorithm to process and analyze data, including matching, sorting, and filtering. Ensured efficient interim storage in CSV files for client review and finally writing the processed data back into HubSpot.
  • Deployment of the cloud function to the cloud, including comprehensive testing, debugging, and environment setup.
Technologies: HubSpot, Google Cloud, Google BigQuery, Google Cloud Functions, APIs, SQL, REST APIs, REST, Cloud, Authorization, Deployment

Technical Team Lead

2023 - 2023
  • Led and managed the development team, supporting junior developers and fostering a collaborative work environment.
  • Designed and implemented the architecture and functionality for an AI chatbot integrated with OpenAPI.
  • Developed a React Native app from scratch for event management and organization and successfully launched it on various app stores.
  • Implemented CI/CD pipelines and E2E testing to secure code quality and ensure continuous software delivery.
  • Interviewed, evaluated, onboarded, and trained new developers, ensuring they were quickly integrated into their roles and a fit for the organization.
  • Conducted regular code reviews to ensure software quality and adherence to best practices.
Technologies: OpenAPI, Amazon Web Services (AWS), Firebase, TypeScript, React Native, Hasura, Bitrise, CI/CD Pipelines, Architecture, Detox, E2E Testing, Scrum, Technical Recruiting, LangChain, Google Cloud Functions, Back-end, Node.js, Google Cloud Platform (GCP), Full-stack, Minimum Viable Product (MVP), HTML5, TypeScript 3

Senior Full-stack Developer

2022 - 2022
  • Developed a mobile application in React Native to create, invite, manage, and join certain events.
  • Refactored parts of the existing application to decrease code complexity and improve performance.
  • Implemented a JWT authentication flow for Firebase Authentication and Hasura.
  • Introduced a UI styling system with Storybook, RNUI, and Zeplin.
Technologies: React Native, GraphQL, TypeScript, Hasura, JavaScript, Storybook, PostgreSQL, AWS Lambda, Firebase, Auth0, Zeplin, REST APIs, ECMAScript (ES6), OpenAI GPT-3 API, OpenAI GPT-4 API, Android, iOS, Camera API, Google Cloud Functions, Back-end, Node.js, Google Cloud Platform (GCP), Full-stack, Minimum Viable Product (MVP), HTML5, TypeScript 3, Python

Front-end Developer

2022 - 2022
Aluma Technologies Ltd.
  • Developed a web application from scratch to manage and process intelligent document workflows.
  • Integrated PDFTron for previewing, annotating, editing, and navigating PDF documents.
  • Implemented a component library with Tailwind CSS.
  • Handled the implementation of automated unit and E2E tests using Jest, Testing Library, and Playwright.
Technologies: Svelte, JavaScript, TypeScript, Playwright, Jest, Storybook, PDFTron, PDF, Tailwind CSS, Minimum Viable Product (MVP), HTML5, TypeScript 3

Software Developer

2020 - 2021
  • Provided development and testing support for a hybrid React Native mobile application in the eHealth space. Refactored the old application and led the transition from JavaScript to TypeScript.
  • Developed and tested the React web application for this eHealth product.
  • Created the conceptual design and implemented the CI/CD pipeline.
Technologies: TypeScript, JavaScript, React, React Native, Docker, Jest, Git, Codeship, Bitbucket, REST, Xcode, Front-end, Mobile App Development, Software Development, HTML, CSS, Figma, GitHub, Scrum, Visual Studio Code (VS Code), REST APIs, ECMAScript (ES6), Android, iOS, Camera API, Google Cloud Functions, Full-stack, HTML5, TypeScript 3

Front-end Developer

2018 - 2020
Fraunhofer Institute for Manufacturing Engineering and Automation IPA
  • Continued development and support of a native Android app with Kotlin to support knowledge management.
  • Conceived, planned, and developed a web React application to support the production process and knowledge management.
  • Developed a React web application to visualize real-time data in a just-in-time way.
Technologies: React, Redux, OAuth, Git, Docker, Jenkins, REST, Android SDK, Kotlin, Front-end, Mobile App Development, HTML, CSS, React Native, Visual Studio Code (VS Code), iOS, Camera API, HTML5, TypeScript 3

Mymories | An App for Sharing Images Without Losing Data
A service to share images easily with multiple people at an event without losing data, such as a party, wedding, or holiday. Users can also display live images on a screen. I conceived, designed, and developed the idea from scratch, including the React Native application, the React web front end, and the back end hosted via google cloud functions.

Shuttle Up | An App for Crowdfunding Party Buses
A hybrid app to create and organize crowdfunded bus travels. I developed the app with the Ionic Framework in Angular on the front end, Firebase on the back end, and payment integration via Paypal SDK and Stripe to block and receive payments.

Personal Portfolio Page

A portfolio website with a responsive design optimized for user experience and SEO. Build with React and Next.js for server-side rendering of pages and powerful SEO and responsive TailwindCSS design, including light and dark modes.
2015 - 2018

Bachelor's Degree in Business Informatics

Furtwangen University - Furtwangen, Germany


Kubernetes for App Developers (LFD459)

The Linux Foundation


Certified Scrum Master

Scrum Alliance


React, REST APIs, Node.js, Stripe API, Stripe, Camera API, PayPal API, Playwright, OpenAPI


Git, Xcode, GitHub, Codeship, Bitbucket, Jenkins, Figma, Adobe Experience Design (XD), Cron, Balsamiq, PDFTron, Auth0, Zeplin


React Native, Redux, Jest, Tailwind CSS, Next.js, Android SDK, Angular, Ionic, Svelte, Detox


JavaScript, TypeScript, CSS, HTML, HTML5, TypeScript 3, SQL, ECMAScript (ES6), Java, C++, Kotlin, Bash, GraphQL, Python


REST, Mobile Development, Scrum, UX Design, E2E Testing


Visual Studio Code (VS Code), Firebase, Google Cloud Platform (GCP), Mobile, MacOS, Docker, WordPress, Amazon Web Services (AWS), iOS, HubSpot, Kubernetes, AWS Lambda, Vercel, Bitrise, Android


Google Cloud, Databases, Relational Databases, Backblaze B2, Hasura, PostgreSQL


Front-end, Mobile App Development, Software Development, API Integration, Full-stack, Minimum Viable Product (MVP), OAuth, GitHub Actions, Storybook, MERN Stack, APIs, Google Cloud Functions, Back-end, Google BigQuery, Cloud, Networking, Machine Learning, Data Analysis, Prototyping, Certified ScrumMaster (CSM), PDF, OpenAI GPT-3 API, OpenAI GPT-4 API, CI/CD Pipelines, Architecture, Technical Recruiting, LangChain, HubSpot CRM, Authorization, Deployment

Collaboration That Works

How to Work with Toptal

Toptal matches you directly with global industry experts from our network in hours—not weeks or months.


Share your needs

Discuss your requirements and refine your scope in a call with a Toptal domain expert.

Choose your talent

Get a short list of expertly matched talent within 24 hours to review, interview, and choose from.

Start your risk-free talent trial

Work with your chosen talent on a trial basis for up to two weeks. Pay only if you decide to hire them.

Top talent is in high demand.

Start hiring