Clemens Helm
Verified Expert in Engineering
Software Developer
Vienna, Austria
Toptal member since October 24, 2017
Clemens has been working as a full-stack web developer for about two decades. He's passionate about designing and building high-quality products. What he loves most about freelancing is the opportunity to encounter various types of projects, people, and cultures. Working this way, he constantly gains experience and knowledge for his next projects.
Portfolio
Experience
- JavaScript - 20 years
- SQL - 20 years
- Ruby on Rails (RoR) - 16 years
- Ruby - 16 years
- Test-driven Development (TDD) - 12 years
- Amazon Web Services (AWS) - 4 years
- Meteor - 3 years
- React - 2 years
Availability
Preferred Environment
Git, Zsh, ITerm, Vim Text Editor, MacOS, Visual Studio Code (VS Code)
The most amazing...
...platform I've built is Codeship, a continuous integration service for developers.
Work Experience
Senior Full-stack Developer
Goody
- Improved an eCommerce platform for sending and receiving gifts with Ruby on Rails and React.
- Implemented interfaces to third-party eCommerce providers.
- Created solid and fast-performing user interfaces with React and Tailwind CSS.
- Implemented advanced search functionality using triggers and search vectors with PostgreSQL.
Freelance Web Application Developer
Clemens Helm
- Developed solid corporate websites with PHP, JavaScript, and CSS.
- Helped early-stage startups with their software architecture by developing an MVP and mentoring junior developers.
- Created features for legacy Ruby on Rails codebases and cleaned them up by introducing test-driven development followed by an extensive refactoring.
- Implemented data imports from Twitter, Instagram, and other APIs.
- Processed images with ImageMagick to enhance certain aspects like their dominant color—in a way like Instagram filters.
Founder
DevCraft Academy
- Created extensive web development training for junior developers.
- Built a high-performance e-learning platform with Ruby on Rails, Turbo, and Stimulus.
- Mentored junior developers to accomplish their next career step quickly.
- Implemented multi-repository continuous deployment to deploy changes in under three minutes.
CTO
Medbee
- Managed a small team of web, iOS, and Android developers.
- Transitioned the outdated front end to a modern stack using Webpack, TypeScript, and React.
- Improved the overall architecture while simultaneously reducing overall complexity and improving reliability.
- Created a GraphQL API on top of Ruby on Rails to give front-end developers the flexibility to fetch the data they need.
- Ensured everyone on the team was happy and productive.
- Handled numerous other tasks, like planning sprints, reviewing pull requests, communicating with stakeholders, etc.
Lead Full-stack Developer
Temedica
- Developed a mobile app for a community of people using a certain medical product.
- Led a small team of web developers working with Vue.js and Ruby on Rails.
- Coordinated communication with several stakeholders within Temedica as well as from external clients.
Senior Front-end Developer
PSPDFKit
- Improved the PSPDFKit web viewer, a toolkit to render and annotate PDF documents in the browser.
- Developed examples of usage scenarios for the PSPDFKit web viewer to demonstrate use cases.
- Wrote guides to showcase features of the web viewer.
Senior Full-stack Developer
IOHK
- Got introduced to developing smart contracts on a blockchain.
- Developed an electron application that manages sandboxed Node.js processes.
- Collaborated with an international team of developers.
CEO | CTO
ChillBill
- Created a web platform for automated accounting using Meteor, MongoDB, and React.
- Developed a robust invoice recognition software using Ruby, ImageMagick, and Tesseract.
- Led a team of nine brilliant web developers and data scientists.
- Created a strong product vision and planned the product features according to the vision and customer feedback.
- Used several APIs for reliable currency conversion, safe vat number validation, and others.
IT Consultant | Mentor
Inselberg
- Advised a team of founders about technology stacks and product strategies.
- Mentored junior developer on how to develop a solid Ruby on Rails app.
- Implemented critical features which required a senior developer.
- Reviewed code to ensure code quality and performance.
- Provided my product team with feedback on their roadmap.
Full-stack Developer
Sientia
- Created a reliable business workflow web application for real-estate companies.
- Refactored the existing code to make it as maintainable as possible.
- Gained a lot of experience with MongoDB indexing and deployment on a database of a few terabytes.
- Worked on a huge Ruby on Rails app with hundreds of thousands of lines of code.
- Developed a sophisticated full-text search with Elasticsearch and gained experience in deploying it.
Vice President of Engineering
Codeship
- Developed a hosted continuous integration platform using Ruby on Rails, PostgreSQL, and LXC.
- Led a team of several brilliant software developers.
- Participated in the TechStars Boston program with the Codeship team.
- Managed and developed the front and back end of the entire Codeship web application.
- Developed an exhaustive testing suite to ensure the reliability and expandability of the platform.
Experience
Codeship
https://codeship.com/ChillBill
Medbee
https://medbee.org/I led the tech team as CTO and coordinated development on a wide range of technologies, like Ruby on Rails, React, GraphQL, and Android and iOS native development. I also actively developed in the web front end and back end.
Education
Master's Degree (in Progress) in Software Engineering and Internet Computing
The Vienna University of Technology | TU Wien - Vienna, Austria
Master's Degree (in Progress) in Media and Computer Science
The Vienna University of Technology | TU Wien - Vienna, Austria
Master's Degree (Spent a Semester Abroad) in Computer Engineering
Faculdade de Engenharia da Universidade do Porto - Porto, Portugal
Bachelor's Degree in Media and Computer Science
The Vienna University of Technology | TU Wien - Vienna, Austria
Skills
Libraries/APIs
React, Node.js, jQuery, MobX, Vue, Vuex, Mongoid, Marionette.js, ImageMagick
Tools
Cucumber, Codeship, Amazon Elastic Container Service (ECS), Git, Atom, Vim Text Editor, Webpack, Middleman, RabbitMQ, Apache Solr, Zsh, Amazon Elastic Container Registry (ECR), AWS SDK, ITerm, Turbo
Languages
JavaScript, Ruby, HTML, SQL, CSS, Sass, HTML5, TypeScript, Elixir, GraphQL, Swift
Paradigms
Test-driven Development (TDD), Behavior-driven Development (BDD), Object-oriented Programming (OOP), Unit Testing, Testing, Software Testing, Continuous Delivery (CD), Continuous Development (CD), Agile, Functional Programming, Continuous Integration (CI), Scrum
Platforms
Meteor, Heroku, Amazon Web Services (AWS), MacOS, Amazon EC2, Docker, Visual Studio Code (VS Code)
Frameworks
Electron, Ruby on Rails (RoR), Material UI, Express.js, React Native, Tailwind CSS, Ruby on Rails 7, Stimulus
Storage
Amazon S3 (AWS S3), Redis, MongoDB, PostgreSQL, Databases, Memcached, JSON
Other
Semantic UI, Full-stack, Web Development, APIs, Product Management, Tesseract, Usability, Storybook, Software Engineering, Computer Science, Computer Engineering, Image Processing, Lean Product Development, Product Development, Infrastructure as Code (IaC), Mentorship & Coaching, Bootstrap 5, OAuth
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