Publication
JavaScript Best Practices and Tips by Toptal Developers
https://www.toptal.com/developers/javascript/tips-and-practices
Johannes is available for hire
Hire JohannesJohannes Stein
Verified Expert in Engineering
Software Engineer and Developer
London, United Kingdom
Toptal member since June 30, 2014
Bio
Johannes is a highly skilled software engineer and manager who empowers autonomous teams to build a collaborative engineering culture. He has extensive knowledge of JavaScript, web technologies, and cross-platform development. Johannes is also extremely passionate about open-source software and is proficient in software architecture.
Portfolio
Nature's Menu
Vercel, Vercel Analytics, Next.js, Bun, TypeScript, Tailwind CSS, Storyblok...
FINDS
Mobile, Swift, Metabase, Kotlin, Agile Software Development, CTO, Leadership...
Mindful Chef
Agile Software Development, Scrum, Kanban, Ruby, TypeScript, React...
Experience
- JavaScript - 10 years
- Agile Software Development - 8 years
- React Native - 7 years
- Technical Leadership - 7 years
- React - 7 years
- Node.js - 6 years
- Engineering Management - 5 years
- TypeScript - 4 years
Preferred Environment
Visual Studio Code (VS Code), GitHub
The most amazing...
...code I've written was to solve a complicated linking problem on my own for which no answer was available through Google.
Work Experience
Head Of Engineering (D2C)
2023 - 2026
Nature's Menu
- Orchestrated the implementation of a headless eCommerce storefront with a focus on performance and experimentation, and introduced AI-powered tooling into development workflows.
- Championed the rebuild of the subscription checkout experience with a focus on conversion rate, experimentation, and data-driven decision making.
- Steered the move from a developer-heavy CRM solution to a self-serve platform for non-technical users, reducing turnaround time on average from 8.5 days to 1.5 days.
- Recruited, managed, and empowered an in-house cross-functional software engineering team moving away from agency-supported projects. This was essential to reduce the engineering budget by 40% while building out a collaborative engineering culture.
Technologies: Vercel, Vercel Analytics, Next.js, Bun, TypeScript, Tailwind CSS, Storyblok, Amazon Web Services (AWS), Google Analytics 4 (GA4), Google Tag Manager, React, Cursor AI, A/B Testing, Team Leadership, Remote Team Leadership, Figma, REST, GraphQL, Agile Software Development, Engineering Management, REST APIs, Kanban, Code Review, Software Architecture
Chief Technology Officer
2023 - 2023
FINDS
- Worked as a part of the senior leadership team to transform a tech-enabled company into a tech-driven company.
- Advocated for data consistency and data-driven decision-making.
- Initiated, planned, and tracked the development of the Android port of the flagship iOS app.
Technologies: Mobile, Swift, Metabase, Kotlin, Agile Software Development, CTO, Leadership, Amazon Web Services (AWS), Android, iOS, Figma, App Store, REST APIs, Team Leadership, Mobile Development, Git, Third-party APIs, REST, Front-end, NestJS, Code Review, Software Architecture
Head of Engineering
2021 - 2023
Mindful Chef
- Decreased cycle time by 40% by transforming the approach from "work for squads" into building "squads around work."
- Built, maintained, and guided the engineering vision for the next three years.
- Transitioned from a hybrid working environment into a remote-first culture.
- Introduced, managed, and mentored engineering managers within the digital department.
Technologies: Agile Software Development, Scrum, Kanban, Ruby, TypeScript, React, React Native, Ruby on Rails (RoR), Engineering Management, Heroku, Budget Management, Next.js, Leadership, Figma, App Store, REST APIs, Team Leadership, Mobile Development, Git, Third-party APIs, REST, Front-end, Code Review, Software Architecture, Scalable Architecture
Front-end Technical Lead
2021 - 2021
Mindful Chef
- Built a collaborative engineering culture by empowering autonomous teams and advocating for bottom-up approaches.
- Grew the front-end engineering team from 6 to 17 developers within six months.
- Enabled the transformation from disciple-based teams into cross-functional squads.
Technologies: Agile Software Development, TypeScript, JavaScript, React, React Native, Redux, Scrum, Kanban, Engineering Management, Technical Leadership, HTML, CSS, Styled-components, Heroku, Next.js, Leadership, Architecture, Figma, App Store, REST APIs, HTML5, Team Leadership, Mobile Development, Git, Third-party APIs, REST, Front-end, Code Review, Software Architecture, Scalable Architecture
Technical Lead
2020 - 2021
Gamesys Group
- Empowered the transformation of moving to TypeScript and React Hooks.
- Played an integral part in adopting a design system for all front-end web concerns across the company.
- Provided a framework and process to empower developers to suggest technical improvements and tech health items.
Technologies: React, Flux, Node.js, Material UI, TypeScript, JavaScript, Koa, Technical Leadership, HTML, CSS, Sass, Leadership, Architecture, REST APIs, HTML5, Git, REST, GraphQL, Front-end, Code Review, Software Architecture, Scalable Architecture
Principal Developer and Team Lead
2018 - 2019
Gamesys Group
- Co-organized internal Innovation Days to experiment with new ideas and approaches for the front-end platform.
- Streamlined repeatable and reliable hiring and onboarding processes, coordinating with internal recruiters and involving and upskilling developers.
- Advocated and introduced microfrontends across multiple teams as a means to de-couple development, technology choices, and releases.
Technologies: Agile Software Development, Kanban, Engineering Management, Technical Leadership, JavaScript, Flux, Node.js, HTML, CSS, Sass, Architecture, Leadership, REST APIs, HTML5, Team Leadership, Git, REST, Front-end, Code Review, Software Architecture, Scalable Architecture
Senior Front-end Developer
2017 - 2018
Gamesys Group
- Drove the technical delivery of two greenfield projects with two different offshore teams.
- Led the refactoring of the legacy build system to a modern alternative.
- Introduced technical talks, bringing multiple teams together to share ideas and new patterns.
Technologies: JavaScript, Flux, React, Node.js, Webpack, HTML, CSS, Sass, Redux, REST APIs, HTML5, Git, REST, Front-end, Code Review, Software Architecture, Scalable Architecture
Developer
2016 - 2017
Playabl
- Built out the deltaDNA analytics React Native module as an open-source.
- Set up a continuous integration environment with work-in-progress automatically published internally to stakeholders and shareholders.
- Sped up the process from wireframe to implementation and improved the collaboration between designers and developers by introducing Sketch and Zeplin workflows.
Technologies: React Native, JavaScript, Flow, Sketch, Zeplin, Node.js, Express.js, Redux, App Store, Mobile Development, Git, Third-party APIs, Front-end, Code Review, Software Architecture
Software Engineer
2015 - 2016
Binary Thumb
- Built out continuous integration with CircleCI and created easy-to-use build and deployment processes to integrate with Amazon EC2.
- Migrated the back-end CoffeeScript codebase to ECMAScript 2015+.
- Discovered and experimented with effective ways of communication between on-site and remote employees.
Technologies: React, Node.js, JavaScript, UI Design, Amazon Web Services (AWS), Amazon DynamoDB, CoffeeScript, Hapi.js, Full-stack, APIs, App Store, REST APIs, HTML, HTML5, Git, REST, Front-end, Code Review, Software Architecture
User Experience Developer
2014 - 2015
Geniux Consulting GmbH
- Developed small-scale products for several clients.
- Focused on applications that run on mobile devices or have a touch component.
- Oversaw DevOps tasks, such as continuous integration with Jenkins and creating easy-to-use build and deployment processes.
Technologies: Meteor, React, JavaScript, Node.js, CSS, HTML, React Native, Jira, GitLab, Jenkins, Full-stack, HTML5, Unity3D, C++, C#, Mobile Development, Git, Front-end, Code Review
Software Engineer
2012 - 2014
CostXpert AG
- Handled and provided most of the front and back end as the lead software architect.
- Empowered other team members to contribute toward the open-source software we were using by creating processes and best practices for contributing to GitHub.
- Defined and implemented a build pipeline based on Grunt, which processes, optimizes, and delivers client-side assets such as JavaScript files, images, and fonts.
- Introduced and shaped Learning Fridays, where the morning was spent on internal talks showcasing learnings from working on the product, the latest developments in the JavaScript ecosystem, and industry best practices.
Technologies: CouchDB, Node.js, JavaScript, jQuery, CSS, Bootstrap, Express.js, HTML, Full-stack, APIs, REST APIs, HTML5, Git, REST, Front-end, Code Review, Software Architecture, Scalable Architecture
Mobile Game Developer
2011 - 2012
retroteam UG
- Created the initial iOS version using the Sparrow framework.
- Implemented and adopted a cross-platform web version to simplify development across multiple platforms.
- Set up analytics to capture core gameplay metrics.
Technologies: iOS, JavaScript, jQuery, Mobile Development, Front-end
Software Engineer
2011 - 2011
Acomba UG (Self-employed)
- Created an initial prototype of their flagship product for iOS platforms using Objective-C and Cocoa Touch.
- Provided documentation and best practices for turning the prototype into a published app.
- Provided installers for different platforms to simplify the installation with the flagship macOS product.
Technologies: Objective-C, iOS, Dropbox API, Mobile Development, Front-end
Experience
GocciaScript (ECMAScript Interpreter)
https://github.com/frostney/GocciaScriptA subset of ECMAScript 2026+ implemented in FreePascal - It's based on the thought "What if we implement ECMAScript today, but without the quirks of early ECMAScript implementations". Features that are error-prone, redundant, or security risks are intentionally excluded.
Sparrow iOS Game Framework Beginner's Guide
Sparrow is a game framework focused on ease of use and current state-of-the-art technologies. The framework is intended for 2D games and multimedia applications and has built-in support for touch, animation, and managing objects on the screen.
The book, Sparrow iOS Game Framework Beginner's Guide, aims to teach a complete overview of how to develop a mobile game for iOS using Objective-C and Sparrow. Instead of teaching concepts separately, this book takes a methodical approach, taking readers through the development of an entire game using Sparrow's powerful framework.
The book, Sparrow iOS Game Framework Beginner's Guide, aims to teach a complete overview of how to develop a mobile game for iOS using Objective-C and Sparrow. Instead of teaching concepts separately, this book takes a methodical approach, taking readers through the development of an entire game using Sparrow's powerful framework.
Irrlicht 1.7 Realtime 3D Engine Beginner's Guide
The Irrlicht Engine is a cross-platform, high-performance real-time 3D engine written in C++. It features a powerful high-level API for creating complete 3D and 2D applications such as games or scientific visualizations.
The book, Irrlicht 1.7 Realtime 3D Engine Beginner's Guide, teaches how to master all that is required to create 2D and 3D applications using Irrlicht, from installation to deployment. It is a step-by-step guide to Irrlicht that starts at an easy level for beginners. It then gradually works to more advanced topics through clear code examples and demos illustrating theoretical concepts.
Starting with installation, the book guides readers through creating a basic template application, followed by meshes, overlays, and UI. Readers will then scan through data types, nodes, scenes, cameras, lights, and particle systems. Finally, readers will learn about some advanced concepts, such as handling data, files, and shaders, followed by the last stage: deployment.
The book, Irrlicht 1.7 Realtime 3D Engine Beginner's Guide, teaches how to master all that is required to create 2D and 3D applications using Irrlicht, from installation to deployment. It is a step-by-step guide to Irrlicht that starts at an easy level for beginners. It then gradually works to more advanced topics through clear code examples and demos illustrating theoretical concepts.
Starting with installation, the book guides readers through creating a basic template application, followed by meshes, overlays, and UI. Readers will then scan through data types, nodes, scenes, cameras, lights, and particle systems. Finally, readers will learn about some advanced concepts, such as handling data, files, and shaders, followed by the last stage: deployment.
React Amsterdam: React for Game Development
http://youtu.be/JaK-RrYPPRkThis is a talk I gave at the React Amsterdam conference in April 2016. React Amsterdam is an international conference for React developers. Please note that the slides are a bit delayed in the video linked to this project.
Publication
React.js Best Practices and Tips by Toptal Developers
https://www.toptal.com/developers/react/tips-and-practices
Publication
React Native Beginners Tutorial—A Cold Dive
https://www.toptal.com/developers/react-native/cold-dive-into-react-native-a-beginners-tutorial
Publication
The Duel: React Native vs. Cordova
https://www.toptal.com/developers/app/comparing-react-native-to-cordova
Skills
Libraries/APIs
React, Node.js, jQuery, REST APIs, jQuery UI, Dropbox API
Tools
GitHub, Webpack, WebStorm, Figma, Git, Flow, Sketch, Zeplin, Jira, GitLab, Jenkins
Languages
JavaScript, CoffeeScript, CSS, TypeScript, HTML, HTML5, Swift, Objective-C, Sass, Ruby, C++, Kotlin, C#, GraphQL, ECMAScript (ES6), Delphi
Frameworks
React Native, Next.js, Bootstrap, Express.js, Ruby on Rails (RoR), Redux, Flux, Material UI, Koa, Hapi.js, Unity3D, NestJS, Tailwind CSS
Paradigms
Mobile Development, Agile Software Development, REST, Scrum, Kanban, UI Design
Platforms
iOS, Meteor, Android, Amazon Web Services (AWS), Heroku, Visual Studio Code (VS Code), Mobile, Vercel, Storyblok
Storage
CouchDB, Amazon DynamoDB
Other
Technical Leadership, Team Leadership, Front-end, Code Review, Engineering Management, Full-stack, App Store, Third-party APIs, Software Architecture, Scalable Architecture, Styled-components, Budget Management, Metabase, CTO, Leadership, Architecture, APIs, Vercel Analytics, Bun, Google Analytics 4 (GA4), Google Tag Manager, Cursor AI, A/B Testing, Remote Team Leadership
Collaboration That Works
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