Verified Expert in Engineering
Infrastructure Architecture Developer
Because Jan understands how important is delivering business values, he focuses on effective code delivery process. His own startup taught him, how to validate an idea, prototype and build MVP in a short period of time, as well as scale the product up. He also helps companies move to a cloud, building an infrastructure, automatizing and optimizing development processes, and passing this know-how to others. He loves to speak about CI/CD publicly.
Git, PhpStorm, Docker
The most amazing...
...thing I have ever built is a RADIUS server with the captive portal from scratch, allowing Wi-Fi authentication and authorization for tens of thousands of users.
Velvethy & Mikes Corporation
- Developed and directed hundreds of web applications.
- Transformed small regional based company into a strong European company with partners across the ocean.
- Introduced and involved the tools for project and company management.
- Led and educated the colleagues.
- Built a comprehensive cloud infrastructure.
- Introduced UUID as a replacement for integers ids and led database migration.
- Implemented Symfony/messenger component and used it for existing domain code.
- Detected and cleaned application from dead code.
- Upgraded PHP and composer packages to the latest versions.
- Dockerized project and automated deployment of containers.
Software Solutions Architect
- Migrated whole project to PSR-4 autoloading.
- Improved logging and monitoring, introduced and implemented Sentry error logging.
- Constantly took care of response times, profiled PHP code, solved bottlenecks, and improved performance.
- Created automated CI pipeline running tests and static analysis after each commit.
- Led team to cleaner architecture using well-proven design patterns. Introducing them to the team and implementing afterward.
Co-founder and CTO
- Communicated with the investors and successfully obtained an investment.
- Exhibited at Web Summit as an Alpha Startup.
- Completed an intensive training in Silicon Valley for startups.
- Completed a Grow with Google program and participated in many Google Launchpad for Developers events.
- Supported Czech PHP open-source community.
- Managed the whole cycle from an idea to a scaling product.
- Introduced and fully implemented CI/CD, completely automatizing deploys on 150+ projects.
- Designed enterprise projects' architecture and infrastructure.
- Communicated with crucial customers and directed their projects.
- Moved the entire company from Bitbucket to Gitlab (300+ repositories).
- Introduced regular weekly stand-ups to share know-how.
- Optimized code delivery process for front-end and back-end teams.
- Developed bunch of open-source packages.
- Acted as level 3 technical support.
- Developed an internal tool for cron jobs management and monitoring.
- Implemented Doctrine ORM to the team and replaced the active record pattern.
- Modernized existing PHP application introducing unit tests using PHPUnit and Composer.
- Took care of deploys.
Lead full-stack web developer
- Coded responsive HTML layouts.
- Lead junior fellow developers.
- Developed internal CRM software for keeping company data in the cloud.
- Maintained company codebase and infrastructure.
Full-stack web developer
- Coded HTML layouts.
- Communicated with clients and incorporated their requests and feedback.
- Created own framework using PHP + Smarty.
Full-stack web developer
- Acted as level 1 technical support.
- Was responsible for bug fixing.
- Coded HTML layouts.
Rector helps developers with refactoring and instant upgrades of their applications. It can do many things, few examples: update code to be compatible with the latest PHP version, detect dead code and remove it, improve code quality by applying clean code rules. It is used by thousands of PHP developers all around the world. Rector Github repository is regularly appearing in Github trendings projects.
As CTO I have ultimate responsibility for managing the IT team, guaranteeing to deliver business values in time and maintaining the infrastructure. I built the whole backend part by myself. The back end consists of more than 20 microservices. I created adapters for many third-party service providers (etc. invoicing, mailing, payment gateways) which can be connected by users. I am also publishing pieces of non-business code as open-source packages whenever possible. Technologies used include PHP (Nette Framework, Symfony, Slim), Python, MariaDB, MongoDB, SQLite, RabbitMQ, Memcached, and Docker.
I developed the back end (REST API) for Digital Queue with a focus on performance. The application is autoscaling and ready for huge peaks. Technologies used include PHP (Nette Framework, Symfony, Slim), MariaDB, MongoDB, RabbitMQ, and Docker.
Face Recognition Based Check-in
I was responsible for the whole project, including communication with the customer. I closely cooperated with frontend and QA teams. The backend part was built all by myself in PHP - OAuth2 server, REST API, data synchronization with Salesforce CRM. I set up the continuous deployment process to 3 different environments - dev, staging, and production. Technologies used include PHP (Nette Framework, Slim, Symfony), MySQL, and Redis.
AC Sparta Prahahttps://sparta.cz
I developed and implemented OAuth2 client for authenticating users with the Sparta iD single sign-on. I introduced CI and CD to the project allowing automated deploy to 3 different environments - dev, staging, and production. As well I was providing code reviews, helping to increase code quality and discover bugs. Technologies used include PHP (Nette Framework, Symfony), Elasticsearch, MySQL, and Docker.
Apple Museum Ticketing
Video Courses Platform - Eva Kiedroňová
I dockerized application, allowing more effective CI and deploy process. I handled testing and bug fixing and also developed new business intelligence features in the admin area for more effective business decisions. I helped with implementing A/B testing. Technologies used include PHP (Symfony), RabbitMQ, HTML, SASS, Node.js, and Docker.
I built for them a responsive website with fully manageable content via CMS. I also created an account opening form, which is connected to the Italian back-office, previously the only way to open an account in Directa Czech was to fill paper form. Technologies used include PHP (Nette Framework, Symfony), HTML, LESS, Bootstrap, jQuery, and Docker.
Real Estate Websites Component System
I created a set of private composer packages, that can be used independently to build a fully working website without a need for coding. All of the content is manageable through the admin module. The most interesting component I created is Pricelist component - it communicates with the ERP system and is capable of importing/exporting XML feeds or download them directly from the FTP. I emphasized reusability and extensibility. Technologies used include PHP (Symfony) Node.js, Webpack, and MySQL.
Ticketing Smart Contract
FX Mustang Automated Trading System
Nette, Symfony, Slim, Bootstrap, PHPUnit, Guzzle, Mockery, OAuth 2, Twig, JSON Web Tokens (JWT), Silex, Gearman, CakePHP, Laravel, React Native
jQuery, Doctrine, Salesforce API, Pipedrive API, REST APIs, SendGrid API, Dotenv, RADIUS, ReactPHP, Google APIs, Braintree API, PayPal API, MooTools, Node.js, React, Vue
Composer, Xdebug, Blackfire, Git, GitLab CI/CD, GitHub, GitLab, Sentry, PhpStorm, Postman, SendGrid, Phing, Docker Compose, Deployer, Adminer, PhpMyAdmin, Sequel Pro, Papertrail, Cron, RabbitMQ, Gulp, Grunt, Subversion (SVN), Braintree SDK, Sublime Text, MessageBird, Logging, Adobe Photoshop, NGINX, Let's Encrypt, Asana, Trello, Jira, Webpack, NPM, Ansible
Continuous Deployment, Continuous Integration (CI), Continuous Delivery (CD), DevOps, Clean Code, Test-driven Development (TDD), REST, Responsive Coding, Search Engine Optimization (SEO)
Docker, Linux, DigitalOcean, Google Cloud Platform (GCP), Mailgun, Heroku, Firebase, MacOS, iOS, MetaTrader 4, Ubuntu, New Relic, Apache2, WordPress, Kubernetes
MySQL, MariaDB, JSON, Database Migration, MongoDB, SQLite, NoSQL, Redis, Elasticsearch, Memcached, PostgreSQL, ClickHouse
SOLID Principles, Algorithmic Trading, Code Architecture, Domain-driven Design (DDD), Gaming, Domain DNS Setup, Profiling, Open Source, Infrastructure Architecture, Ajax, Single Sign-on (SSO), Monorepos, Message Queues, OAuth, Linux Server Administration, Entrepreneurship, IT Management, Public Speaking, Conference Speaking, Lecturing, SSL Configurations, CRM Systems, Ethereum Smart Contracts, Single-page Applications (SPA), Kubernetes Operations (kOps), Apache Benchmark, Performance Tuning, PHP Performance
Grow with Google for Startups
Startup with Google Academy
Go Global training, San Francisco
US Market Access Center
Developing Web Applications in Nette Framework