Janusz is available for hire
Hire JanuszJanusz Paśkiewicz
Verified Expert in Engineering
Software Developer
Rzeszow, Poland
Toptal member since February 13, 2019
Bio
Janusz is a lead Magento 2 developer and solution architect with 20 years of experience in eCommerce and an Adobe Certified Expert in Adobe Commerce. He helped build the G2A.com marketplace on Magento 1, migrated busy stores from Magento 1 to 2 without stopping sales, and delivered B2B platforms with headless (Venia) and Hyvä storefronts integrated with ERP, PIM, and marketplaces. He now adds AI features to Magento stores and works hands-on with merchants from scope to go-live.
Portfolio
Self-employed
Magento 2, Adobe Commerce, Hyva Themes, PHP 8, MySQL, Redis, Varnish...
Spyrosoft
Magento 2, PWA, Headless Commerce, GraphQL API, AI Integration
Sintra Consulting Poland
Magento Enterprise, Magento Extension Development...
Experience
- Magento - 18 years
- eCommerce - 18 years
- MySQL - 15 years
- PHP 7 - 15 years
- JavaScript - 8 years
- Magento 2 - 7 years
- Claude - 2 years
- Shopify - 1 year
Work Experience
Lead Magento 2 Developer | Solution Architect
2026 - PRESENT
Self-employed
- Supported, upgraded, secured, and sped up Magento 2, Adobe Commerce, and Mage-OS stores for mid-market merchants in the UK, EU, and North America as the single accountable senior developer, on fixed-price phases and monthly retainers.
- Delivered Magento 2.4.x and PHP 8 upgrades and security patching, tested on staging and released in short maintenance windows, with performance measured before and after.
- Built and migrated storefronts on Hyvä and headless PWA Studio (Venia), and moved a retailer taking hundreds of orders a day from Magento 1 to Magento 2 while it kept trading.
- Built two-way ERP, PIM, and marketplace integrations on REST, GraphQL, and RabbitMQ queues, with monitoring, and B2B features such as company accounts and customer-specific pricing.
- Integrated Claude and OpenAI APIs into Magento stores to generate product descriptions, translations, and SEO data for thousands of SKUs, with human review where it matters.
- Advised merchants on staying on Magento versus moving to Shopify with fixed-price audits covering three-year cost, feature gaps, migration risk, and SEO.
Technologies: Magento 2, Adobe Commerce, Hyva Themes, PHP 8, MySQL, Redis, Varnish, Elasticsearch, RabbitMQ, GraphQL API, REST APIs, Docker, Shopify, AI Integration, Claude
Lead Magento Developer
2024 - 2025
Spyrosoft
- Led the transformation of multiple Magento stores into a unified platform, covering B2B functionality and a headless setup using Magento Venia (PWA storefront).
- Handled the integration with two custom ERP systems, covering bidirectional data synchronization (products, pricing, inventory, orders).
- Contributed to the integration with Ergonode PIM and BaseLinker, enabling centralized product management and multi-channel order fulfillment.
Technologies: Magento 2, PWA, Headless Commerce, GraphQL API, AI Integration
Magento 2 Developer | eCommerce CTO
2019 - 2024
Sintra Consulting Poland
- Led Magento 2 delivery for an eCommerce agency for five years as solution architect and hands-on technical lead, reviewing and shipping code across multiple client projects.
- Built integrations, troubleshot production issues on live client stores, and ran performance work on Magento 2 backends, from caching and indexers to database queries.
- Grew the team's technical skill set and drove the adoption of new technologies and solutions, mentoring developers while staying hands-on in the codebase.
- Acted as eCommerce CTO: made architecture decisions on client projects and supported project delivery from scoping to go-live.
Technologies: Magento Enterprise, Magento Extension Development, Object-oriented Programming (OOP), Back-end, SQL, Full-stack, Plugins, MySQLdb, Performance Tuning, User Experience (UX), Google Search Console, Magento, Shopify
Senior Magento Developer | Team Leader
2014 - 2019
G2A.com
- Led the Magento software development team with scrum methodology.
- Created many different features, mainly involving the Magento back-end.
- Contributed to many integrations with microservices around Magento.
- Supported G2A whenever necessary, as it is a jam-packed website, so there were many performance challenges to overcome.
Technologies: RabbitMQ, Apache Solr, Node.js, MongoDB, MySQL, PHP 7, Laravel, APIs, JavaScript, New Relic, NGINX, Git, REST APIs, Object-oriented Programming (OOP), Back-end, SQL, Vue, Full-stack, Plugins, MySQLdb, Performance Tuning, Google Search Console, Magento
Senior PHP Developer
2010 - 2014
PGS Software
- Worked for a software house as a PHP web developer, working closely with various clients.
- Migrated a client's shopping cart based on an old OXID engine to an entirely new OXID engine, which involved porting many custom modules.
- Provided long-term support of a CRM system. This system was created with a custom PHP framework, so creating many new features and fixing existing bugs was necessary.
- Worked using PHP Frameworks like Zend and Symfony.
- Upgraded WordPress CMS website to its newest version, preparing layout including all CSS custom changes to match the received design.
Technologies: OXID, Symfony, Zend Framework, jQuery, JavaScript, CSS, HTML, MySQL, PHP, WordPress, PHP 5, HTML5, REST APIs, Back-end, CakePHP, SQL, Full-stack, Plugins, MySQLdb, Performance Tuning, Moodle, User Experience (UX), Google Search Console, Magento
Technical Architect | Lead Developer
2008 - 2010
Blueclaw
- Led and managed various projects, mostly custom eCommerce engines.
- Created solutions from scratch and modify existing websites and eCommerce solutions.
- Architected with Magento 0.8 Beta.
- Ensured that the projects met high SEO standards as this was a mainly SEO company.
Technologies: osCommerce, X-Cart, jQuery, JavaScript, MySQL, PHP, SEO Tools, Search Engine Optimization (SEO), CubeCart, Object-oriented Programming (OOP), Back-end, SQL, Full-stack, MySQLdb, Performance Tuning, SEO Audits, Image Optimization, User Experience (UX), Magento
Java and Delphi Programmer
2006 - 2007
Comarch
- Contributed to the build of a data warehouse for a big insurance company.
- Programmed in Delphi and Java. Developing custom software to manage the data warehouse.
- Created Oracle packages and procedures in PL and SQL.
- Identified and resolved bugs or errors reported by the client in the current release of the program.
Technologies: PL/SQL, Oracle, Delphi, Java, Object-oriented Programming (OOP), Performance Tuning
Project History
Magento 1 to Magento 2 Migration Without Stopping Sales (alena-firany.pl)
https://alena-firany.plMigrated alena-firany.pl, a busy Polish curtain and drapery retailer taking hundreds of orders a day, from Magento 1.9 to Magento 2.4 as a solo freelancer. The scope covered a new hosting server, migration of a catalogue of ready-made and by-the-metre products, customers, orders, and SEO (URLs and redirects), replacement or customization of third-party modules, and a tested cut-over. The store kept trading throughout the migration.
Unified B2B Platform with a Headless Venia Storefront for a Major Bicycle and Motorcycle Brand
Consolidated the Magento 2 stores of a major Polish bicycle and motorcycle brand into a single B2B platform with a headless PWA Studio (Venia) storefront, as lead Magento developer at Spyrosoft. Integrated two ERP systems for two-way synchronization of products, prices, stock, and orders, and connected the Ergonode PIM and BaseLinker for centralized product management and multi-channel order fulfillment. Owned the architecture, led a small development team, and delivered the B2B functionality on top of the unified catalogue.
G2A.com Website
I created many features on G2A.com as a Magento 1 full-stack developer during my 5-year full-time position there. For example, I worked as the lead developer who implemented the option of selling electronics in the marketplace.
Maintenance of Magento Websites
I developed several improvements and bug fixes for a family of websites that I was maintaining in 2011-2012:
• https://viviscal.com
• https://viviscal.co.uk
• https://viviscal.es
• https://viviscal.pt
• https://viviscal.com
• https://viviscal.co.uk
• https://viviscal.es
• https://viviscal.pt
Portal for Lottery Games Fans
https://www.multipasko.plIn 2004, I created a portal for enthusiastic fans of Polish lottery games. Over time, the portal became this category's most popular independent website. It has about 100,000+ visits daily, and 10+ million page views monthly.
I am still the portal's owner, developer, and admin.
I am still the portal's owner, developer, and admin.
Education
2001 - 2006
Master's Degree in Computer Engineering
Politechnika Rzeszowska - Rzeszów, Poland
Certifications
AUGUST 2020 - PRESENT
Adobe Certified Expert - Adobe Commerce Developer
Adobe
AUGUST 2020 - PRESENT
Adobe Certified Professional — Adobe Commerce Developer
Adobe
Skills
Libraries/APIs
jQuery, REST APIs, Shopify API, GraphQL API, Node.js, Vue
Tools
Magento Modules, Claude Code, Claude, NGINX, PhpStorm, CubeCart, Jira, Git, RabbitMQ, Apache Solr, Moodle, Varnish, GitHub
Languages
PHP, HTML, PHP 5, HTML5, PHP 7, SQL, PHP 8, JavaScript, CSS, Java, Delphi
Paradigms
Object-oriented Programming (OOP), Search Engine Optimization (SEO)
Platforms
New Relic, Magento 1, Magento 2, Magento Extension Development, Magento API, Shopify, Adobe Commerce, Magento, Magento Enterprise, Linux, Docker, X-Cart, osCommerce, Oracle, WordPress
Storage
MySQL, MySQLdb, MongoDB, Redis, PL/SQL, Elasticsearch, PostgreSQL
Frameworks
Laravel, Symfony, CakePHP, Zend Framework
Other
Web Development, eCommerce, Back-end, Full-stack, Plugins, Google Search Console, APIs, Websites, Data Structures, Web Scraping, Performance Tuning, PWA, Headless Commerce, SEO Audits, Image Optimization, User Experience (UX), Hyva Themes, Data Migration, OXID, Computer Engineering, Leadership Development, SEO Tools, AI Integration, Enterprise Resource Planning (ERP)
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