Piotr is available for hire

Piotr Kuczynski

Verified Expert in Engineering

Software Developer

Berlin, Germany

Toptal member since February 19, 2016

Expertise

Full-stack Front-end Back-end Developers Cloud Architecture A/B Testing Interim CTOs Serverless JavaScript CSS HTML5

Bio

Piotr is a highly motivated, proactive, and ambitious software engineer with outstanding technical skills and over 20 years of experience. As an entrepreneurial professional and Agile evangelist, he has a strong personality and experience managing international and distributed teams. Piotr specializes in web development, performance optimization, and architecture design and is interested in usability and slick user interface designs.

Portfolio

Checkatrade

Node.js, TypeScript, TypeORM, Express.js, Fastify, PostgreSQL...

Engel & Völkers

TypeORM, TypeScript, PostgreSQL, SCSS, Kubernetes, React, Keycloak, Grafana...

Coperniq

React, Node.js, Express.js, MongoDB, TypeScript, Software Architecture...

Experience

JavaScript - 20 years
PostgreSQL - 10 years
Node.js - 8 years
React - 6 years
Google Cloud Platform (GCP) - 5 years
Amazon Web Services (AWS) - 4 years
Redux - 4 years
TypeScript - 1 year

Availability

Full-time

Preferred Environment

JavaScript, Node.js, React, TypeScript

The most amazing...

...thing I've built was a startup that grew to 50 employees and 20 million members in two years.

Work Experience

Lead Software Engineer

2024 - 2024

Checkatrade

Built back-end microservices, formulating the core platform for the new Checkatrade end-to-end offering.
Designed API standards and a set of REST and AsyncAPI.
Converted user stories into technical requirements.
Communicated with all stakeholders and legacy system owners.
Introduced shared types and SDK packages to speed up the cross-team development process, increase code re-usage, decrease code duplication, and improve overall quality.
Delivered beta and MVP apps on time despite ultra-tight deadlines.

Technologies: Node.js, TypeScript, TypeORM, Express.js, Fastify, PostgreSQL, Google Cloud Platform (GCP), Pub/Sub, GitHub Actions, Terraform, Helm, Firebase, OpenID Connect (OIDC), JSON Web Tokens (JWT), Docker, Jest, Datadog, GetStream, RDBMS, IT Project Management, Software Engineering, Google Cloud SQL, E2E Testing, ESLint, Prometheus, Winston, REST APIs, Google Pub/Sub, UML, Ubuntu, NPM, GitHub, OAuth 2, Architecture, Cloud Architecture, Scalability, Web Scalability, ECMAScript (ES6), CI/CD Pipelines, DevOps, Security

Senior Software Engineer

2020 - 2023

Engel & Völkers

Built a single-page application managing contracts and licensing fees.
Implemented continuous integration and continuous delivery processes using GitLab.
Built a REST API as Node.js, TypeScript, and PostgreSQL back end deployed with Docker to a Kubernetes cluster on GCP.
Hired new team members and supervised less experienced developers.
Converted business requirements into user stories and software architecture.

Technologies: TypeORM, TypeScript, PostgreSQL, SCSS, Kubernetes, React, Keycloak, Grafana, Koa, REST APIs, Terraform, Google Pub/Sub, Winston, Prometheus, SAP Business ByDesign, SAP, Mailgun, Sentry, Jest, Cypress, ESLint, Material UI, Formik, Redux, i18n, Yup, React-Intl, Webpack, E2E Testing, Docker, Google Cloud Platform (GCP), Google Cloud Storage, Google Cloud SQL, GitLab CI/CD, GitLab, Kanban, Scrum, Software Architecture, Cloud Architecture, B2B, Engineering, Architecture, Leadership, Full-stack, Agile, Requirements Analysis, Authentication, SDKs, Front-end Architecture, Front-end Design, Back-end Development, Web Security, LDAP, Helm, Pub/Sub, RDBMS, IT Project Management, Software Engineering, Ubuntu, NPM, OAuth 2, Playwright, React Testing Library, Web Scalability, ECMAScript (ES6), CI/CD Pipelines, DevOps, Security, Chrome DevTools

Software Architect

2020 - 2020

Coperniq

Advised on the software architecture for an MVP project management tool for solar engineering companies.
Provided consulting services on choosing appropriate technologies and tools.
Hired new engineers, built the team, and set up processes to deliver the project efficiently.

Technologies: React, Node.js, Express.js, MongoDB, TypeScript, Software Architecture, Project Consultancy, B2B, Engineering, Architecture, Leadership, Full-stack, Agile, Requirements Analysis, RDBMS, Software Engineering, REST APIs, GitHub, Security, Startups

Senior Software Engineer

2020 - 2020

InterJoin Ltd

Played a key role in InterJoin, a startup in the seed phase that was building an online platform to connect people interested in exchanging knowledge and services.
Built the MVP prototype rapidly from scratch based on the Zeplin designs.
Developed a single-page application in React using the Next.js framework, partially rendered statically and server-side for SEO optimization.
Constructed a Node.js back end in TypeScript for the app using MongoDB as a database.
Integrated a few open APIs for mocking parts of the profile, such as photos, to satisfy the MVP concept in the given limited time.
Created continuous deployment pipelines using Vercel.
Advised on UX and UI proposals from the designer who was part of the team.

Technologies: Vercel, MongoDB, Koa, Node.js, TypeScript, Next.js, Redux, React, Serverless, JavaScript, Full-stack Development, Front-end Development, Git, CSS, HTML, Front-end, Web Applications, APIs, User Experience (UX), User Interface (UI), Software Architecture, Project Consultancy, Cloud Architecture, Engineering, Architecture, Leadership, Full-stack, Agile, Requirements Analysis, Authentication, Front-end Architecture, Front-end Design, Back-end Development, RDBMS, Software Engineering, ESLint, Winston, REST APIs, Ubuntu, NPM, GitHub, OAuth 2, SSG, Server-side Rendering (SSR), Static Site Generators, Web Performance Optimization (WPO), ECMAScript (ES6), GraphQL, CI/CD Pipelines, Startups, Chrome DevTools

Lead Software Engineer

2020 - 2020

COMATCH

Contributed significantly to an online marketplace that connects companies of all sizes with independent business consultants and industry experts registered in their network for project-based work.
Built a microservice using TypeScript, which extracts and analyzes text from CVs exported from LinkedIn in PDF format and converts them to machine-readable JSON.
Established continuous integration processes using CircleCI.
Configured the deployment using AWS API Gateway and Lambda.
Led a small team of two back-end software engineers.

Technologies: AWS Lambda, Amazon API Gateway, Amazon S3 (AWS S3), Jest, Koa, Node.js, TypeScript, Serverless, JavaScript, Test-driven Development (TDD), Git, Unit Testing, APIs, Software Architecture, Engineering, Architecture, Leadership, Agile, Back-end Development, PDF, Software Engineering, E2E Testing, ESLint, REST APIs, Ubuntu, NPM, GitHub, OAuth 2, ECMAScript (ES6), CI/CD Pipelines, Security

Senior Software Engineer

2019 - 2020

Zalando Lounge Service

Worked on a Salesforce integration and a content management application for ordering content from agencies.
Developed various tools supporting marketing activities and data analytics for the marketing tech department.
Built a single-page application in React, with a Node.js, TypeScript, and PostgreSQL back end, to optimize the process of managing content orders from external agencies, such as product descriptions, landing pages, and SEO.
Integrated with the agency's 3rd-party APIs and exposed my own API as a webhook to receive agency process notifications.
Created a service for downloading analytical data daily from App Store Connect, converting it to CSV, and exposing it to the data analytics team in the S3 bucket.
Developed mass marketing emails using Salesforce Marketing Cloud.
Handled the deployments and infrastructure management in AWS with Kubernetes.

Technologies: Amazon Web Services (AWS), HTML5, CSS, HTML Email, JavaScript, Salesforce Marketing Cloud, Kubernetes, Docker, PostgreSQL, Node.js, TypeScript, React, Full-stack Development, eCommerce, Front-end Development, Git, HTML, Front-end, Web Applications, Unit Testing, User Experience (UX), User Interface (UI), Engineering, Full-stack, Agile, Back-end Development, Large-scale Projects, RDBMS, Software Engineering, ESLint, Winston, REST APIs, Salesforce, Ubuntu, NPM, GitHub, Gatsby, Puppeteer, Customer Relationship Management (CRM), SSG, Scalability, Search Engine Optimization (SEO), Server-side Rendering (SSR), Static Site Generators, Web Performance Optimization (WPO), Web Scalability, ECMAScript (ES6), GraphQL, CI/CD Pipelines, Chrome DevTools

Senior Software Engineer

2019 - 2019

Daimler Fleetboard

Worked on a platform for tracking the geopositioning and truck-trailer coupling status using a mobile app and physical sensors combined with data science algorithms.
Built a Node.js back end collecting data from various sources, including a mobile app, SOAP Listener, and Azure Event Hubs, persisting it to PostgreSQL and forwarding it to a data science platform.
Developed a single-page application in Angular 8, displaying the geopositioning and coupling status over the HERE Maps view.
Handled the deployments and infrastructure management in Azure DevOps and Azure with Kubernetes.

Technologies: Azure DevOps, Azure, Kubernetes, Docker, TypeORM, PostgreSQL, Koa, Node.js, TypeScript, RxJS, NgRx, Angular, JavaScript, Full-stack Development, SQL, Front-end Development, Git, CSS, HTML, Front-end, Web Applications, Unit Testing, APIs, User Interface (UI), Software Architecture, B2B, Engineering, Full-stack, Agile, Authentication, Front-end Architecture, Front-end Design, Back-end Development, Web Security, Maps, RDBMS, Software Engineering, E2E Testing, ESLint, Winston, REST APIs, Ubuntu, NPM, OAuth 2, ECMAScript (ES6), CI/CD Pipelines, Startups, Chrome DevTools

Front-end Lead

2018 - 2019

Körber Digital

Led a team of four front-end engineers working on an IoT product.
Built single-page applications in React that displayed analytical data for a production line and enabled operators to send feedback for machine speed losses.
Developed the back end in JavaScript-based serverless architecture on AWS.
Managed deployments and infrastructure in CircleCI and AWS or Azure.
Hired new team members, including front-end, back-end, and QA engineers.

Technologies: Amazon Web Services (AWS), Sentry, CircleCI, Azure, Enzyme, Mocha, Jest, Node.js, D3.js, Redux, React, Serverless, JavaScript, Test-driven Development (TDD), CTO, Front-end Development, Git, CSS, HTML, Front-end, Web Applications, Unit Testing, User Experience (UX), User Interface (UI), Software Architecture, Cloud Architecture, B2B, Engineering, Architecture, Leadership, Full-stack, Agile, Requirements Analysis, Authentication, SDKs, Front-end Architecture, Front-end Design, Web Security, RDBMS, Software Engineering, E2E Testing, i18n, ESLint, REST APIs, Ubuntu, NPM, GitHub, OAuth 2, Storybook, Serverless Architecture, WebSockets, SSG, Scalability, Server-side Rendering (SSR), Web Performance Optimization (WPO), Web Scalability, ECMAScript (ES6), Lazy Loading, Accessibility, CI/CD Pipelines, Security, Startups, Web Accessibility, Chrome DevTools

Senior Software Engineer

2017 - 2018

GoEuro (now Omio)

Contributed as part of the fast integrations department for GoEuro, a travel metasearch engine that allows users to compare the price and journey time of air, rail, and bus travel options in a single search.
Built end-to-end services offered to micro providers, covering search, routing, booking, ticket generation, and sales reporting.
Developed back-end services in Node.js, including search, routing, and booking, which I implemented in a microservice architecture and deployed to GCP using Kubernetes.
Implemented a PDF ticket-printing service as a server-side React app in Node.js.
Managed deployments and infrastructure in Kubernetes.

Technologies: Sentry, Kibana, Kubernetes, Docker, GIS, MongoDB, Protobuf, Node.js, React, JavaScript, SQL, Git, HTML, Unit Testing, APIs, Software Architecture, Engineering, Architecture, Agile, Requirements Analysis, SDKs, Back-end Development, PDF, Large-scale Projects, Web Security, Routing, Maps, RDBMS, Software Engineering, E2E Testing, ESLint, REST APIs, Ubuntu, NPM, GitHub, Travis CI, SSG, Scalability, Server-side Rendering (SSR), Web Scalability, ECMAScript (ES6), Caching, CI/CD Pipelines, Security, Startups

Senior Software Engineer

2017 - 2017

SatoshiPay

Built a drop-in web widget serving as a payment and content management client using React and Redux.
Migrated from Bitcoin to alternative cryptocurrency providers.
Implemented new cryptocurrency micropayment services.

Technologies: Cryptocurrency, IOTA, Stellar SDK, Bitcoin, Docker Cloud, Docker, Sinon.JS, Chai, Mocha, Karma, MongoDB, Node.js, Redux, React, JavaScript, Full-stack Development, Front-end Development, Git, CSS, HTML, Front-end, Web Applications, Unit Testing, Cryptography, User Interface (UI), eCommerce, Engineering, Full-stack, Agile, SDKs, Web Security, Software Engineering, E2E Testing, ESLint, REST APIs, NPM, GitHub, ECMAScript (ES6), Security, Startups, Chrome DevTools

Senior Software Engineer | Product Owner

2016 - 2017

Freelance

Served as a senior software engineer at SwapDoq and product owner at TravelMind Inc.
Built from scratch a prototype of a mobile web app based on React for sharing content-rich marketing brochures that include photos, videos, 3D objects, and animations.
Researched and designed a prototype of a next-generation travel management mobile app providing a seamless booking and time organization experience with a slick and simple user interface.

Technologies: SCSS, HTML5, React, JavaScript, Front-end Development, Git, CSS, HTML, Front-end, Web Applications, Unit Testing, User Interface (UI), User Experience (UX), Software Architecture, Project Consultancy, Engineering, Agile, Requirements Analysis, Front-end Architecture, Software Engineering, ESLint, NPM, GitHub, InVision, Certified Scrum Product Owner (CSPO), IT Project Management

Senior Software Engineer

2016 - 2017

Zalando

Developed Zalando's shop, the main front-end application customers use among many applications and services.
Built a React component library used across the company to quickly develop new features and maintain consistent UX/UI.
Applied refreshed UI designs for the main parts of the shopping application.

Technologies: Zeplin, Java, Jakarta Server Pages (JSP), Less, CSS3, HTML5, Sinon.JS, Enzyme, Chai, Mocha, Webpack, React, JavaScript, Test-driven Development (TDD), eCommerce, Front-end Development, Git, CSS, HTML, Front-end, Web Applications, Unit Testing, User Interface (UI), Engineering, Agile, Technical Writing, SDK Development, SDKs, Front-end Architecture, Front-end Design, Large-scale Projects, Software Engineering, ESLint, REST APIs, NPM, Scalability, Lazy Loading, Chrome DevTools

Senior Product Owner

2015 - 2016

Smartlaw (owned by Wolters Kluwer)

Developed new product ideas to increase the user base.
Refactored an existing functionality to increase conversions.
Implemented a notification system to bring people back to the site more often.
Redesigned and improved interactions for a better user experience and increased satisfaction.
Managed the backlog and prioritized features and bug fixes.

Technologies: Moqups, InVision, Jira, Web Applications, User Experience (UX), Software Development Management, Engineering, Agile Project Management, Agile, Front-end Design, Certified Scrum Product Owner (CSPO), IT Project Management, REST APIs, A/B Testing, Startups

Senior Front-end Software Engineer

2015 - 2015

smava

Developed a front-end application using Backbone.js.
Refactored existing code to achieve greater readability, testability, and performance.
Converted parts of the site to support responsive design.
Solved compatibility issues between browsers and platforms.

Technologies: Java, Sass, CSS3, HTML5, jQuery, Backbone.js, JavaScript, Front-end Development, Git, CSS, HTML, Front-end, Web Applications, Unit Testing, User Interface (UI), Engineering, Agile, Front-end Architecture, Front-end Design, Software Engineering, Search Engine Optimization (SEO), Chrome DevTools

Product Owner | Technical Lead – Izumi

2012 - 2015

Here Technologies (formerly a Nokia business)

Worked on Izumi, an internal crowdsourcing localization tool used by the HERE product family, moving the localization process into the continuous delivery world and shortening translation cycles from three weeks to a few minutes.
Defined the product scope and technical architecture.
Managed a small development team in Berlin, Germany, and Atlanta, USA.
Developed a full stack in Ruby on Rails with MySQL, HTML5, Sass, and JavaScript.
Introduced crowdsourced localization to the company.
Changed the localization process from a highly manual job to a fully automated process.
Shortened localization cycles from a few weeks to a few minutes.

Technologies: Amazon Web Services (AWS), Object-oriented JavaScript (OOJS), Kanban, Jira, Amazon Route 53, Amazon, Amazon EC2, Amazon CloudFront CDN, Redis, Amazon S3 (AWS S3), jQuery, Bootstrap, Sass, CSS3, HTML5, MySQL, Ruby on Rails (RoR), Ruby, JavaScript, Full-stack Development, SQL, Front-end Development, Git, CSS, HTML, Front-end, Web Applications, Unit Testing, APIs, User Experience (UX), User Interface (UI), Software Architecture, Software Development Management, Cloud Architecture, B2B, Engineering, People Management, Team Management, Agile Project Management, Architecture, Leadership, Agile, Requirements Analysis, Authentication, Technical Writing, SDK Development, SDKs, Front-end Architecture, Front-end Design, Back-end Development, Web Security, Certified Scrum Product Owner (CSPO), Lean Project Management, RDBMS, IT Project Management, Software Engineering, i18n, REST APIs, Startups, Chrome DevTools

Product Owner | Technical Lead – Dashboard

2011 - 2012

Here Technologies (formerly a Nokia business)

Developed the analytics dashboard displaying major KPIs for various Nokia products and services.
Handled product definition, design, and development.
Led the development and delivery team of three engineers.
Increased team engagement significantly and improved work quality and results by applying my expertise in product KPIs.

Technologies: Object-oriented JavaScript (OOJS), Kanban, Jira, jQuery, CSS3, HTML5, MySQL, Grails, JavaScript, Full-stack Development, Front-end Development, Git, CSS, HTML, Front-end, Web Applications, Unit Testing, User Experience (UX), User Interface (UI), Software Architecture, Software Development Management, Cloud Architecture, B2B, Engineering, People Management, Team Management, Agile Project Management, Architecture, Leadership, Agile, Requirements Analysis, Authentication, Front-end Architecture, Front-end Design, Back-end Development, Certified Scrum Product Owner (CSPO), Lean Project Management, RDBMS, IT Project Management, Software Engineering, REST APIs, Cucumber, Startups, Chrome DevTools

Senior Development Manager

2009 - 2012

Here Technologies (formerly a Nokia business)

Enhanced front-end performance by reducing the web page loading time from 30 to less than six seconds.
Improved cross-team cooperation by implementing continuous integration processes and running weekly tech talks, where developers could freely exchange knowledge.
Optimized the build system and overall release process—from every few months to only three weeks. Shortened the time from development to release by deploying it to production at the end of each sprint.
Increased Google indexing from thousands to millions of pages by designing and implementing an SEO strategy to boost presence on Google.
Mentored a web front-end development team of 28 developers.
Oversaw the overall Nokia Maps architecture for the web.
Led the integration with other Nokia and HERE services.
Worked on new product development and ideas with business owners and the UX team.

Technologies: Apache Tomcat, Jetty, Object-oriented JavaScript (OOJS), JUnit, Jasmine, JBehave, Selenium, Hudson, Nexus, Apache Maven, Java, CSS3, HTML5, CTO, Web Applications, Software Architecture, Software Development Management, Cloud Architecture, Engineering, Delivery Management, Engineering Management, People Management, Team Management, Agile Project Management, Architecture, Leadership, Full-stack, Agile, Requirements Analysis, Technical Writing, SDK Development, SDKs, Front-end Architecture, Large-scale Projects, Maps, Lean Project Management, IT Project Management, Software Engineering, i18n, REST APIs, Scalability, Web Performance Optimization (WPO), Web Scalability, A/B Testing, WebPageTest, Chrome DevTools

Development Manager

2007 - 2009

Wayn

Hired and managed a development team of 12 developers and three testers, helping build the Polish branch office's unique, friendly atmosphere.
Managed the workflow to maintain a dynamic development process, ensuring the website's quick growth.
Authored most of the website's core back-end mechanisms and provided expertise in database optimization.
Led the development process and wrote the most crucial part of the system.

Technologies: T-SQL (Transact-SQL), Microsoft SQL Server, Visual Basic 6 (VB6), CSS, JavaScript, HTML, SQL, CTO, Web Applications, User Experience (UX), Software Architecture, Software Development Management, Engineering, Engineering Management, People Management, Team Management, Agile Project Management, Architecture, Leadership, Full-stack, Agile, Requirements Analysis, Authentication, Front-end Architecture, Back-end Development, Large-scale Projects, Web Security, Lean Project Management, RDBMS, IT Project Management, Software Engineering, Mailgun, REST APIs, Scraping, Scalability, Search Engine Optimization (SEO), Web Performance Optimization (WPO), Web Scalability, Lazy Loading, Caching, A/B Testing, Security, Startups, WebPageTest

Director of Research and Development

2007 - 2009

Wayn

Solved the crucial performance issues of the website by clustering the back-end database.
Improved the core template processing mechanism, which sped up the development process.
Prepared the website for a multilingual interface.
Increased website traffic significantly by redesigning the website interface, which company members and the industry warmly welcomed.
Hired and led a development team of 16 developers and seven testers and an R&D team of two application architects and three graphic designers.
Mentored and helped individuals to achieve their goals.
Worked with partners on various product integrations, including global SIM cards, geolocation service, white labeling, branded credit cards, and hotel or restaurant booking.

Technologies: T-SQL (Transact-SQL), Microsoft SQL Server, Visual Basic 6 (VB6), CSS, JavaScript, HTML, CTO, SQL, Web Applications, User Experience (UX), Software Architecture, Software Development Management, Engineering, Delivery Management, Engineering Management, People Management, Team Management, Agile Project Management, Architecture, Leadership, Agile, Requirements Analysis, Authentication, Front-end Architecture, Front-end Design, Large-scale Projects, Web Security, Certified Scrum Product Owner (CSPO), Lean Project Management, RDBMS, IT Project Management, Software Engineering, Mailgun, REST APIs, Scalability, Search Engine Optimization (SEO), Web Performance Optimization (WPO), Web Scalability, Lazy Loading, Caching, A/B Testing, Security, Startups, WebPageTest

Owner | Network Administrator

2002 - 2007

HYPODE Networks

Started HYPODE Networks to provide part-time network administration services.
Built and managed a local computer network infrastructure.
Provided over 50 clients with internet access and services like email accounts and personal website hosting.

Technologies: Linux, Apache, LDAP

Senior Software Engineer | Team Leader

2005 - 2006

Mole Resourcing Ltd

Developed the website's first version based on business owners' specifications.
Built and managed a team of three developers and one graphic designer.
Managed the build, deployment, and testing processes.

Technologies: MySQL, PHP, JavaScript, CSS, HTML, Engineering, RDBMS, IT Project Management, Software Engineering, REST APIs, Startups

Senior Software Engineer

2004 - 2006

Wayn

Joined as one of the first two developers and was a co-author of the core website mechanisms.
Built the "invitation via contact import" mechanism, which allowed the website to grow from 45,000 to 1.5+ million members within six months and later maintain that growth.
Developed a web-based instant messenger, written using pure HTML and JavaScript—one of the first worldwide—working almost unchanged until today.

Technologies: T-SQL (Transact-SQL), Microsoft SQL Server, Visual Basic 6 (VB6), CSS, JavaScript, HTML, Full-stack Development, SQL, Front-end Development, Front-end, Web Applications, User Interface (UI), User Experience (UX), Software Architecture, Engineering, Architecture, Leadership, Full-stack, Agile, Authentication, Front-end Architecture, Front-end Design, Back-end Development, Large-scale Projects, Web Security, RDBMS, Software Engineering, Mailgun, REST APIs, Scraping, Scalability, Search Engine Optimization (SEO), Web Performance Optimization (WPO), Web Scalability, Lazy Loading, Caching, A/B Testing, Security, Startups, WebPageTest

Senior Software Engineer

2000 - 2005

Heuthes

Designed an advanced client-side template processing mechanism that separated the visualization layer from the data stream and business logic.
Built the solution using advanced JavaScript and Ajax and rendered it in browsers using XML and XSL. This improved the development process and application performance via better caching and decreased data transmission requirements.
Developed the web-based business management system using advanced JavaScript, HTML, and HDB, a scripting language invented internally by the company, written in Delphi and running on Windows and Linux.
Prepared technical documentation in Polish and English for the web-based banking products developed by the company Filia@Web and Virtual Info Banking.

Technologies: dBASE, PostgreSQL, Delphi, XPath, XSL, XML, CSS, JavaScript, HTML, Full-stack Development, SQL, Front-end Development, Front-end, Web Applications, APIs, User Interface (UI), User Experience (UX), Software Architecture, B2B, Engineering, Architecture, Full-stack, Authentication, Front-end Architecture, Front-end Design, Back-end Development, Web Security, RDBMS, Software Engineering, REST APIs, Security

Teacher

2003 - 2004

Maius College

Gave lectures and led laboratory classes on the subject of databases.
Taught relational databases and SQL language based on the PostgreSQL database system.
Engaged as a part-time teacher in the College of Economics and Information Technology while employed as a full-time teacher at Szczecin University of Technology.

Technologies: PostgreSQL, RDBMS, Pedagogy

Teacher

2000 - 2004

Szczecin University of Technology

Used the modern RDBM system to teach SQL, which required organizing a dedicated server running PostgreSQL for the students' databases.
Organized and led a group of students interested in software development. They participated in a contest for the best application written in Java for the Nokia Communicator 92xx platform organized by Borland Poland.
Introduced HTML and JavaScript classes in the Introduction to Computer Science course.
Taught first-year Computer Science studies to Bachelor of Science students before finishing my master's degree.

Technologies: Visual Basic for Applications (VBA), UML, PHP, JavaScript, HTML, PostgreSQL, SQL, RDBMS, Software Engineering, Pedagogy, REST APIs

Software Engineer | Blogger

1998 - 2002

Freelance

Developed the 2nd version of an application for Visuell Kommunikation AB in cooperation with the product manager from Sweden.
Fostered and maintained "Delphi in Questions & Answers"—the biggest Polish website at the time about Borland Delphi—as the creator and main contributor.
Served as the animator of the community associated with Delphi and internet newsgroups.

Technologies: CSS, HTML, dBASE, Delphi, Engineering, Desktop, Software Engineering, JavaScript, Windows API

Experience

InterJoin Ltd

A startup in the seed phase. It provides an online platform for connecting people interested in exchanging knowledge and services. I aimed to rapidly build the MVP prototype from scratch based on the Zeplin designs.

Zalando Lounge

An online outlet offering discounted fashion and lifestyle products in 17 European markets. I worked on a Salesforce integration and a content management application for ordering content from agencies. As part of the marketing tech department, I also developed various tools supporting marketing activities and data analytics.

Daimler Fleetboard

https://www.fleetboard.info

A logistics company developing tailored digital solutions to optimize logistics processes.

I worked on a platform that tracks the geopositioning and truck-trailer coupling status using a mobile app and physical sensors combined with data science algorithms. My responsibilities included building a back end in Node.js to collect data from various sources and a single-page application in Angular to display the data over the map view.

Körber Digital

https://www.koerber-digital.com

A spin-off from Körber AG that's focused on delivering IoT-based analytics for advanced production lines in multiple industries. I built a single-page application displaying live analytics for a production line and allowing operators to send feedback for machine speed losses.

GoEuro (now Omio)

A travel metasearch engine that allows users to compare the price and journey time of air, rail, and bus travel options in a single search. As part of the fast integrations department, I built end-to-end services offered to micro providers like small bus companies, covering search, routing, booking, ticket generation, and sales reporting.

SatoshiPay

https://www.satoshipay.io

A two-way payment platform that allows content providers to charge consumers a small fee as low as one satoshi or a fraction of a cent to read, watch, or listen to content. It also provides customers with a safe cryptocurrency wallet.

Zalando Shop

http://zalando.com

An eCommerce company maintaining a cross-platform online store that sells shoes, clothing, and other fashion items. I developed the shop's main front-end application for customers, applying refreshed UI designs for the main parts of the shop application.

Smava

https://www.smava.de

An online social lending platform that facilitates peer-to-peer lending services as well as loan comparison portal for Germany’s leading banks. Borrowers can obtain cheap online credit as a clever alternative to a bank loan with investors financing these loans directly.

Since its launch in 2007, more than 15,000 investors and 6,000 borrowers have done business with each other through the smava.de credit market, with loans totaling around €55 million in value.

SmartLaw

https://www.smartlaw.de

An online platform for generating customized legal documents in a few easy steps, backed by a strong lawyer's team and many 3rd-party law offices.

SmartLaw revolutionizes the creation of contracts and other legal documents. To deliver simple, cost-effective, and individualized documents, we combine the strengths of innovative software with expert lawyers and leaders in their fields. Each document is adapted to the user's personal needs, whether a large enterprise, small business, or private individual.

They work exclusively with top-ranked lawyers, and renowned communication designers have developed the platform's user interface and intuitive design. Data protection and security also fulfill the highest certification standards.

HERE Platform

https://www.here.com

A web companion for a localization platform. It combines highly accurate and fresh maps with cloud technology to enable rich, real-time location experiences. It is also a major competitor of Google Maps.

WAYN.com

A lifestyle-and-travel social network with 20 million members to help people discover where to go and what to do, meet like-minded people, and share aspirations and experiences. WAYN, which stands for Where Are You Now?, was referred to at the time as the "Myspace of travel."

ISOF ERP

http://www.isof.pl

A web-based company management system that covered multiple services, including sales, inventory, accountancy, payroll, customer relationship management, document management (DMS), eShop, logistics, eCommerce, and task management.

COMATCH (Malt)

An online marketplace that connects companies of all sizes with independent business consultants and industry experts registered in their network for project-based work. I built a microservice extracting data from a CV exported from LinkedIn.

Ruby Version Manager

https://rvm.io

A command-line tool that allows users to easily install, manage, and work with multiple Ruby environments, from interpreters to sets of gems. It supports several operating systems and all available Ruby interpreters and versions.

Faker.js

https://fakerjs.dev

A trendy library with over 2.5 million downloads weekly. It is used for generating massive amounts of fake but realistic data for testing and development. It was originally written in Perl, but ports to several languages exist. I worked on the JavaScript and TypeScript versions.

Ruby Configuration

https://github.com/rubyconfig/config

A widespread software library in Ruby to help developers manage environment-specific settings in an accessible and usable manner. It has over 23 million downloads and is based on YAML files with ERB syntax, inheritance, multiple environments, and support for common frameworks such as Rails, Padrino, or Sinatra.

Checkatrade Consumer App

A site that connects homeowners with approved local tradespeople. The site underwent a major shift toward end-to-end experience in a mobile app. I designed and led the implementation of the core back-end platform to deliver the new mobile experience.

Education

2003 - 2004

Postgraduate Degree in Pedagogy

Szczecin University of Technology - Szczecin, Poland

1996 - 2001

Master of Science Degree in Information Technology

Szczecin University of Technology - Szczecin, Poland

Certifications

JUNE 2014 - PRESENT

The Enterprise Lean Startup Survival Guide

Udemy

NOVEMBER 2013 - PRESENT

Certified Scrum Product Owner

Scrum Alliance

Skills

Libraries/APIs

jQuery, React, Node.js, React-Intl, Chai, REST APIs, Puppeteer, D3.js, Yup, Playwright, React Testing Library, Backbone.js, Windows API, Sinon.JS, NgRx, RxJS, Protobuf, Winston, Formik

Tools

NPM, Webpack, GitHub, Git, Jira, CircleCI, Travis CI, Sentry, GitLab CI/CD, GitLab, WebPageTest, Cucumber, Salesforce Marketing Cloud, Keycloak, Grafana, InVision, Moqups, Amazon CloudFront CDN, Apache Maven, Hudson, Jetty, Apache Tomcat, Apache, Mocha, Zeplin, Karma, Stellar SDK, GIS, Kibana, Terraform, Helm, Litmus

Languages

Object-oriented JavaScript (OOJS), HTML, CSS, Visual Basic 6 (VB6), XML, HTML5, CSS3, JavaScript, Sass, TypeScript, SCSS, SQL, Bash, ECMAScript (ES6), Ruby, T-SQL (Transact-SQL), GraphQL, Java, PHP, Delphi, dBASE, UML, Visual Basic for Applications (VBA), XSL, XPath, Less, C++

Frameworks

Next.js, Redux, Jest, Koa, Express.js, JSON Web Tokens (JWT), OAuth 2, Fastify, Ruby on Rails (RoR), Cypress, Material UI, Bootstrap, Grails, Selenium, JBehave, Jasmine, JUnit, Jakarta Server Pages (JSP), Angular

Paradigms

Serverless Architecture, Scrum, Kanban, Test-driven Development (TDD), Unit Testing, E2E Testing, B2B, Agile Project Management, Agile, Requirements Analysis, Search Engine Optimization (SEO), Web Performance Optimization (WPO), DevOps, Azure DevOps

Storage

MySQL, PostgreSQL, Google Cloud Storage, Google Cloud SQL, RDBMS, SQL Server Reporting Services (SSRS), Microsoft SQL Server, Amazon S3 (AWS S3), MongoDB, Redis, Docker Cloud, Datadog

Platforms

Amazon EC2, Amazon Web Services (AWS), Ubuntu, Linux, Docker, Kubernetes, AWS Lambda, Google Cloud Platform (GCP), Salesforce, Amazon, Nexus, Vercel, Azure, Mailgun, Desktop, Firebase, Blockchain

Other

Serverless, Scraping, Cloud Architecture, TypeORM, CSS Modules, Storybook, Full-stack Development, CTO, Front-end Development, Front-end, Web Applications, APIs, User Interface (UI), Google Pub/Sub, ESLint, i18n, IT Project Management, Software Architecture, Lean Project Management, Project Consultancy, Certified Scrum Product Owner (CSPO), Software Development Management, Engineering, Delivery Management, Engineering Management, People Management, Team Management, Architecture, Leadership, Full-stack, Authentication, SDK Development, SDKs, Front-end Architecture, Front-end Design, Back-end Development, Large-scale Projects, Pub/Sub, SSG, Scalability, Server-side Rendering (SSR), Static Site Generators, Web Scalability, Lazy Loading, Caching, CI/CD Pipelines, A/B Testing, Security, Startups, Chrome DevTools, Gatsby, LDAP, Amazon API Gateway, GitHub Actions, WebSockets, General Transit Feed Specification (GTFS), eCommerce, Cryptography, User Experience (UX), Pedagogy, Technical Writing, PDF, Web Security, Maps, Customer Relationship Management (CRM), Accessibility, Web Accessibility, Amazon Route 53, Enzyme, Bitcoin, IOTA, Cryptocurrency, HTML Email, Prometheus, SAP Business ByDesign, SAP, Software Engineering, Computer Science, OpenID Connect (OIDC), GetStream, OpenStreetMap, Routing, App Store Connect, Cryptocurrency Wallets

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