Alexander is available for hire

Alexander Kamiński

Verified Expert in Engineering

Full-stack Developer

Location

Warsaw, Poland

Toptal Member Since

January 14, 2018

Alexander believes that the method and pattern implemented are crucial, more so than the language and framework used, so he's comfortable with switching technologies often. In his 15 years of professional experience, he's worked on web projects, games, and tools in the most popular programming languages. Alexander particularly relishes challenges and thrives in the most unorthodox projects.

Full-stack Front-end Ruby on Rails (RoR)Ruby Regex PostgreSQL Node.js React Redux Integration Distributed Systems Code Review Ruby Performance Linux Shell Design Pattern OAuth 2.0

Portfolio

+SUBSCRIBE®

Ruby on Rails (RoR), JavaScript, Node.js, React, PostgreSQL, Makefile, Docker...

Freelance

JavaScript, TypeScript, Tailwind CSS, Redux, Alpine.js, Node.js, React...

SameSystem

React, Redux, Ruby on Rails (RoR), GraphQL, Apollo, Node.js, Full-stack...

Experience

JavaScript - 13 years PostgreSQL - 10 years Distributed Systems - 8 years React - 4 years Python - 4 years TypeScript - 3 years Elixir - 2 years Phoenix - 1 year

Availability

Part-time

Preferred Environment

Emacs, Linux, MacOS, TypeScript, Full-stack

The most amazing...

...thing I've ever designed and built was an MQ-backed offer processor for the biggest Polish real-estate company.

Work Experience

Senior Full Stack Developer for an Enterprise Platform Solution

2022 - 2023

+SUBSCRIBE®

Led a multi-month effort to update the company's complex front-end library setup from React 16 to 18, which included resolving dependencies, refactors, re-configuration utilities, and gradual release of updates to ensure a smooth transition.
Conducted performance analysis and tuning of both front-end and back-end systems. This included removing React rendering bottlenecks and improving PostgreSQL performance on structural and query levels.
Developed and delivered front-end and back-end features that significantly improved the overall user experience of our product.
Troubleshot DocuSign integration issues and identified and resolved several previously undiscovered issues.
Addressed irregular issues during E2E testing, ensuring the product remained stable and reliable.
Created several QOL utilities for developers, including a cross-application JavaScript library linker and a database snapshot too, which helped streamline the development process and provide faster feedback.
Conducted in-depth code reviews of multi-level features and provided constructive feedback to team members, ensuring high code quality.
Provided help and guidance to colleagues in relevant areas of expertise.

Technologies: Ruby on Rails (RoR), JavaScript, Node.js, React, PostgreSQL, Makefile, Docker, Docker Compose, Cypress, SQL Performance, Ruby Performance, Code Review, Toolkits, API Integration, Test-driven Development (TDD), Jest, RSpec, Redux, SQL, Shell, Front-end, Amazon Web Services (AWS), Regex, Ruby, Distributed Systems, OAuth 2, Object-oriented Programming (OOP), REST, Design Patterns, Functional Programming, ECMAScript (ES6), Storybook, Redis, Playwright, Document Parsing, TypeScript, Webpack

Senior Front-end Engineer

2021 - 2022

Freelance

Architected and oversaw a small team on implementing a UI for an internal project prototype.
Researched and advocated libraries used for the UI project.
Planned and implemented the project deployment method from scratch.
Implemented API integration on the front-end project.
Trained and coached fellow team members in tooling and front-end design.

Technologies: JavaScript, TypeScript, Tailwind CSS, Redux, Alpine.js, Node.js, React, Front-end, Shell, Architecture, REST APIs, API Integration, Jest, Code Review, Regex, Distributed Systems, Object-oriented Programming (OOP), REST, Design Patterns, Functional Programming, ECMAScript (ES6)

Senior Full-stack Engineer

2021 - 2021

SameSystem

Implemented visual and logical components for front-end applications based on designs provided in React.
Designed and implemented a communication API layer on the front and back end.
Extended the existing back-end system to incorporate the newly developed module.
Implemented an extensible integration mechanism on the back end. Offered general consulting on system design and planning.
Refactored one of the running integrations as an exemplary implementation under the new module.

Technologies: React, Redux, Ruby on Rails (RoR), GraphQL, Apollo, Node.js, Full-stack, Front-end, Shell, Architecture, Management, REST APIs, Integration, SQL, Jest, Test-driven Development (TDD), Code Review, Ruby Performance, Regex, Ruby, OAuth 2, Python, Object-oriented Programming (OOP), REST, Design Patterns, ECMAScript (ES6), Storybook, Redis, Tailwind CSS

Senior Full-stack Lead Developer

2019 - 2021

Undisclosed Fortune 500 Toptal Client

Developed multiple client-facing, interactive features using React and Redux, including Three.js for 3D models.
Led effort to upgrade software stack by refactoring existing codebase while removing dated system components.
Designed and partially implemented a new contract for internal API communication.
Worked on improving development process by modernizing documentation solution, review and deployment process as well as optimizing team's sprint schedule.
Coached fellow team members on React development, intrinsic integration details as well as best practices.
Advocated for modernizing the stack shifting development from classical page-by-page development toward React stack.
Worked with business on the planning and providing estimations for various business related-features and other development efforts.
Made performance reporting and fixed bottlenecks using profiling, dry code analysis, and SQL query optimization.

Technologies: JavaScript, React, Ruby on Rails (RoR), PostgreSQL, Redux, Webpack, Storybook, Redis, Docker, RSpec, AVA.js, Playwright, Lodash, Three.js, SQL, Node.js, Full-stack, Amazon Web Services (AWS), Front-end, Shell, Architecture, REST APIs, API Integration, Toolkits, Code Review, Ruby Performance, Regex, Ruby, Distributed Systems, OAuth 2, Object-oriented Programming (OOP), REST, Design Patterns, ECMAScript (ES6)

Software Engineer and Acting CTO

2018 - 2018

Undisclosed Toptal Client

Worked with the CEO and the CMO on creating the MVP for the first round of funding.
Created the full-stack MVP with Elixir. GraphQL backed the back end and Bootstrap 4 connected the front end.
Owned the design development process along with implementation.
Decided on the tooling used for various design and implementation elements.
Interviewed and provided guidelines for the interview process of new hires.

Technologies: Object-oriented Programming (OOP), Design Patterns, Functional Programming, Docker Compose, React Apollo, Phoenix, Redux, Regex, Storybook, Webpack, ECMAScript (ES6), React, GraphQL, Elixir, JavaScript, TypeScript, Node.js, Full-stack, Amazon Web Services (AWS), Front-end, Shell, Architecture, Management, REST APIs, API Integration, Integration, SQL, OAuth 2

Software Engineer Consultant

2018 - 2018

Undisclosed Toptal Client

Worked on the prototype of the syntax analyzing tool across different languages using Ruby.
Provided the common layer for various syntax analyzers and linters with various levels of optional autocorrection.
Connected the prototype result to GitHub APIs, allowing instant result and correction options through GitHub's web UI.

Technologies: Object-oriented Programming (OOP), REST, Design Patterns, Docker Compose, Distributed Systems, Regex, Abstract Syntax Trees (AST), Docker, JavaScript 6, JavaScript, Node.js, Shell

Software Engineer Consultant

2013 - 2017

DragonBox

Designed and implemented user account services to use with various user-related services.
Conducted game progress and saved data analysis using R.
Designed and maintained the workflow for game deployment.
Developed and maintained the Q&A infrastructure of the game dev and web-related features.
Supported marketing with the development of websites, setting up email campaigns, and data slicing.
Built various game-related modules used by Unity-backed games.
Developed support tooling to be used by the game devs in the Unity environment.
Built analytics data consumption and transformation endpoint using Elixir/Phoenix.
Managed the tooling team during the development of the Unity package manager and the marketing team during CTO's leave.

Technologies: Object-oriented Programming (OOP), REST, Design Patterns, Abstract Syntax Trees (AST), Webpack, jQuery, Linux, Distributed Systems, Regex, PostgreSQL, D3.js, Phoenix, Elixir, Ruby on Rails (RoR), Ruby, Full-stack, Redis, Front-end, Shell, Management, REST APIs, API Integration, Integration, SQL, Test-driven Development (TDD), Toolkits, OAuth 2, RSpec

Project and Technical Manager

2010 - 2012

Voxcommerce Group Sp. z o.o.

Designed software for the development teams to develop through the implementation of stubs and prototypes.
Solved implementation roadblocks by providing guidance, coaching, and solutions to technical challenges.
Conducted business client analyses for new and existing clients.
Managed projects from the project acquisition until the successful delivery.
Planned and implemented software development processes.

Technologies: Object-oriented Programming (OOP), REST, Design Patterns, jQuery, Linux, Distributed Systems, Ruby, Regex, PostgreSQL, MySQL, Django, Python, Full-stack, Management, REST APIs, API Integration, Integration, SQL, Shell, Code Review, Front-end, Ruby on Rails (RoR)

Software Engineer

2008 - 2010

Voxcommerce Group Sp. z o.o.

Developed software with PHP for the real-estate industry.
Built CRM systems using self-developed frameworks.
Implemented direct client-to-server software related to a website design.
Set up and maintained servers infrastructure, i.e., cluster of dedicated servers.

Technologies: Object-oriented Programming (OOP), REST, Design Patterns, Linux, Distributed Systems, Regex, jQuery, Django, MySQL, PostgreSQL, Python, Full-stack, REST APIs, Integration, SQL

Experience

Sample PDF Generator

https://github.com/exlee/generate_pdf

A sample PDF Generator provides developers with a tool that can easily generate visually distinct PDFs with concrete parameters for setup with both simple and complex QA testing scenarios with precise parameters, such as the number of pages or file size.

Interactive Product Showcase - Build Your Roof

https://www.owenscorning.com/en-us/roofing/build-your-roof

A multi-step interactive builder showcasing products meant to be used both as a general solution and as an embedded widget with a high degree of customization. My main challenges were ensuring choice compatibility, providing easy-to-use API to external vendors, providing a customization layer, and integrating a 3D model into the application.

tree-sitter-pikchr

https://github.com/exlee/tree-sitter-pikchr

Implementation of Pikchr diagramming language using tree-sitter library/toolkit. The implementation was straightforward and based on official language specifications, but it includes extra tokens and some precedence rules.

Elixir Library for Semantic Markdown

https://github.com/exlee/ex_semantic_markdown

A self-made and published library for parsing markdown in Elixir language.

The library's purpose is to be able to parse popular markdown format while retaining some embedded semantic information as well as extending the original parsing library with some minor features like localization.

The project uses Elixir-provided capabilities to traverse parsed AST of markdown input while making some adjustments.

Seyph | Game

A fully in-house developed Unity game that was made as a software project.

The project's goal was to provide a start-to-end implementation and deployment of a sample game as a proof of concept for one of the partners.

The project included full architecture setup, project planning and documentation, implementation with a managed team, and deployment on the App Store.

Implementation of a Local Adapter for a Self-designed Dragon NaturallySpeaking Interface

This code isn't runnable per se, as it's part of a bigger project. This is an implementation of a local adapter for a Dragon NaturallySpeaking interface, which I also designed.

Broadly speaking, it is for communication between isolated apps and is prepared for a distributed deployment. The initial implementation focused on a local-only implementation, i.e., a project compiled from sub-projects into smaller projects by an integrator.

SBQL Implementation in Ruby

https://github.com/exlee/sbql4ruby

This is an implementation of SBQL in the Ruby language and was a part of my master's thesis for the Polish-Japanese Institute of Information Technology. While this selected project is non-commercial, it was the only one that can be shown in which I implemented a query language.

A Sample of Query Language Implementation

https://gist.github.com/exlee/4cab3b6962fbeb69d98d32b2b345cff0

A partial search query language implementation project for an in-house search engine. The project goal was to provide support operators with the ability to search for complex data structures while being proficient and easy to use.

Skills

Languages

ECMAScript (ES6), Regex, JavaScript, Ruby, Python, SQL, Elixir, GraphQL, TypeScript, JavaScript 6, Rust

Frameworks

Ruby on Rails (RoR), Redux, OAuth 2, Phoenix, Jest, Django, AVA.js, Tailwind CSS, Cypress

Libraries/APIs

React, Node.js, Lodash, REST APIs, Playwright, Three.js, D3.js, jQuery

Tools

Emacs, Docker Compose, Webpack, Shell, Makefile, RSpec, React Apollo

Paradigms

DRY, Object-oriented Programming (OOP), REST, Design Patterns, Functional Programming, Metaprogramming, Management, Test-driven Development (TDD)

Storage

PostgreSQL, SQL Performance, MySQL, Redis

Other

OOP Designs, Full-stack, Front-end, Distributed Systems, Document Parsing, Architecture, API Integration, Ruby Performance, Code Review, Integration, Storybook, Abstract Syntax Trees (AST), Apollo, Alpine.js, Toolkits

Platforms

Docker, MacOS, Linux, Amazon Web Services (AWS)

Education

2013 - 2013

Certification in Business Training

TenStep Poland Trainers School - Warsaw, Poland

2009 - 2011

Master's Degree in Software and Database Engineering

Polish-Japanese Institute of Information Technology - Warsaw, Poland

2007 - 2009

Bachelor's Degree in Management in IT

Warsaw Management University - Warsaw, Poland

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