Alexander Wilczewski, Developer in Denver, CO, United States
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Alexander Wilczewski

Verified Expert  in Engineering

Full-stack Developer

Denver, CO, United States
Toptal Member Since
August 19, 2021

Alex is a full-stack developer with an array of soft skills and notes of DevOps capabilities. He knows that regular communication is vital to ensure accurate direction and accountability. Having worked among startups, Alex can ramp up quickly to any project. After studying within an enterprise, he is capable of leadership, task breakdown, and drawing out project designs.


Node.js, Git, GitHub, Amazon Web Services (AWS), Amazon RDS, Amazon S3 (AWS S3)...
Freelance Client
Windows Subsystem for Linux (WSL), Node.js, Auth0, JSON Web Tokens (JWT)...
Freelance Client
JavaScript, CSS, HTML, WordPress, Vue, Advanced Custom Fields (ACF), PHP...




Preferred Environment

C#, .NET, JavaScript, MariaDB

The most amazing...

...project I've led was an aggregated logger for our many enterprise applications, allowing proactive insights and diagnostics.

Work Experience

Technical Lead

2021 - PRESENT
  • Reduced AWS costs by 80% by analyzing and reducing database and compute sizes to match needs and replacing resources with managed AWS services.
  • Advised on process and documentation decisions for nonprofit board management and organization.
  • Improved security for our third-party services (AWS, GitHub, Auth0), as well as within our cloud document management service (Google Drive).
  • Maintained and developed features for a React administrative web app, a Node.js/Express.js API middle tier, and our user-facing React Native Android/IOS mobile application.
  • Coordinated and led projects for volunteer staff. Projects included data collection and measurement using Google Sheets and Google Forms, collection of geolocation from IP addresses, and replacement of third-party services to protect user data.
  • Collaborated with external organizations to understand the data privacy needs of our users, creating timelines to complete projects to protect our users.
  • Converted Node.js API middle tier to TypeScript from Babel. The intention is to help developers refactor code.
  • Built tooling to easily deploy within the AWS ecosystem. Automated CLI instructions included interacting with S3, CloudFront, CodeBuild, and ECS.
Technologies: Node.js, Git, GitHub, Amazon Web Services (AWS), Amazon RDS, Amazon S3 (AWS S3), Amazon Simple Email Service (SES), AWS IAM, AWS CLI, AWS Fargate, MariaDB, Metabase, React, React Native, NPM, Papertrail, SendBird, Auth0, Mailchimp, JavaScript, Slack, Google, Jira, JSON Web Tokens (JWT), Express.js, SQL, TypeScript, Babel, Full-stack, Looker, Google BigQuery, Firebase, SendGrid, Google Sheets, Google Forms, Docker, Zapier, Notion, Firebase Cloud Messaging (FCM)

Full-stack Developer

2021 - 2022
Freelance Client
  • Upgraded all npm dependencies and updated source code during breaking changes.
  • Improved onboarding documentation to match correct versions of dependencies and recorded steps to set up Windows Subsystem for Linux (WSL) on Windows.
  • Communicated work asynchronously with the team through GitHub issues.
  • Developed retained sign-in feature while the user was interacting with the web app.
Technologies: Windows Subsystem for Linux (WSL), Node.js, Auth0, JSON Web Tokens (JWT), GitHub, JavaScript, Vue, MongoDB, NPM

WordPress Developer

2021 - 2021
Freelance Client
  • Coordinated with project owner and designer to assemble project scope and timeline using Asana.
  • Created pixel-perfect, reactive web app from design specification using Bootstrap and Vue.
  • Developed administrative process within WordPress admin using Advanced Custom Fields and custom post types.
  • Improved site performance to be 70+ for PageSpeed Insights.
Technologies: JavaScript, CSS, HTML, WordPress, Vue, Advanced Custom Fields (ACF), PHP, Bootstrap, Asana

Senior Software Engineer

2018 - 2021
City and County of Denver
  • Researched new technology and how it could be integrated, including Azure TTS, a Cisco phone system call tree, Twilio, Mailchimp, state systems, and Microsoft Power Automate API.
  • Built technical designs for the development team, including a client portal, a deployment tool, an aggregate log, and a mass messenger.
  • Created an architectural vision for our technology stack that covered tokens, queues, Pub/Sub, system agnostic locks, API wrappers, and object-oriented patterns.
  • Mentored two interns for a CronJob migration from SQL Server procedures to C#.
  • Oversaw the project to convert Oracle to SQL server, coordinating between our team and the project manager.
  • Developed an internal custom application written in Visual Basic and C# used daily by 600 employees.
  • Discussed product designs with project managers and broke down tasks for the internal development team for windows applications, web apps, internal tools, and long-running services.
  • Assisted in developing a C# web app used by internal and external teams. The front end combined ASP.NET, vanilla JavaScript, and Vue 2.
Technologies: Git, Windows, Visual Studio, Visual Studio Code (VS Code), C#, .NET, ASP.NET, IIS, SQL Server 2017, Oracle SQL, JavaScript, Vue, Windows PowerShell, Azure, Architecture, Design, Pub/Sub, APIs, C#.NET, ASP.NET MVC, ASP.NET Core, Agile Project Management, Project Design & Management, Web Project Management, Vanilla JS, Front-end, Microsoft Excel, SQL, Full-stack, SignalR

Senior Web Developer

2014 - 2018
  • Created several web-based single-page applications (SPA) written with PHP and Angular with communication done through HTTP APIs in JSON.
  • Acted as a product owner of five applications, all of which were 90% unit tested.
  • Designed and implemented insights architecture with a combination of the Pipe and Filters pattern (PHP), Blackboard, and OOP.
  • Built PulseLink that had an IE8 minimum requirement: it was used by the front desk and needed to be quick to load and fast to use.
  • Rebuilt RoomPulse into an AngularJS single-page application: it had an IE9 minimum requirement and served as a back-office utility.
  • Designed multiple reusable Angular components, including typeahead, dropdown, list multi-selection, and modal.
  • Developed an open-Source script to watch GitHub repositories for version changes.
  • Created a UI by bootstrapping JavaScript to accelerate ATF loading.
Technologies: Kubuntu Linux, VirtualBox, Git, Apache, NetBeans, Visual Studio Code (VS Code), NPM, Bower, Grunt, TypeScript, JavaScript, Angular, HTML, CSS, PHP, MySQL, Object-oriented Programming (OOP), Grunt Command Line Interface (CLI), ParcelJS, Web Project Management, Vanilla JS, Front-end, APIs, Ubuntu, SQL, Full-stack

Full-stack Web Developer

2011 - 2014
  • Redeveloped our guest-facing upsell solution by utilizing Node.js and AngularJS which decreased page load size by 50%.
  • Educated coworkers on technologies including Node.js, AngularJS, Canvas, and Google App scripts through presentations showing the pros and cons and usage.
  • Presented, with the VP of marketing, the release of our APIs for the 2013 Tnooz THack.
  • Created an Android application that utilized internal API calls; my focus was on usability and performance.
  • Enhanced our internalization system by supporting lazy-loading keywords which improved manager efficiency.
  • Worked closely with the UX designer to implement a mobile design.
  • Wrote an administrative service-based web apps using CakePHP in a collaborative Scrum environment.
Technologies: Jira, MacOS, Git, Subversion (SVN), Apache, NetBeans, Eclipse, Android Studio, Genymotion, PHP, CakePHP, Node.js, JavaScript, jQuery, Angular, HTML, CSS, MySQL, Agile Project Management, Web Project Management, Vanilla JS, Front-end, Ubuntu, SQL, Full-stack

Web Developer

2007 - 2011
HPN WorldWide
  • Reformed an aggregate report system which reduced the script run time from ten minutes to two minutes.
  • Optimized a web printable 16-page HPA report to have backward compatibility for IE6.
  • Developed a utility to import collections of thousands of unique screenings—saving several hours each week.
  • Created several tracking systems to implement client-specific requests.
Technologies: PHP, Symphony, FileMaker, HTML, CSS, MacOS, Git, Apache, Eclipse, Doctrine, JavaScript, MySQL, Front-end, Vanilla JS, SQL, Full-stack

CAD Handwheel Generator

It is a naval challenge project: it is too costly for a naval craft to carry extra handwheels, and each naval craft may have many different-sized handwheels.

As an alternative solution, vehicles will have a computer and a 3D printer. An operator can enter the handwheel dimensions and output a procedurally generated CAD file for 3D print to replace any broken handwheels.

Conference Attendance Web App

A Node.js-based CMS that allows users to register for interesting talks and pay through PayPal. Added administrative functionality to organize attendees, batch email attendee assignments, and export attendance as CSV. The web application is re-run by the client yearly.

EE Lessons

Empowering Education (EE) is a nonprofit that provides mindfulness content for educators to bring to the classroom. Users will log in to the online service to access lessons, download content, and see usage examples.

The chosen solution to the project was to build a custom post type in WordPress that integrates with pre-existing functionality. This allows the EE editors to manage the lessons entirely by themselves. Including managing content, the template, additional data, and user access.

This project allowed me to work with WordPress and extend its feature base. I was able to create a custom post type. I integrated with advanced custom fields to build the form. EE already chose Divi as their templating engine, and I was able to create a custom template. Lastly, they use Memberful for user role access. By utilizing each of the integrations already present, EE can manage this feature on their own.

WordPress Page Speed Optimization
Candle Inc. was looking to improve its Core Web Vitals to support better SEO. With only access to WordPress, I configured several plugins to speed up the site. As a result, the company's Core Web Vitals went from 25 to 65.

Power Automate Flow for Non-technical Users

The project served as a business process intermediary and proof-of-concept. We used Microsoft Forms as a front end, Microsoft Excel as a database, Power Automate as a business layer, and Power BI as an administrative tool. Internal users could look clients up in the Power BI system and enter a unique ID in the Microsoft Forms to allow updates. Several Power Automate flows were built from Microsoft Form triggers. One Microsoft Form was a 100+ questionnaire. The Power Automate design chosen was the ease of maintenance for a non-technical user. For example, conditional branches were never more than a single layer deep—the management from the block editor would be complex.

Automation of Accounting Needs for a Freelancer

The client required an API connection between Harvest time tracking and Wave. The requirement was to copy over invoicing data. I researched and found MakeHQ that would support their needs within their budget. With MakeHQ, I created an automated no-code API web flow that they could manage if necessary.
2007 - 2011

Bachelor's Degree in Computer Science

Elmhurst College - Elmhurst, IL, United States

AUGUST 2021 - AUGUST 2025

AWS Certified Developer - Associate

Amazon Web Services


Vue, Node.js, jQuery, Doctrine, PayPal API, React, SendBird, SignalR


Git, Apache, Visual Studio, Grunt Command Line Interface (CLI), Asana, FreeCAD, FileMaker, Jira, Subversion (SVN), Android Studio, Genymotion, VirtualBox, NPM, Bower, Grunt, Advanced Custom Fields (ACF), Microsoft Power BI, Microsoft Excel, Webpack, Auth0, GitHub, Amazon Simple Email Service (SES), AWS IAM, AWS CLI, AWS Fargate, Papertrail, Mailchimp, Slack, Amazon CloudFront CDN, Babel, Looker, SendGrid, Google Sheets, Google Forms, Zapier, Make, Notion, Firebase Cloud Messaging (FCM)


.NET, CakePHP, Angular, ASP.NET, Windows PowerShell, Vanilla JS, ASP.NET MVC, ASP.NET Core, Windows Presentation Foundation (WPF), .NET Core, Divi, Bootstrap, JSON Web Tokens (JWT), React Native, Express.js


C#, JavaScript, PHP, SQL, C#.NET, Java, HTML, CSS, Flash ActionScript, C++, Assembly, Python, TypeScript, Sass


MySQL, SQL Server 2017, Oracle SQL, MongoDB, MariaDB, Amazon S3 (AWS S3), Amazon DynamoDB


Windows, Ubuntu, MacOS, NetBeans, Visual Studio Code (VS Code), Azure, Eclipse, Kubuntu Linux, KeystoneJS, WordPress, Microsoft Power Automate, Amazon Web Services (AWS), AWS Elastic Beanstalk, AWS Cloud Computing Services, Firebase, Docker


Agile Project Management, Object-oriented Programming (OOP), Automation


Full-stack, Operating Systems, Data Structures, IIS, Architecture, Design, Front-end, APIs, Web Project Management, Algorithms, Networking, Symphony, Pub/Sub, ParcelJS, Project Design & Management, Windows Subsystem for Linux (WSL), Amazon RDS, Metabase, Google, Wave, Harvest, Google BigQuery

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