Calvin is available for hire

Calvin DeBoer

Verified Expert in Engineering

Full-stack Developer

Location

Charlotte, NC, United States

Toptal Member Since

January 31, 2020

Calvin is a talented full-stack engineer with more than a decade of experience building web applications with open-source tools. His strong technical skills and business experience give him the ability to communicate to and create alignment between developers, product owners, stakeholders, and executives.

Data Modeling Back-end Software Development Software Integration CTO Microsoft Excel Python Databases ETL Django Unit Testing REST APIs Celery Pandas Julia Dev Team Leads DRF Django REST Framework Falcon

Portfolio

Toptal Clients

Python, TypeScript, Azure, Cloud, Django, FastAPI, React Native, APIs...

Horizon Investments

Julia, ClojureScript, Python, APIs, REST APIs, Back-end, API Integration...

Experience

Python - 15 years Data Modeling - 15 years Django - 13 years PostgreSQL - 12 years Team Leadership - 10 years Architecture - 8 years Project Leadership - 8 years Clojure - 4 years

Availability

Part-time

Preferred Environment

Slack, GitLab, Visual Studio Code (VS Code), Bash, Linux, MacOS

The most amazing...

...thing I've coded is an algorithm for fuzzy matching poorly constructed financial information to a highly structured schema.

Work Experience

Freelance Senior Software Engineer

2019 - PRESENT

Toptal Clients

Built a Python-based application that scrapes legal websites to gather court case updates and notifies followers of changes in dockets and other items. This application also gathers court filings for followers.
Enhanced a tax calculation and financial analysis SaaS project by adding user registration, payment, and calculation features.
Revitalized and transformed an old, legacy Node.js application, in the data-finance domain, into a well-tested Python-based application.
Performed security-focused application assessments and code reviews for various SaaS projects.

Technologies: Python, TypeScript, Azure, Cloud, Django, FastAPI, React Native, APIs, REST APIs, Back-end, Microsoft Excel, PostgreSQL, NumPy, Ansible, Sass, JavaScript, SQL, Project Management, Software Development, Software, Stripe API, Artificial Intelligence (AI), HTML, CSS, Application Architecture, Advisory, Docker, React, CI/CD Pipelines, Celery, Crypto, Pytest, Unit Testing, Testing, Google Cloud Platform (GCP), Google Cloud, User Experience (UX), Development, Pandas, Flask, Data Visualization, Data Engineering, Databases, ETL, Plotly, Dash, Integration

Chief Technology Officer

2006 - PRESENT

Horizon Investments

Created and contributed to several open-source projects, primarily in the financial services domain.
Developed several full-stack web systems using a variety of tools and technologies. The nature of these systems is confidential.
Adapted software processes and communication protocols to changing requirements and growing teams.
Built a productive team environment for developing durable and maintainable code.

Technologies: Julia, ClojureScript, Python, APIs, REST APIs, Back-end, API Integration, Microsoft Excel, Software Development Management, Sockets, Telnet Protocol, Architecture, Project Leadership, Team Leadership, Data Modeling, Clojure, PostgreSQL, NumPy, Ansible, Sass, Reagent, Ruby, SQL, MATLAB, SciPy, Re-frame, CTO, Project Management, Software Development, Software, Application Architecture, Advisory, Technical Analysis, Docker, React, CI/CD Pipelines, Tailwind CSS, Celery, Pytest, Unit Testing, Testing, Google Cloud Platform (GCP), Google Cloud, User Experience (UX), Development, Pandas, Data Engineering, Databases, ETL, Plotly, Dash, Integration

Experience

Iteround | Open Source Python Package

https://github.com/cgdeboer/iteround

Iteround is an organic, standard, and sum-safe rounding library for Python. It solves a typical problem where elements are in an array-like structure that needs to be rounded while maintaining the rounded some of the original array. This is typical in representing percentages.

Custom B2B eCommerce Application

A Python and Django-based eCommerce catalog application with integrations to legacy inventory management systems, including SAP. This application also supported multiple languages and served a primarily B2B audience.

AI Web App | Security and Performance Improvements

A Python-based AI application. Initially, I was tasked with conducting a security review using OWASP Top 10 guidelines. Furthermore, I led efforts aimed at upgrading the authentication systems. Additionally, I guided a team of more junior engineers, assisting them through important refactors to enhance the system's performance.

Web Scraping Notification Tool | Lead Engineer

Acted as the sole developer building a Python-based web scraping application that investigates changes in the PACER court reporting system related to selected dockets and summarizes reports for the interested parties.

Skills

Languages

Python, HTML, Julia, Sass, Clojure, CSS, Bash, TypeScript, JavaScript, Ruby, Falcon, SQL, Python 3

Frameworks

Django REST Framework, Django, ClojureScript, Re-frame, Flask, React Native, Tailwind CSS

Libraries/APIs

REST APIs, Pandas, NumPy, SciPy, React, Sockets, Stripe API, Django ORM

Tools

Microsoft Excel, Celery, Pytest, Reagent, Ansible, Plotly, GitLab, Slack, MATLAB, Git

Paradigms

Application Architecture, Unit Testing, Testing, ETL, Functional Programming, REST

Storage

Google Cloud, Databases, PostgreSQL, MySQL

Other

Data Modeling, Project Leadership, Team Leadership, Architecture, APIs, Back-end, API Integration, CSV, Software Development Management, CTO, Software Development, Software, Advisory, CI/CD Pipelines, Development, Integration, Project Estimation, FastAPI, Fintech, Artificial Intelligence (AI), Technical Analysis, Crypto, User Experience (UX), Data Visualization, Data Engineering, Dash, Cloud, Financial Services, Writing & Editing, Product Ownership, Security Analysis, Analytics, Sanic Web Server, SaaS, IT, Faceted Search, eCommerce, Search Engines, Search, Algorithms, Full-stack, Web Scraping, Telnet Protocol

Platforms

Amazon Web Services (AWS), Google App Engine, Docker, Google Cloud Platform (GCP), Mailgun, Azure, Linux, MacOS, Visual Studio Code (VS Code)

Industry Expertise

Project Management

Education

2004 - 2007

Bachelor's Degree in Finance and Economics

University of North Carolina at Charlotte - Charlotte, NC, USA

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