Frank is currently unavailable
Frank Hall
Verified Expert in Engineering
Full-stack Developer
Lexington, MO, United States
Toptal member since May 28, 2024
Bio
Frank is an exceptionally skilled computer scientist with over 20 years of hands-on experience. He excels at developing high-performance solutions to intricate issues and rapidly adapts to new technologies as needed for tailored business solutions. With a profound and extensive understanding of the SaaS domain, Frank brings a wealth of knowledge to every project.
Portfolio
Wahoo Fitness
Ruby on Rails (RoR), TypeScript, C, AWS Lambda, Node.js, Docker, Assembler x86...
Instacart
Ruby, Ruby on Rails (RoR), JavaScript, TypeScript, Docker, RSpec...
Teladoc
Ruby, Ruby on Rails (RoR), Docker, Docker Compose, Apache Kafka...
Experience
- C - 20 years
- Ruby - 20 years
- REST - 20 years
- JavaScript - 20 years
- APIs - 20 years
- Linux - 20 years
- Ruby on Rails (RoR) - 19 years
- RSpec - 17 years
Preferred Environment
RubyMine, Slack, Slackware
The most amazing...
...solution I've developed is a multi-process/threaded event-driven service that dynamically combines data from multiple systems used in over 80% of all web calls.
Work Experience
Senior Full-stack Developer
2023 - 2024
Wahoo Fitness
- Maintained and improved the Rails cloud infrastructure, handling the back end for fitness hardware and customer services.
- Built and deployed AWS Lambda service using JavaScript. Created an automated deployment process to allow other teams to make updates.
- Debugged issues with internal Flexible and Interoperable Data Transfer (FIT) file processor utilizing core dumps, x86 assembly, and C.
- Automated the deployment of additional Rails and Node.js services using GitLab CI/CD, Kubernetes, and AWS.
- Rebuilt existing Docker images to improve security and performance.
- Upgraded cloud infrastructure from Ruby 2.6/Rails 6.0 to Ruby 3.2.3/Rails 7.1.3.2.
Technologies: Ruby on Rails (RoR), TypeScript, C, AWS Lambda, Node.js, Docker, Assembler x86, Kubernetes, Amazon Web Services (AWS), Docker Compose, Ruby, Minitest, Continuous Integration (CI), APIs, REST APIs, JavaScript, PostgreSQL, IT Security, Code Review, API Integration, Ruby on Rails API, CSS, HTML, SQL
Senior Full-stack Developer
2023 - 2023
Instacart
- Worked with the professional services team on their external interfaces that communicate with other companies to provide seamless integration with their existing infrastructure and Instacart.
- Helped diagnose issues with their current development toolchain.
- Assisted multiple other teams in integrating with internal and external services.
Technologies: Ruby, Ruby on Rails (RoR), JavaScript, TypeScript, Docker, RSpec, Continuous Integration (CI), APIs, REST, REST APIs, PostgreSQL, Code Review, API Integration, Ruby on Rails API, CSS, HTML, SQL
Staff Engineer
2021 - 2023
Teladoc
- Designed a high throughput, distributed service linking multiple independent systems across the sub-companies, enabling a complete overhaul of the entire architecture.
- Simplified integration of Kafka, Google Protobuf, GraphQL, Scala services, Redis, and Rails servers.
- Created standardized client interfaces for existing remote servers, making them appear as if they were RESTful.
- Extracted tightly embedded code into standalone gems and engines.
- Enhanced RSpec test quality by increasing coverage while lowering testing time to less than 1% of the initial duration.
Technologies: Ruby, Ruby on Rails (RoR), Docker, Docker Compose, Apache Kafka, Google Protocol Buffer, GraphQL, Scala, JavaScript, TypeScript, Redis, REST, RSpec, REST APIs, PostgreSQL, IT Security, Code Review, API Integration, Ruby on Rails API, CSS, HTML, SQL
Senior Full-stack Developer
2019 - 2021
Cherokee Nation Business
- Worked with the National Institute of Food and Agriculture to maintain and improve their seven main existing Rails applications, which had not had an active Rails developer for multiple years.
- Identified and fixed multiple potential security breaches.
- Improved data integrity and implemented automated recovery features for identified corrupted data.
- Mapped the core functionality of thousands of unknown and undocumented code lines to identify system inter-dependencies.
Technologies: Ruby, JRuby, Ruby on Rails (RoR), Docker, Docker Compose, Security, Continuous Integration (CI), REST APIs, JavaScript, PostgreSQL, IT Security, Code Review, API Integration, Ruby on Rails API, CSS, HTML, SQL
Individual Consultant
2017 - 2019
Cerner
- Optimized data processing for vast data sets, significantly reducing the time required to process thousands of related data entries. In some cases, these reductions dropped a 15-minute processing time to under 8 seconds.
- Worked with the collaboration team to build the first external application to interface with the core Cerner product Millennium. This application consisted of a back-end Rails API layer and a front-end React/Redux layer.
- Created a rules processing engine to facilitate the front-end and back-end data validation.
- Wrote libraries and consumable gems to interface with other web APIs. Thus reducing the learning curve of using these APIs and shielding end users from changes in those remote APIs or endpoint locations.
Technologies: Ruby, Ruby on Rails (RoR), JavaScript, React, Redux, REST, RSpec, Continuous Integration (CI), APIs, REST APIs, PostgreSQL, IT Security, Code Review, API Integration, Ruby on Rails API, CSS, HTML, SQL, MongoDB
Individual Consultant
2014 - 2016
Treverity
- Implemented a reflection-aware Scala and JavaScript code platform.
- Created multiple UI interfaces to allow companies to comprehend the large amount of data being monitored.
- Extended the core Scala Play Framework, which was the core framework of the SaaS.
Technologies: Scala, JavaScript, Play Framework, Amazon Web Services (AWS), REST APIs, PostgreSQL, IT Security, Code Review, API Integration, Ruby on Rails API, CSS, HTML, SQL
Experience
Data Integration Service
A Rails application designed to run multiple instances, each multi-threaded, to integrate customer data from various internal servers that were never designed to interoperate. The entire process was even driven and scalable, and deadlocks were avoided while maintaining data integrity without the benefit of a database. The API to this service would be used in over 80% of web traffic. I designed and implemented the solution.
Performance was a huge concern. Ultimately, the limiting factors were the other systems being contacted as they reached their limits while my code was still under 2% resource utilization. Despite this, the client calls were never blocked, thus no additional delays in web processing from the user's perspective.
Performance was a huge concern. Ultimately, the limiting factors were the other systems being contacted as they reached their limits while my code was still under 2% resource utilization. Despite this, the client calls were never blocked, thus no additional delays in web processing from the user's perspective.
Prime Miller Rabin
https://rubygems.org/gems/prime_miller_rabinA large prime factorization for Ruby using the Prime Miller Rabin method for primality testing. It exceeds the performance of Ruby's built-in prime generators and testers. Ruby's internal C methods can take over two minutes, factoring numbers near 10^20. This project factors numbers reaching 10^100 while remaining sub-second.
Education
1997 - 1999
Graduate Degree in Computer Science
University of Missouri - Columbia, MO, USA
1991 - 1995
Bachelor's Degree in Computer Science
Northwest Missouri State University - Maryville, MO, USA
Skills
Libraries/APIs
REST APIs, Ruby on Rails API, Node.js, React
Tools
RSpec, Docker Compose, RubyMine, Slack
Languages
Ruby, HTML, TypeScript, C, Assembler x86, JavaScript, GraphQL, JRuby, Python, C++, CSS, SQL, Scala, Ada
Frameworks
Ruby on Rails (RoR), Google Protocol Buffer, Redux, Play Framework, ActionCable
Paradigms
REST, Continuous Integration (CI)
Platforms
Slackware, Linux, AWS Lambda, Docker, Kubernetes, Amazon Web Services (AWS), Apache Kafka
Storage
Redis, Relational Databases, PostgreSQL, MongoDB
Other
Security, APIs, Software as a Service (SaaS), Code Review, API Integration, Minitest, IT Security, Computer Science
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.
1
Share your needs
Discuss your requirements and refine your scope in a call with a Toptal domain expert.
2
Choose your talent
Get a short list of expertly matched talent within 24 hours to review, interview, and choose from.
3
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