Paul is available for hire
Hire PaulPaul Keen
Verified Expert in Engineering
CTO Developer
Location
Berlin, Germany
Toptal Member Since
November 12, 2019
Paul is a personal consultant with 15+ years of experience in full-stack software development. He architects solutions that are easy to support and scale, implementing best coding and management practices by continuously improving technical approaches. He focuses on test-driven development and is a Kanban practitioner.
Portfolio
OrchestrateCS
Ruby on Rails (RoR), Stimulus, Continuous Delivery (CD), Kanban...
JetThoughts
Ruby on Rails (RoR), CTO, Agile Coaching, Continuous Deployment...
Gilad Novik (via Toptal)
React Native, JavaScript, React, Continuous Integration (CI), Kanban...
Experience
Availability
Full-time
Preferred Environment
Kanban, GitHub, Test-driven Development (TDD), JavaScript, Ruby on Rails (RoR), Team Leadership, Leadership, Ruby, Continuous Delivery (CD), Agile DevOps, Go
The most amazing...
...experience was as a top 100 Ruby on Rails contributor where I helped numerous open-source projects like Ruby on Rails (Top100), Bundler, and more.
Work Experience
Fractional CTO
2021 - PRESENT
OrchestrateCS
- Launched the first version of the application, within the first 4 months of operations, so the sales and marketing teams were able to use it right away.
- Led the distribution efforts across worldwide teams, for the task development process.
- Automated the delivery process and set up quick feedback for developers.
Technologies: Ruby on Rails (RoR), Stimulus, Continuous Delivery (CD), Kanban, Product Discovery, Stakeholder Management, Lean, DevOps, Team Leadership, Docker, CTO, Team Mentoring, GitOps
CTO, Founder
2008 - PRESENT
JetThoughts
- Build 5+ R&D for product companies in Ukraine, with 20+ developers per each.
- Provided technical consultations to the clients, building a successful strategy, effectively structuring teams and processes.
- Delivered scalable web and mobile applications using Ruby on Rails and modern JavaScript frameworks (Node.js, React, Vue.js, AngularJS).
- Developed a framework for simple collaboration to reduce waste in product development. Clients distinguish communication approaches as a critical factor for mutually beneficial cooperation.
- Designed code practices to help the team deliver a stable product. It improves team effectiveness and guarantees the quality and scalability of provided solutions.
- Built strong partnerships with clients like Moscow Institute of Physics and Technology (Top 3 University of Russian Federation), DefMethod, Knight Foundation, and others.
- Set up a process to onboard, mentor, and train developers to help them to work as influential team members on the client's projects.
Technologies: Ruby on Rails (RoR), CTO, Agile Coaching, Continuous Deployment, Technical Leadership, Team Mentoring, Test-driven Development (TDD), JavaScript, Leadership, Team Leadership, Continuous Integration (CI), Extreme Programming, Continuous Delivery (CD), Management, Cypress, Infrastructure, Director, Kanban, CircleCI, Capybara, Remote Work, Lean Development, AngularJS, RSpec, GitHub, Heroku, JavaScript Testing, MySQL, PostgreSQL, Executive Coaching, Angular, Agile Leadership, Agile Delivery, Nuxt.js, SAML-auth, Legacy Code, Platform as a Service (PaaS), Agile DevOps, Tailwind CSS, Crystal, RETS, Scrum Master, Material Design, Account Management, Customer Success, Web Application Architecture, REST, Design Patterns, Docker Compose, Remote Team Leadership, SAML, Amazon Web Services (AWS), Amazon S3 (AWS S3), Web Architecture, Agile, jQuery, QA Automation, Ruby, TypeScript, Architecture, Docker, DevOps, GitOps, Product Discovery, Stimulus
React Native Developer
2019 - 2020
Gilad Novik (via Toptal)
- Upgraded old React Native application to use last React Native 0.61 and React Native Navigation from 1.x to 4.x.
- Researched the legacy code and refactored it to upgrade not-supported dependencies.
- Onboarded testing for the legacy code. Enabled it to allow to check integrations on different devices.
Technologies: React Native, JavaScript, React, Continuous Integration (CI), Kanban, Remote Work, GitHub, JavaScript Testing, Agile Delivery, Legacy Code, REST, Design Patterns, Web Architecture, Agile, QA Automation, Ruby, Continuous Deployment, TypeScript, DevOps, GitOps, Continuous Delivery (CD)
CTO, Technical Partner
2014 - 2018
Agent Inbox (Freelance)
- Contributed to the growth and recognition of Agent Inbox, the world's leading real estate messaging platform.
- Designed technical architecture, mentored team, and resolved problems of product users.
- Solved problems that restricted the team's ability to deliver the product, reworked the previous solution, simplified the codebase, optimized the development process using Lean principles.
- Delivered the first MVP within two months, which allowed founders to attract investors and customers and increase the investments to scale the development.
- Reduced risks of having new bugs implementing the development optimization: introduced code review, eliminated unnecessary routines, and integrated automatized tests, which significantly reduced the cost of new developers' onboarding process.
- Scaled the team to six developers in one year. Set up distributed onboarding process to make the team responsible for self-organization.
- Implemented the high standards for code solutions got companies willing to acquire the product.
Technologies: SAML, React, React Native, Ruby on Rails (RoR), CTO, Technical Leadership, Continuous Delivery (CD), Lean, Kanban, Test-driven Development (TDD), JavaScript, Leadership, Team Leadership, Continuous Integration (CI), Extreme Programming, Management, Infrastructure, CircleCI, Capybara, Remote Work, Lean Development, RSpec, GitHub, Heroku, JavaScript Testing, PostgreSQL, Executive Coaching, Team Mentoring, Agile Leadership, Angular, Agile Coaching, Agile Delivery, SAML-auth, Legacy Code, Platform as a Service (PaaS), Agile DevOps, Scrum Master, Web Application Architecture, RETS, REST, Director, Design Patterns, Docker Compose, Remote Team Leadership, Amazon Web Services (AWS), Amazon S3 (AWS S3), Web Architecture, Agile, jQuery, QA Automation, Ruby, Continuous Deployment, TypeScript, Architecture, Docker, DevOps, GitOps
VP Engineering, R&D Director
2014 - 2017
Faria Education Group (Freelance)
- Managed full-cyсle of product development and design architecture improvements for Open Apply. The technology stack is based on Ruby on Rails and React.
- Improved collaboration with related departments to organize effective product updates. Grew the R&D office in Ukraine.
- Built a long-term refactoring strategy to simplify the codebase. It increased team effectiveness by 20% in 3 months.
- Removed high-performance computing operations for application and tests, reducing the whole test suite time from 1 hour to 15 min.
- By integration, Lean principles and automatized tests prevented the accretion of new regression bugs. A list of known bugs was reduced from 500 to 10 within three months instead of growing each month, as it was before.
- Helped the team deliver a full redesign of the legacy functionality in 2 weeks instead of an estimated three months.
- Integrated code and management practices to scale the team of developers from five to 20 in six months without any velocity decrease.
- As a result, the team was willing to add more checks to prevent regressions, and the cost of adding a new feature was decreased by $33,000 per month.
Technologies: Amazon Web Services (AWS), PostgreSQL, React, Ruby on Rails (RoR), Technical Leadership, Agile Coaching, Lean, Continuous Delivery (CD), Director, Engineering, Test-driven Development (TDD), JavaScript, Team Leadership, Leadership, Continuous Integration (CI), Extreme Programming, Management, Infrastructure, Kanban, CircleCI, Capybara, Remote Work, Lean Development, RSpec, GitHub, Heroku, JavaScript Testing, Team Mentoring, Agile Leadership, Agile Delivery, SAML-auth, Legacy Code, Platform as a Service (PaaS), Agile DevOps, Scrum Master, Web Application Architecture, REST, Design Patterns, Docker Compose, Remote Team Leadership, SAML, Amazon S3 (AWS S3), Web Architecture, Agile, jQuery, QA Automation, Ruby, Continuous Deployment, Architecture, Docker, CTO, DevOps, GitOps
Senior Full-stack Engineer
2012 - 2014
BigBinary (Freelance)
- Developed code practices to have Ruby on Rails Testable Architecture.
- Created processes to run a remote development team.
- Set up R&D in Eastern Europe with remote onboarding and provided visibility to prevent wastes and problems.
Technologies: PostgreSQL, Ruby on Rails (RoR), Technical Leadership, Agile DevOps, Continuous Delivery (CD), Lean, Test-driven Development (TDD), JavaScript, React, Leadership, Team Leadership, Continuous Integration (CI), Extreme Programming, Infrastructure, Kanban, CircleCI, Capybara, Remote Work, Lean Development, RSpec, GitHub, Heroku, JavaScript Testing, Team Mentoring, Agile Delivery, Legacy Code, Platform as a Service (PaaS), Web Application Architecture, REST, Design Patterns, Amazon Web Services (AWS), Amazon S3 (AWS S3), Web Architecture, Agile, jQuery, QA Automation, Ruby, Continuous Deployment, Architecture, Docker, DevOps, GitOps
Experience
Agent Inbox
Agent Inbox envisioned taking real estate communication to the next level. They hired us to build the right platform, deliver a market-ready solution, and help the team grow.
Accomplishments:
• Set up a transparent process
• Built R&D team: scaled from 1 developer to 10 developers
• Got customer satisfaction and business recognition
• Led strategy and directed scaling, architecture, engineering, supervised product and data, science teams
• Developed technology platforms and mobile products using front-end frameworks, including Ruby on Rails/React/React Native with REST APIs
• Developed data pipelines for driving massive ETL architectures to support extraction, ingestion, formatting, and matching of data
• Automated CI/CD pipelines using the following technologies: Docker, Kubernetes, GitHub
• Delivered production systems with real-time monitoring, alerting, and logging to reduce the needs of having operational staff
• Provided direct support to founders for M&A discussions for product acquisitions
Accomplishments:
• Set up a transparent process
• Built R&D team: scaled from 1 developer to 10 developers
• Got customer satisfaction and business recognition
• Led strategy and directed scaling, architecture, engineering, supervised product and data, science teams
• Developed technology platforms and mobile products using front-end frameworks, including Ruby on Rails/React/React Native with REST APIs
• Developed data pipelines for driving massive ETL architectures to support extraction, ingestion, formatting, and matching of data
• Automated CI/CD pipelines using the following technologies: Docker, Kubernetes, GitHub
• Delivered production systems with real-time monitoring, alerting, and logging to reduce the needs of having operational staff
• Provided direct support to founders for M&A discussions for product acquisitions
Open Apply
http://openapply.comAs its client base grew, Faria Education Group (FEG) needed to ensure its OpenApply product could accommodate increasing demand. The problem? There were a lot of bugs within the code, and FEG didn't have any governing project management structure or unified documentation processes in place to address the growing issue.
Accomplishments:
• Set up a transparent process
• Applied practices to deliver changes with confidence
• Built R&D team: scaled from 2 to 20 developers and QA
• Increased sales and customer satisfaction
• Enhanced code readability for better product performance. We drastically enhanced the product's code readability to set the product up for current and future success. Our code quality rank on Code Climate was raised from level F to A. Plus, we significantly reduced bug risks by introducing code practices and efficient tests.
• Improved rendering for faster performance. We reduced the average request processing time from 3 seconds to 0.2 seconds, and the average page rendering time dropped from 600 ms to 200 ms.
Accomplishments:
• Set up a transparent process
• Applied practices to deliver changes with confidence
• Built R&D team: scaled from 2 to 20 developers and QA
• Increased sales and customer satisfaction
• Enhanced code readability for better product performance. We drastically enhanced the product's code readability to set the product up for current and future success. Our code quality rank on Code Climate was raised from level F to A. Plus, we significantly reduced bug risks by introducing code practices and efficient tests.
• Improved rendering for faster performance. We reduced the average request processing time from 3 seconds to 0.2 seconds, and the average page rendering time dropped from 600 ms to 200 ms.
Knight Foundation
http://knightfoundation.orgKnight Foundation is a national foundation with strong local roots. They invest in journalism, the arts, and the success of cities where brothers John S. and James L. Knight once published newspapers.
Accomplishments:
• Set up a transparent process
• Applied practices to deliver changes with confidence
• Production release decreased from 1 day to 0.5 hours
Accomplishments:
• Set up a transparent process
• Applied practices to deliver changes with confidence
• Production release decreased from 1 day to 0.5 hours
Mobile Coach
http://mobilecoach.comMobile Coach is a game-changing innovation for how enterprises influence employee engagement, learning, customer service, sales performance, and overall behavior change.
Accomplishments:
• Set up a transparent process
• Applied practices to deliver changes with confidence
• Built R&D team: scaled from 2 to 10 developers
• Increased sales and customer satisfaction
Accomplishments:
• Set up a transparent process
• Applied practices to deliver changes with confidence
• Built R&D team: scaled from 2 to 10 developers
• Increased sales and customer satisfaction
Campsyte
Campsyte was created with a vision to build better cities. The cities have become less affordable and more fragmented, and Campsyte seeks to give people a sense of ownership and belonging, and together build happier cities.
Accomplishments:
• Set up a transparent process
• Delivered beta in quickly
• Helped to get paying users in just a few months
Accomplishments:
• Set up a transparent process
• Delivered beta in quickly
• Helped to get paying users in just a few months
Skills
Languages
JavaScript, Ruby, TypeScript, Crystal, SAML, Go
Frameworks
Ruby on Rails (RoR), Capybara, Stimulus, Cypress, AngularJS, React Native, Tailwind CSS, Nuxt.js, Angular
Libraries/APIs
jQuery, React, Stripe API
Tools
Docker Compose, JavaScript Testing, CircleCI, GitHub, RSpec
Paradigms
Test-driven Development (TDD), Continuous Integration (CI), Continuous Deployment, Kanban, Agile, Design Patterns, REST, Web Architecture, Web Application Architecture, Continuous Delivery (CD), Extreme Programming, DevOps, Management
Platforms
Docker, Heroku, Linux, Director, Kubernetes, Amazon Web Services (AWS)
Storage
PostgreSQL, MySQL, Amazon S3 (AWS S3)
Other
Leadership, Lean Development, Team Leadership, Remote Work, Remote Team Leadership, QA Automation, Technical Leadership, APIs, Legacy Code, CTO, Team Mentoring, Architecture, GitOps, Customer Success, Account Management, Infrastructure, Executive Coaching, Agile Leadership, Material Design, Scrum Master, RETS, Agile DevOps, WebSockets, Platform as a Service (PaaS), SAML-auth, Agile Delivery, Agile Coaching, Lean, Engineering, Product Discovery, Stakeholder Management
Education
2002 - 2007
Master's Degree in Applied Mathematics
Donetsk National University - Ukraine
Certifications
NOVEMBER 2012 - PRESENT
Functional Programming Principles In Scala
Coursera
OCTOBER 2012 - PRESENT
Computing For Data Analysis
Coursera
OCTOBER 2012 - PRESENT
Machine Learning
Coursera