Sebastian Colbert, Developer in Southington, CT, United States
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Sebastian Colbert

Verified Expert  in Engineering

Android Developer

Southington, CT, United States
Toptal Member Since
August 20, 2019

Native Android development is what Sebastian enjoys most. With 20 years of software development experience across various types of industries, Sebastian brings organization and stability to the project. His uncommon ability to seamlessly translate business asks into technical requirements guarantees a satisfied client. Sebastian has had many lead roles, which he relishes, but he will happily contribute as an individual developer or team member.


Android Jetpack, Google Play Store, Team Leadership, Leadership...
InteleXual Software LLC
Kotlin, XML, GitLab, MacOS, Android, Jetpack Compose, Programming...
Pentius (via Toptal)
Android Jetpack, Coroutines, Mobile Apps, Model View ViewModel (MVVM)...




Preferred Environment

Git, Android Studio, MacOS, Android, Kotlin, Flutter, Dart

The most amazing...

...thing I've done was develop an Android Compose app for the U.S. Army's Black Hawk program with a clean design, smooth UI, and fast performance.

Work Experience

Android and iOS Tech Lead

2013 - PRESENT
  • Worked as an Android tech lead for Cigna's Android mobile development team.
  • Spearheaded projects in an agile environment for Cigna's flagship mobile app, "myCigna," and other apps.
  • Guided and developed various features and improvements for "myCigna" and other apps.
  • Oversaw managing and publishing Cigna-branded apps in Google Play and Amazon stores.
  • Facilitated business and technical requirements between the customer, technical teams, and management.
  • Created new processes to facilitate more efficient development and interaction between developers.
  • Improved software quality and reduced delivery and maintenance costs through innovative methods.
Technologies: Android Jetpack, Google Play Store, Team Leadership, Leadership, Bluetooth Beacons, Coroutines, Mobile Apps, Model View ViewModel (MVVM), Mobile Architecture, RESTful Development, Technical Project Management, Project Leadership, REST APIs, Firebase, SQLite, Android Architecture, Android Studio, Agile, Project Management, REST, Git, Gradle, Kotlin, Java, Android, Mobile, Bluetooth LE, Android App Design, Bluetooth, Mobile App Development, Remote Team Leadership, WebView, Jetpack Compose, Healthcare Software, Fast Healthcare Interoperability Resources (FHIR), Programming, Software Design, GitLab, SDKs, Software Architecture, Mobile Development, Android SDK, Auth0, Native Mobile Apps, UI Development, Crashlytics, Technical Leadership, MacBook


2023 - 2023
InteleXual Software LLC
  • Developed a "Flight Crew Operating Manual" (FCOM) Android application for the U.S. Army's Black Hawk helicopters.
  • Designed an application using clean architecture for better app performance and maintainability.
  • Advised on UI design improvements for better end-user usability.
Technologies: Kotlin, XML, GitLab, MacOS, Android, Jetpack Compose, Programming, Software Design, SDKs, Software Architecture, Mobile Development, Android SDK, Native Mobile Apps, UI Development, MacBook


2020 - 2020
Pentius (via Toptal)
  • Led discussions with business partners on mobile approach and implementation.
  • Architected credit report module using data from TransUnion, Experian and Equifax.
  • Developed Android implementation of the report module.
Technologies: Android Jetpack, Coroutines, Mobile Apps, Model View ViewModel (MVVM), Mobile Architecture, RESTful Development, Technical Project Management, Project Leadership, Retrofit, Android Architecture, Android Studio, Project Management, Git, Gradle, Retrofit 2, REST APIs, REST, Kotlin, Android, Mobile, Android App Design, Mobile App Development, Programming, Software Design, GitLab, SDKs, Software Architecture, Mobile Development, Android SDK, Native Mobile Apps, UI Development, MacBook


2013 - 2013
Solution Innovators
  • Facilitated the completion of an overdue project and upgraded the design and technology to industry standards.
  • Researched about mobile platforms for new client projects.
  • Provided advice on new project architecture for web-based applications.
Technologies: Apache Tomcat, MySQL, CSS, HTML, JavaScript, Java, Jakarta EE, Jakarta Server Pages (JSP), Programming, Software Design, Software Architecture


2011 - 2012
  • Converted a Swing application to JSF to improve performance, maintenance, and overall user experience.
  • Implemented a web service module to facilitate the archival of video clips.
  • Developed an FTP module, as part of my core services, for handling various video requests used by the entire company.
  • Executed the implementation of the “Media Orchestration Engine” API to assist with the submission of workflows and reduce manual processing costs.
Technologies: Enterprise Java Beans (EJB) 3, Jakarta Server Pages (JSP), Agile, MySQL, Oracle, SQL, REST, Web Services, Apache Tomcat, CSS, HTML, Java, Enterprise Java Beans (EJB), Jakarta EE, JSF, Programming, Software Design, Software Architecture

Tech Lead

2006 - 2011
Sikorsky Aircraft
  • Architected and implemented the Sikorsky360 portal for commercial and military aircraft owners to centralize critical maintenance tools that keep aircraft flying.
  • Planned, implemented, and maintained a production-level infrastructure for the Sikorsky360 portal based on VMware technology.
  • Drafted and implemented various web applications for both internal and external customers to maximize customer's processes' efficiency, usability, and accountability.
  • Provided ongoing advice on technology selection, planning, implementation, and cost savings.
Technologies: Team Leadership, Leadership, Servlet, Architecture, Technical Project Management, Project Leadership, Web Services, Jakarta Server Pages (JSP), SQL, Project Management, VMware, Apache Tomcat, Apache, Oracle, CSS, HTML, JavaScript, Java, JSF, Jakarta EE, Programming, Software Design, Software Architecture, Technical Leadership

Senior Analyst, IT Systems Design

2003 - 2006
Sikorsky Aircraft
  • Designed and implemented a fleet-monitoring-service portal for commercial aircraft owners to help maintain and diagnose aircraft.
  • Managed critical production servers which hosted commercial web applications.
  • Drafted and executed a procedure for configuring and cloning laptop ground stations for each delivery to the customer of S-92 aircraft.
  • Developed a web-based plug-locator application that assisted mechanics in finding electrical plugs on the aircraft.
  • Configured and presented future and new product demonstrations for presidential, military, and commercial customers.
  • Worked with multiple third-party vendors to integrate the software with various interfaces into functional systems.
Technologies: Servlet, JSF, Apache, Apache Tomcat, Web Services, SQL, Java, Oracle, XML, CSS, HTML, JavaScript, Jakarta Server Pages (JSP), Java Servlets, Jakarta EE, Programming, Software Design

Computer Systems Programmer | Analyst | Team Leader

1999 - 2003
Computer Sciences Corporation
  • Designed and implemented a work-in-progress web app that produced manufacturing reports.
  • Developed web-based productivity reports for management use.
  • Designed and created a file management interface for robot programs.
  • Created a perishable tool forecasting web application.
  • Led a team that developed a business-metric-tracking web application.
  • Built an intranet reporting web application for multiple browsers.
  • Designed and created an interactive online newsletter.
  • Drafted and implemented an intranet website for the entire product center.
  • Worked with a team to produce a web application for generating work instructions.
  • Created many other applications with Java, Servlets, JSP, Visual Basic, MS Access, and BusinessObjects with a focus on owning the customer rather than just the application.
Technologies: Team Leadership, Leadership, Technical Project Management, Project Leadership, SQL, Project Management, Perl, Oracle, XML, CSS, HTML, JavaScript, Java, Jakarta Server Pages (JSP), Java Servlets, Jakarta EE, Enterprise Java Beans (EJB), Programming, Software Design, Technical Leadership

Junior Computer Systems Programmer | Analyst

1998 - 1999
Pratt & Whitney
  • Built and enhanced an oven-monitoring system application.
  • Developed and enhanced a company-wide server-client menu system.
  • Optimized an application for generating work instructions.
  • Generated online application documentation as one of the first in the company to do so.
Technologies: Oracle, SQL, HTML, Visual Basic, Java, Programming, Software Design

Member of the Military Police

1993 - 1999
Connecticut Army National Guard
  • Earned an honor graduate status at military police school.
  • Commanded a squad of 12 soldiers plus a platoon as needed.
  • Achieved five awards, including a non-commissioned officer professional development ribbon.
Technologies: Team Leadership, Leadership, Military

Polka Polka | Android App
I created a personal app called Polka Polka which allows you to stream Polish and other types of music to your phone or tablet. There are several stations to choose from for your listening or dancing enjoyment.

Highlighted Features:
• Select and filter your favorite stations.
• Switch between light and dark themes.
• Play music in the background while you do other tasks.

Silver Change | Android App
I created a personal app called Silver Change. The value of the dollar has steadily declined since 1913 when the Federal Reserve was created. The process has accelerated in 1971 when President Nixon took the US off of the gold standard. While nominal dollar value decreased, coins made with silver, commonly called "junk silver," retained their value.

The app is a virtual wallet where a user can select the silver coins and quantities and see the total real value based on metal content. The nominal value is shown as well. Each coin also has a description, metal content information, and historical notes.

Android Video Lessons

I created an educational website for learning Android. The website focuses on short topics so users can watch and apply them immediately. The lessons cover a range of topics on UI components for Android.

Co-inventor for Patent No. US 7,983,809 B2
An aircraft-integrated support system (ISS) downloads integrated vehicle health management system (IVHMS) data from an aircraft, processes the downloaded data to infer a status of aircraft systems, and displays maintenance information via an interactive electronic technical manual (IETM).
2002 - 2004

Master of Science (MSc) Degree in Management

Rensselaer Polytechnic Institute - Hartford, CT, USA

2000 - 2001

Master of Science (MSc) Degree in Internet Engineering

Marlboro College Graduate and Professional Studies - Brattleboro, VT, USA

1994 - 1998

Bachelor of Science (BSc) Degree in Computer Science

Central Connecticut State University - New Britain, CT, USA


Retrofit 2, REST APIs, Retrofit, Java Servlets


Android Studio, WebView, GitLab, Auth0, Android Jetpack, Servlet, Git, Gradle, Crashlytics, Apache Tomcat, Apache, VMware


Android SDK, Flutter, JSF, JavaServer Faces, Jakarta Server Pages (JSP)


Java, Kotlin, HTML, Dart, XML, CSS, SQL, Perl, Visual Basic, JavaScript


Model View ViewModel (MVVM), RESTful Development, REST, Agile, Mobile Development, Fast Healthcare Interoperability Resources (FHIR), Cross-platform, Web App Design


Android, Mobile, MacOS, Oracle, Firebase, Jakarta EE, Bluetooth LE, iOS

Industry Expertise

Project Management




Mobile Architecture, Mobile Apps, Leadership, Team Leadership, Remote Team Leadership, Google Play Store, Project Leadership, Technical Project Management, Android App Design, Mobile App Development, IT Project Management, Programming, Software Design, Jetpack Compose, Healthcare Software, Healthcare & Insurance, SDKs, Software Architecture, Native Mobile Apps, UI Development, Technical Leadership, MacBook, Coroutines, Android Architecture, Architecture, Military, Bluetooth Beacons, Web Services, Enterprise Java Beans (EJB) 3, Enterprise Java Beans (EJB), Bluetooth, Business Cases, Finance, Networks, eCommerce, Algorithms

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