Sergio (Rangel) Rangel Alvarez-Fullstack Developer
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Experience
Fullstack Developer
BusinessOne
- Developed a base application with shared core functionalities, enabling us to build four web applications simultaneously with a small development team.
- Leveraged the latest .NET technologies to implement efficient and modern solutions.
- Applied Domain Driven Design (DDD) to achieve greater code organization and reusability, optimizing development time.
- Implemented unit testing to enhance code stability and reliability.
- Three of the four applications are currently live in production.
- Technologies: C#, .NET Core, Blazor, Entity Framework, SQL Server, MudBlazor, Bootstrap
Mobile Application Developer
GSoft Innovation
- Designed and developed multiple cross-platform mobile apps for Android and iOS using Flutter.
- Designed CI/CD pipelines to automate deployment and reduce delivery time.
- Applied Domain Driven Design (DDD) to improve code structure, maintainability, and efficiency.
- Implemented unit tests to increase system reliability.
- Technologies: Flutter, Dart, Bloc, Firebase, Google Maps API, GraphQL, RESTful API, Material UI, Kotlin, Swift
Consol Freight / Geolocation System
Consol Freight LLC
- Developed a web application to optimize maritime cargo transport routes using Dijkstra’s algorithm.
- Achieved 90% unit test coverage, resulting in a robust and reliable solution currently in use.
- Technologies: React, .NET, JavaScript, C#, RESTful API, Redux
Industry experience
See where this freelancer has spent most of their professional time.
Experienced in Information Technology and Transportation.
Business area experience
See which departments and functions this freelancer has contributed to most.
Experienced in Information Technology, Product Development, and Quality Assurance.
Summary
I am a Computer Scientist with over six years of experience in web and mobile application development. I apply the most up-to-date techniques in both fields and am passionate about programming and best practices. I have hands-on experience with programming languages such as C#, Dart, JavaScript, and Python, and frameworks such as .NET, Flutter, React, and React Native. I am a fast learner, hard-working, and experienced in time management and teamwork, with strong interpersonal and professional communication skills.
Skills
- Programming Languages: Advanced: Dart, C#; Intermediate: Python, Javascript, Typescript; Basic: C++, Kotlin.
- Frameworks & Tools: Advanced: Flutter, Blazor, .Net; Intermediate: React, React Native.
- Databases: Sql Server, Mysql, Sqlite.
- Agile Methodologies: Scrum.
Languages
Education
University of Havana
Bachelor’s degree · Computer Science · Havana, Cuba
Statistics
Experience
Expertise
Qualifications
Profile
Frequently asked questions
Have questions? Find more information here.
Sergio is based in Paramaribo, Suriname.
Sergio speaks the following languages: Spanish (Native), English (Advanced).
Sergio has at least 9 years of experience. During this time, Sergio has worked in at least 3 different roles and for 3 different companies. The average length of individual experience is 3 years and 10 months. Note that Sergio may not have shared all experience and actually has more experience.
Based on recent experience, Sergio would be well-suited for roles such as: Fullstack Developer, Mobile Application Developer, Consol Freight / Geolocation System.
Sergio's most recent position is Fullstack Developer at BusinessOne.
In recent years, Sergio has worked for BusinessOne and GSoft Innovation.
Sergio is most experienced in industries like Information Technology and Transportation.
Sergio is most experienced in business areas like Information Technology, Product Development, and Quality Assurance.
Sergio has recently worked in industries like Information Technology.
Sergio has recently worked in business areas like Information Technology, Product Development, and Quality Assurance.
Sergio holds a Bachelor in Computer Science from University of Havana.
The availability of Sergio needs to be confirmed.
Daily rate distribution
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Average rates for similar positions
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The average daily rate is the mean of all daily rates from recent contracts of comparable freelancers on our platform.
The median daily rate is the middle value of all daily rates — half of comparable freelancers charge less, half charge more. Unlike the average, it is barely affected by outliers.
Calculated based on our freelancers’ daily rates as of 29 Aug 2026. Actual rates may vary depending on seniority level, experience, skill specialization, project complexity, and engagement length.
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