Open to opportunities

Oscar Quesada Avalos

@oscarquesadaavalos

Senior .NET developer specializing in API architecture, clean engineering, performance tuning, and production reliability.

Costa Rica

Message

What I'm looking for

I’m looking for a role where I can modernize and architect .NET APIs with SOLID principles—owning performance, reliability, and testing quality—while collaborating with product/UX and shipping through strong CI/CD in cloud environments.

I’m a Senior .NET Engineer with 15+ years designing, modernizing, and operating enterprise web applications and API-driven systems. I build with C#, ASP.NET MVC/Core, .NET Framework, SQL Server, and REST services, delivering cloud-ready products across Azure and AWS.

I’m known for clean architecture and SOLID engineering, plus performance optimization and production reliability. In one case, I reduced a high-volume annual processing workflow of 1.3M+ records from hours to under 5 minutes through MVC/Web APIs/REST query and data-processing improvements.

I focus on engineering quality and confidence: I raised automated test coverage above 80% using xUnit, NUnit, Selenium, and Playwright. I also built a monthly synchronization engine in C# using LINQ, pagination, and SQL Server to bring execution time to under 3 minutes while preserving traceability and data integrity.

I collaborate closely with product owners, designers, UX teams, and distributed Agile engineering groups. From backend modernization to observability and DevOps-friendly delivery, I turn requirements into maintainable features and reliable releases through SOLID patterns, refactoring, and strong operational practices.

Experience

Work history, roles, and key accomplishments

Current

Senior .NET Developer

Current

Novacom - INS

Jul 2024 - Present (2 years)

Modernized legacy enterprise modules and backend workflows using C#, .NET Framework/.NET Core, Blazor, MVC/WebForms patterns, and SQL Server. Refactored code to address SonarQube issues and expanded automated test coverage with xUnit, NUnit, Selenium, and Playwright.

C#.NET Framework .NET Core Blazor MVC SQL Server Azure Pipelines xUnit NUnit Selenium Playwright SonarQube Splunk LINQ REST

Senior Software Engineer

Tridius Technologies

May 2022 - Jul 2024 (2 years 2 months)

Architected and implemented scalable cloud-based, API-driven services using C#/.NET and AWS. Built distributed systems for high availability, performance, and secure authentication/authorization, and mentored engineers.

C#.NET Core .NET Framework AWS Lambda SQS SNS EC2 S3 Docker Azure Azure DevOps SAML OAUTH2 JWT Angular Authentication Authorization

Software Engineer / DevOps

GFT Group

Jul 2021 - May 2022 (10 months)

Implemented monitoring and observability across React frontends, .NET backend APIs, and cloud infrastructure. Automated operational and deployment workflows and collaborated with Agile teams to stabilize applications and improve maintainability.

C#.NET Core .NET Framework ASP.NET Core MVC React AWS Jenkins Docker Azure Key Vault Monitoring SQL Server T SQL Stored Procedures ETL Performance Agile

Frontend DevOps Engineer

Encora Inc.

Aug 2020 - Jul 2021 (11 months)

Managed Azure infrastructure, identity, networking, and secure configurations for enterprise application environments. Automated deployments and operational workflows with PowerShell and CI/CD pipelines, and migrated on-premises SQL Server to Azure SQL.

Azure Azure AD SQL Server Azure SQL PowerShell CI CD Azure DevOps GitHub Actions Docker Jenkins Security React TypeScript Blazor Angular Playwright SonarQube Splunk

Team Lead .NET Production Support

Encora Inc.

Jul 2019 - Aug 2020 (1 year 1 month)

Led backend/API support and release management for .NET APIs, integrations, and database components to ensure service continuity. Coordinated on-call and automation/operational improvement initiatives to increase stability.

C#.NET LINQ Entity Framework SQL Server APIs Integration Production Support Release Management Automation

Senior Software Developer

JMD Mobile Solutions / EagleView

Oct 2018 - Jun 2019 (8 months)

Developed web and mobile-oriented application components using .NET and supporting technologies. Supported cross-platform development and integrations for distributed application environments.

.NET C#Golang Objective C PostgreSQL Linux AWS

Technical Consultant .NET

Quenti Technologies / Sysde

Feb 2015 - Oct 2018 (3 years 8 months)

Built enterprise web applications in C# and .NET Framework using layered architecture concepts, LINQ, generics, and MVC/Web API. Integrated backend systems using WCF and REST services/JSON APIs with MongoDB and Azure-based infrastructure.

C#.NET Framework MVC Web APIs LINQ Generics WCF REST APIs SQL Server MongoDB Azure Performance

Software Engineer / DevOps Engineer

TradeStation

Aug 2015 - May 2018 (2 years 9 months)

Developed backend business logic and integrations for Dynamics CRM using .NET and T-SQL. Managed production releases and supported SQL Server operations including jobs, SSIS, SSRS, failovers, maintenance, and troubleshooting.

.NET T SQL SQL Server SSIS Dynamics CRM Production Releases Agile Stored Procedures Maintenance

Computer System Analyst / Quality Mgr

ACORDE

Jan 2012 - Jan 2015 (3 years)

Developed enterprise web applications and supported service desk and release processes aligned with ITIL. Worked with C#/.NET, MVC, IIS, WCF/ASMX services, SQL Server/Oracle, and reporting tools.

C#.NET MVC SQL Server Oracle IIS WCF Crystal Reports SSIS ITIL Service Desk

Early .NET / QA Support

Prosoft / Sysde / Coopecaja

Jan 2009 - Jan 2012 (3 years)

Provided early .NET and QA support, including database support and stored procedures, plus XML reporting and migration-related work. Contributed to regulatory reporting systems.

.NET & QA Database Support Stored Procedures Oracle Forms Regulatory Reporting