About Cristopher
Senior .NET Backend Developer and Solution Architect with strong experience building and maintaining mission-critical enterprise systems and scalable integration platforms. I work with .NET Framework, .NET 7, and .NET 8, delivering REST and SOAP APIs, complex business logic in layered architectures, and secure solutions with JWT/RBAC.
I have solid data experience using SQL Server, ADO.NET, Entity Framework (EF6/EF Core), focused on performance (caching, query optimization) and production reliability (monitoring/troubleshooting with Datadog, structured logging). I also build asynchronous and scheduled processing with RabbitMQ, Quartz.NET, and Hangfire, and supports delivery pipelines with GitLab CI/GitHub Actions, Docker testing, and deployments to Kubernetes (AWS EKS) with ArgoCD.
As a freelancer, I design and develop PMS-Integration solutions for the hospitality industry, connecting external PMS providers and satellite services (e-signature, analytics, messaging, document processing) into a standardized domain model and unified API, prioritizing scalability, resilience, and clean architecture principles.
English
Native or bilingual
Spanish
Native or bilingual
Remote only
Primarily works remotely
Experience
- SageSenior DeveloperApril 2025 - Today (1 year and 2 months)• ● Backend Development & Maintenance for a Mission-Critical Enterprise CRM• ● Developed and maintained backend services in .NET Framework 4.8 and .NET 7.0 for a multi-tenant, mission-critical CRM platform.• ● Implemented SOAP and REST APIs to integrate with multiple clients, ensuring backward compatibility and high availability (99.9% SLA).• ● Designed and implemented complex business logic in a layered architecture (API, Services, DAL) using patterns such as Repository, Service Layer, Facade, and Cache-Aside.• ● Built the data access layer using ADO.NET and Entity Framework 6.4.4, enforcing parameterized queries to prevent SQL injection vulnerabilities.• ● Improved performance through in-memory caching strategies and efficient SQL Server connection pool management.• ● Integrated with external cloud services (AWS S3, Lambda, SNS, KMS, Textract; Microsoft Graph API; Google Drive; Dropbox) for document management and storage.• ● Implemented JWT-based authentication and authorization• ● Developed batch processes and scheduled jobs using Quartz.NET and RabbitMQ for asynchronous operations and notifications.• ● Managed tenant-specific database schemas in a multi-tenant architecture using adapters and dynamic query-building strategies.• ● Implemented CI/CD pipelines with GitLab CI and GitHub Actions, automating builds, Docker-based testing (Windows Containers), and deployment to Kubernetes (AWS EKS) via ArgoCD.• ● Developed unit and integration tests, achieving code coverage with Coverlet and generating JUnit/Cobertura reports.• ● Monitored and troubleshot production systems using Datadog APM, adding custom traces and structured logging with NLog.• ● Collaborated on a SCIM 2.0 API (.NET 7.0) for identity management and user provisioning, integrating OAuth 2.0.• ● Refactored legacy code (VB.NET / Singleton pattern) toward modern patterns with dependency injection, maintaining system stability.
- Freelancer (Self-Employed)Technology ConsultantJanuary 2024 - Today (2 years and 5 months)• ● PMS-Integration is a hospitality-oriented integration platform whose main responsibility is to connect multiple external PMS/providers (and satellite services such as e-signature, biometrics, analytics, messaging, etc.) with a standardized internal model and a unified API.• ● As the architect and developer, the project goals are:• ● Normalize heterogeneous data from different providers (bookings/reservations, guests, clients, spaces, etc.) into a shared domain model.• ● Orchestrate synchronizations (on-demand and/or recurring) that call external APIs, transform the data, and persist it.• ● Expose REST endpoints following clear and consistent conventions so other microservices or frontends can consume standardized data.• ● Ensure resilience against external failures (retries, queues, background jobs, logging, and traceability).• ● Maintain an architecture designed to scale across providers and evolve the domain without tight coupling between layers.• ● In practice, the system acts as a connector/data aggregator: it performs a lightweight ETL (extract-transform-load) from external PMS systems and makes data ready for internal consumption, minimizing vendor lock-in.
- WinSystemsSenior DeveloperVIDEO GAMES AND ANIMATIONJanuary 2023 - April 2025 (2 years and 3 months)Barcelona, Spain• ● Build API Rest in .net 6 for a lottery system that works as an integrator between the IPLS system (Internet Paytronic Lottery Systems) and the PLS (Paytronic Lottery System), which is the core of the business where everything related to lottery games is managed. lottery.• ● Service migration from .net framework to .net 6.• ● Homologation of environments between development and staging.• ● Continuous development and partial deliveries of the backend that supports the lottery system in South Africa, Botswana and Uganda.• ● Refactoring of the notification module using factory and SOLID principles.• ● Development functions and stored procedures in SQL Server for the IPLS (Internet Paytronic Lottery Systems) backoffice reporting module.• ● Build API .net core 2.1 that integrates with the terminal's Linux drivers to control the printer and scanner functionalities for reading betslips and subsequently return specific actions via websockets.
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Education
- Master's degreeUCAB.2011Master's degree
- System EngineerUniversidad Nacional Experimental Politécnica de la Fuerza Armada Nacional.2005Bachelor of Science