Sasa Cetkovic, Developer in Prague, Czech Republic
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Sasa Cetkovic

Verified Expert  in Engineering

Back-end Developer

Prague, Czech Republic
Toptal Member Since
February 27, 2017

Sasa is an enthusiastic and proactive software developer with professional experience using Microsoft technologies. He adheres to SOLID principles and specializes in C#, Windows services, and RESTful Web APIs. He has done chiefly back-end development but would enjoy stretching out to doing full-stack.


Earthlinktele (via Toptal)
Angular, Web API, .NET Core, .NET
UDS (via Toptal)
C#, Entity Framework, Angular, ASP.NET Core
Authority Partners, Inc.
REST APIs, RESTful Development, jQuery, JavaScript, TFS, Microsoft SQL Server...




Preferred Environment

Git, TFS, Visual Studio Code (VS Code), Visual Studio, MacOS, Windows

The most amazing...

...thing I've developed is a complete back end for a music streaming service.

Work Experience

Software Developer

2017 - 2019
Earthlinktele (via Toptal)
  • Created and maintained Web API services for the support of web and mobile applications.
  • Designed and created a back-end system for a music streaming service.
  • Implemented and extended SSO web service using Identity Server 3 and 4.
  • Maintained a SPA web portal implemented with Angular.
  • Created an internal management website using Angular.
Technologies: Angular, Web API, .NET Core, .NET

Software Developer

2017 - 2017
UDS (via Toptal)
  • Created a web API with data aggregation features.
  • Used Angular Reactive Forms for the front-end input forms.
  • Created data visualizations using Google Charts.
Technologies: C#, Entity Framework, Angular, ASP.NET Core

Software Developer

2015 - 2017
Authority Partners, Inc.
  • Developed business applications for US-based real estate and mortgage companies.
  • Worked on a major re-implementation of background services using WCF and an ESB system.
  • Developed internal high-performance event-logging services using ETW.
  • Maintained XML document processing services that worked with internal and standard MISMO formats.
  • Worked with the Redis cache.
Technologies: REST APIs, RESTful Development, jQuery, JavaScript, TFS, Microsoft SQL Server, ASP.NET MVC, Windows Communication Framework (WCF), Service-oriented Architecture (SOA), C#

Software Developer

2015 - 2016
  • Supported and upgraded an ASP website written in VBScript.
  • Maintained an internal administration website.
  • Implemented a two-factor authentication with SMS or voice calls using Twilio.
  • Transferred incrementally the business logic from the old code to a new background service.
  • Worked in a fast delivery agile environment with individual sprints lasting only a week.
Technologies: VBScript, ASP, jQuery, JavaScript, TFS, Microsoft SQL Server, ASP.NET MVC, ASP.NET Web API, Windows Communication Framework (WCF), C#

Web Developer

2014 - 2015
Freelance Work
  • Developed an advertisement website for public auctions.
Technologies: CSS, HTML, Microsoft SQL Server, ASP.NET MVC, C#

Web Developer

2011 - 2014
Autotehnik D.O.O.
  • Maintained an internal ASP.NET website.
  • Maintained an MS Access application used as a warehouse inventory.
Technologies: CSS, HTML, Microsoft Access, Microsoft SQL Server, ASP.NET, C#

This is a database logger for ASP.NET Core (an implementation of common logging abstractions).


C#, T-SQL (Transact-SQL), TypeScript, XML, HTML, CSS, VBScript, JavaScript


ASP.NET, ASP.NET Core 2, .NET Core, Json.NET, ADO.NET, Windows Communication Framework (WCF), ASP.NET MVC, ASP.NET Web API, .NET, Windows Workflow Foundation, ASP.NET Core, Entity Framework Core, ASP.NET Web Forms, ASP.NET Identity, OAuth 2, Swagger, Windows Presentation Foundation (WPF), Entity, MVC Razor, ASP, Angular, Bootstrap 3, Classic ASP


Entity Framework, Web API, LINQ, Windows Forms (WinForms), REST APIs, Managed Extensibility Framework (MEF), MembershipReboot, Dropbox API, AutoMapper, ETW, jQuery, Redis Queue, Twilio API


Visual Studio, Visual Studio 2019, Azure Key Vault, Microsoft Visual Studio, Azure Logic Apps, Autofac, TFS, Git, Azure DevOps Services, Microsoft Access, Azure Search, Azure App Service, Azure Application Insights, Azure Kubernetes Service (AKS), RabbitMQ, Angular CLI, Postman


Dependency Injection, Object-oriented Programming (OOP), Service-oriented Architecture (SOA), Agile Software Development, Model View Viewmodel (MVVM), Design Patterns, RESTful Development, Microservices Architecture, Scrum


Windows, Azure Functions, Visual Studio 2017, MacOS, Visual Studio Code (VS Code), Azure Event Hubs, Azure Service Fabric, Azure


Identity Server, Azure WebJobs, Azure Virtual Machines, OWIN, Multithreading, SOLID Principles, Azure Service Bus, Azure Virtual Networks, IIS,


Azure Blobs, Azure Cache, Azure Cosmos DB, Azure SQL, Microsoft SQL Server, MySQL, Azure Queue, Azure Tables, Azure Active Directory, Azure Table Storage, PostgreSQL, Amazon S3 (AWS S3)

2007 - 2013

Bachelor's Degree in Software Engineering

University Džemal Bijedić, Faculty of Information Technologies - Mostar, Bosnia and Herzegovina

JULY 2020 - JULY 2022

Azure Developer Associate