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Senior Full-Stack .NET Engineer


We are a healthcare technology services company that helps our customers build world class software. We are proud that our first client is still our client. We trust our teams to deliver without constantly watching over their shoulders. And we have employees who have been with us for more than 15 years. 


We are looking for a talented .NET Engineer to join us in the development of an enterprise healthcare software product for one of our clients – a US-based medical benefits management organization serving both government and commercial clients. You will be part of a scrum team, located in Bulgaria, working with other scrum teams located in the US. Strong collaboration and communication skills will be key for the successful candidate. Our teams are spearheading the development of a cloud native service giving access to over 9 million users to telehealth registered nurses for triage, self-care advice, and general health inquiries 24 hours a day, seven days a week.  

The technology stack includes .NET Core, Angular, Microsoft Azure, Containers (Docker and K8s), PostgreSQL, Event Hub, and Terraform. 


  • Participate in the Design, Implementation, Testing, Deployment, and Maintenance of new and existing data components, microservices, and UI components;
  • Communicate closely with the client and craft backlog;
  • Participate in DevOps processes;
  • Take part in a team that transforms every task into an exciting, valuable experience;
  • Convert business needs into technical implementation.


  • 5+ years of experience developing scalable enterprise solutions;
  • Experienced in all areas of the software development process;
  • Familiar with SOLID principles, Design Patterns and SOA;
  • Technology expert with C#, ASP.NET WebAPI, SQL, CSS and HTML;
  • Experienced in Angular/ReactJs;
  • ny DevOps experience (Azure DevOps, Containers, Terraform, etc.);
  • Passionate – You search relentlessly for the right solution and would like to work with equally passionate people;
  • Humble – Focused more on the team than yourself; ability to disagree but commit to others’ ideas;
  • Hungry – eager to learn, determined to solve problems and get things done;
  • Smart – Intellectually, with an eagerness to learn; but also, emotionally, recognizing team dynamics;
  • Fluent in English.


  • A competitive salary and social benefits;
  • Friendly work environment and nice attitude;
  • Work-life balance;
  • Modern and comfortable office close to the metro station “Konstantin Velichkov”;
  • Opportunities for career development in an international company

Why We Do It? We care.

At OSI, we care about our clients, we care about each other, and we care about producing great software.

CLIENTS — We admit that the organization we most want to see succeed is our own. But we’ll quickly acknowledge that we can’t win unless our clients win. There’s no way around this symbiotic relationship. Fortunately, at OSI, we genuinely love to see our partners have breakthroughs in top-line growth, innovation and efficiency.

TEAM — If you’ve ever experienced the excitement that comes from being part a high-functioning team, you’ll understand why people matter. Trust. Accountability. Purpose. Self-confidence. These are all part of that exhilaration, but the whole is more than the sum of its parts. Great teams can get you through the tough times and can unlock greater potential than a group of individual contributors ever will.

PEOPLE – We care about individuals and humankind. That’s why we invest in talent and push people to do their best work. That’s also why we have given colleagues help when they’ve encountered personal crises; paid for surgeries people couldn’t afford; funded capital improvements and arts projects to improve our communities; and closed the office to attend colleagues’ weddings.

SOFTWARE – We care about the code that we write. We take pride in it. We constantly try to improve on it. We adopt best practices when they suit us. We geek out over data and make it work for us. We are not afraid to try the latest & greatest and to support the last year’s. We are ready to make mistakes and learn from them. We know that building great software requires a lot from us and we committed to it.


If this sounds like you and we look like the kind of people that you would like to work with simply reach out to us with your CV in English and anything else, you are proud of.

All applications will be treated as strictly confidential.
Only short-listed candidates will be contacted.

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