Hi, I’m Nikola Rajkovic, a versatile Senior Full Stack Engineer with 10 years of experience designing and building enterprise applications using .NET, Angular, and AWS. I thrive on crafting backend services, scalable frontends, and secure cloud deployments, and I enjoy turning complex requirements into robust, high-uptime systems. I also integrate AI into production workflows, building LLM-assisted solutions with Python, document-based RAG pipelines, and vector search workflows. I’m comfortable in Agile environments and regulated settings, and I enjoy mentoring teammates and shaping architecture decisions for scalable systems. Outside of core development, I collaborate across teams to deliver rapid prototyping, A/B testing, and production-grade AI/LLM integrations that elevate user experiences.

Nikola Rajkovic

Hi, I’m Nikola Rajkovic, a versatile Senior Full Stack Engineer with 10 years of experience designing and building enterprise applications using .NET, Angular, and AWS. I thrive on crafting backend services, scalable frontends, and secure cloud deployments, and I enjoy turning complex requirements into robust, high-uptime systems. I also integrate AI into production workflows, building LLM-assisted solutions with Python, document-based RAG pipelines, and vector search workflows. I’m comfortable in Agile environments and regulated settings, and I enjoy mentoring teammates and shaping architecture decisions for scalable systems. Outside of core development, I collaborate across teams to deliver rapid prototyping, A/B testing, and production-grade AI/LLM integrations that elevate user experiences.

Available to hire

Hi, I’m Nikola Rajkovic, a versatile Senior Full Stack Engineer with 10 years of experience designing and building enterprise applications using .NET, Angular, and AWS. I thrive on crafting backend services, scalable frontends, and secure cloud deployments, and I enjoy turning complex requirements into robust, high-uptime systems. I also integrate AI into production workflows, building LLM-assisted solutions with Python, document-based RAG pipelines, and vector search workflows.

I’m comfortable in Agile environments and regulated settings, and I enjoy mentoring teammates and shaping architecture decisions for scalable systems. Outside of core development, I collaborate across teams to deliver rapid prototyping, A/B testing, and production-grade AI/LLM integrations that elevate user experiences.

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Experience Level

Expert
Expert
Expert
Expert
Expert
Expert
Expert
Expert
Expert
Expert
Expert
Expert
Expert
Expert
Expert
Expert
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Language

English
Fluent

Work Experience

Senior Software Engineer, Technical Lead at EMIS Group
June 1, 2019 - November 1, 2025
Led architecture and development of an AI-powered medical conference and workflow platform using C#, ASP.NET Core, Angular, and AKS, ensuring FHIR/HL7/X12 compliance. Built a billing and claims system handling 100k+ concurrent requests using REST, gRPC, Azure Service Bus, and Azure OpenAI for automated claim validation. Improved SQL Server performance by 20% through indexing and query optimization. Upgraded frontend modules to modern Angular and introduced real-time notifications with SignalR. Automated Dynamics 365 workflows with Power BI and SharePoint integrations, strengthened security with Azure Key Vault and RBAC/ABAC, and delivered CI/CD pipelines with Azure DevOps/Jenkins.
Senior Software Engineer at Codolis
February 1, 2017 - June 1, 2019
Mentored junior engineers and led system design reviews. Migrated legacy genetic testing systems into .NET Core microservices, React/Next.js-based frontend, and Docker, reducing processing time by 35%. Implemented modular microfrontends, optimized SQL/EF Core queries for speed, and automated SSO/MFA migration to Azure AD for 500+ users. Integrated Dynamics 365 with internal systems to improve data sync by 15%. Built ETL pipelines in Databricks (PySpark/Scala) and implemented Datadog monitoring. Delivered Azure solutions including Service Bus, Functions, VMs, and AKS.
Software Engineer at Protech Ltd.
September 1, 2015 - February 1, 2017
Built scalable backend services with ASP.NET Web API and PostgreSQL for 100k+ users. Developed 30+ Next.js + TailwindCSS pages for a medical management system. Created C# SDKs for Stripe payment workflows. Mentored junior developers in API design and .NET best practices. Designed cloud monitoring solutions using AWS CloudWatch, DynamoDB, and PostgreSQL.
Senior Full Stack Engineer at BCG Digital Ventures
January 1, 2022 - Present
Led the development of enterprise-grade SaaS platforms using C#/ .NET Core APIs and Angular frontends, ensuring modular architecture, high uptime, and multi-tenant support across a global user base. Built dynamic UI components in Angular, integrated with secure REST APIs, and enabled real-time collaboration with SignalR and WebSockets. Architected AI-powered assistants using Python (FastAPI) with OpenAI and LangChain for document-based RAG pipelines and vector search with Pinecone. Implemented RBAC and ABAC across APIs and UI layers using JWT and OAuth2, deployed infrastructure with Terraform on AWS, and created CI/CD pipelines with GitHub Actions. Optimized SSR with Angular Universal and API-level caching for SEO-friendly pages, and collaborated on internal tooling with React/Next.js for rapid prototyping and A/B testing.
AI Software Engineer at EMIS
June 1, 2019 - November 1, 2021
Developed healthcare applications using .NET Core APIs and Angular dashboards to support clinical workflows and data-driven decision-making. Created Python AI modules (Hugging Face Transformers) for document classification, prescription parsing, and summarization, and built FHIR-compliant data ingestion pipelines connected to NHS APIs and EHR systems. Ensured data privacy with encrypted AWS storage, KMS-based key management, and secure REST endpoints; containerized services with Docker and AWS ECS; Jenkins pipelines for CI/CD; and cross-functional collaboration in Agile teams to integrate AI into enterprise architectures.
Full Stack Developer at Codolis
February 1, 2017 - June 1, 2019
Delivered large-scale e-commerce platforms using .NET MVC and Angular, implementing modular dashboards, shopping flows, and secure checkout for B2C/B2B. Introduced AI-driven product tagging and category suggestions using Python (Flask) and ML models, and migrated UI from jQuery to modern Angular. Built backend microservices for inventory, orders, and third-party vendor integrations; implemented real-time notifications with SignalR and integrated with service workers for engagement; led CI pipelines with Jenkins and defined release processes across teams.
Backend Developer at Protech
September 1, 2015 - February 1, 2017
Developed REST APIs using .NET Web API and Django modules for real estate and education portals, including file management, quizzes, grading, and progress reporting. Built media delivery tools with Django, managed access control and metadata tagging, improved API performance with optimized SQL Server queries, added Redis caching, and implemented diagnostic logging. Wrote integration tests to verify data contracts between React frontends and .NET/ Django services, and supported frontend teams with debugging and mocks. Participated in Agile ceremonies and contributed to backend architecture decisions.

Education

Bachelor of Science (B.S.) in Computer Engineering at University of Belgrade
January 1, 2011 - January 1, 2015
Bachelor of Science in Computer Science at University of Belgrade
January 1, 2011 - January 1, 2015

Qualifications

AWS Certified Solutions Architect
December 1, 2024 - February 17, 2026
Scrum Master Certified
October 1, 2023 - February 17, 2026

Industry Experience

Software & Internet, Healthcare, Financial Services, Professional Services, Education, Media & Entertainment