Middle/Senior Typescript/Node.js Developer with AI experience (AdTech)

Are you passionate about building intelligent, scalable, and high-performance platforms powered by AI technologies? Sigma Software is seeking a Middle/Senior AI & Back-End Developer to transform a global AdTech product into a modern AI-enabled ecosystem. The role involves working with cloud-native and AI technologies in a Platform-First architecture featuring reusable microservices and serverless infrastructure. The customer is a Sweden-based AdTech company serving globally recognized publishers and brands like TripAdvisor and Bloomberg, processing millions of advertising transactions worldwide.

• 7+ years of commercial experience as a Back-end Developer
• Strong hands-on experience with TypeScript and Node.js
• Experience building API-first microservice architectures
• Practical experience integrating AI services, LLM APIs, or AI-assisted workflows
• Hands-on experience with AWS serverless technologies including Lambda, API Gateway, DynamoDB, and EventBridge
• Understanding of RESTful and GraphQL APIs
• Knowledge of prompt engineering concepts and AI integration approaches
• Understanding of multi-tenant architectures and logical data isolation principles
• Interest in AdTech products, automation, and AI-driven optimization
• Upper-Intermediate or higher English level

Nice to have:

• Experience with ML and AI experimentation projects
• Exposure to recommendation systems or data intelligence platforms
• Experience working with vector databases
• Familiarity with Infrastructure as Code tools such as Terraform or CloudFormation
• Understanding of observability and monitoring practices in distributed systems
• Experience working with scalable cloud-native architectures

• Develop and maintain high-performance Back-end microservices and AI-enabled services using TypeScript and Node.js
• Design, implement, and integrate AI and LLM-powered platform features
• Build scalable serverless solutions using AWS Lambda, API Gateway, DynamoDB, and EventBridge
• Collaborate with cross-functional teams on API-first architecture and OpenAPI specifications
• Ensure tenant data isolation and compliance with established AdTech data models
• Contribute to reusable libraries, templates, AI integration patterns, and engineering standards
• Participate in code reviews focused on performance, reliability, observability, and service quality
• Translate product and AI feature requirements into scalable technical solutions
• Support the platform transformation toward automation, standardization, and intelligent reusability
• Contribute to continuous improvement initiatives and technical decision-making processes