Middle TypeScript / Node.js Developer with AI Experience

Company Description Are you passionate about building intelligent, scalable, and high-performance platforms powered by AI technologies? We are looking for a Middle/Senior AI & Back-End Developer to join Sigma Software and contribute to the transformation of a global AdTech product into a modern AI-enabled ecosystem. In this remote-friendly role, you will work with cutting-edge cloud-native and AI technologies, helping shape a Platform-First architecture built around reusable microservices, serverless infrastructure, and intelligent automation capabilities. We at Sigma Software value engineering excellence, innovation, and collaboration. You will have an opportunity to work on a product trusted by globally recognized publishers while growing your expertise in AI integrations, cloud platforms, and scalable distributed systems. CUSTOMER Our Customer is a Sweden-based AdTech company specializing in advanced self-serve advertising platforms that automate direct transactions between advertisers and premium global publishers. Their solutions improve transparency and operational efficiency in digital advertising and are trusted by globally recognized brands such as TripAdvisor, Bloomberg, The Washington Post, Opera, and Dow Jones. The company processes millions of advertising transactions worldwide and actively invests in AI-driven automation and intelligent data capabilities. PROJECT The project focuses on the strategic transformation of an existing AdTech ecosystem toward a Platform-First, AI-enabled architecture. The Customer is transitioning from monolithic and client-specific implementations into a scalable, API-driven, multi-tenant ecosystem powered by reusable microservices and intelligent services. The team is building modern cloud-native solutions using AWS serverless technologies while introducing AI-assisted automation, recommendation systems, workflow optimization, data enrichment, and LLM-powered capabilities across the advertising lifecycle. Key Technologies: TypeScript, Node.js, AWS Lambda, API Gateway, DynamoDB, EventBridge, OpenAI APIs, GraphQL, RESTful APIs, Terraform, CloudFormation, Vector Databases Job Description Develop and maintain high-performance Back-end microservices and AI-enabled services using TypeScript and Node.jsDesign, implement, and integrate AI and LLM-powered platform featuresBuild scalable serverless solutions using AWS Lambda, API Gateway, DynamoDB, and EventBridgeCollaborate with cross-functional teams on API-first architecture and OpenAPI specificationsEnsure tenant data isolation and compliance with established AdTech data modelsContribute to reusable libraries, templates, AI integration patterns, and engineering standardsParticipate in code reviews focused on performance, reliability, observability, and service qualityTranslate product and AI feature requirements into scalable technical solutionsSupport the platform transformation toward automation, standardization, and intelligent reusabilityContribute to continuous improvement initiatives and technical decision-making processes Qualifications 3+ years of commercial experience as a Back-end Developer or AI Software DeveloperStrong hands-on experience with TypeScript and Node.jsExperience building API-first microservice architecturesPractical experience integrating AI services, LLM APIs, or AI-assisted workflowsHands-on experience with AWS serverless technologies including Lambda, API Gateway, DynamoDB, and EventBridgeUnderstanding of RESTful and GraphQL APIsKnowledge of prompt engineering concepts and AI integration approachesUnderstanding of multi-tenant architectures and logical data isolation principlesInterest in AdTech products, automation, and AI-driven optimizationUpper-Intermediate or higher English level Will be a plus Experience with ML and AI experimentation projectsExposure to recommendation systems or data intelligence platformsExperience working with vector databasesFamiliarity with Infrastructure as Code tools such as Terraform or CloudFormationUnderstanding of observability and monitoring practices in distributed systemsExperience working with scalable cloud-native architectures Additional Information Personal Profile Strong analytical and problem-solving skillsProactive and ownership-driven mindsetPassion for modern Back-end engineering and AI technologiesAbility to collaborate effectively within distributed international teamsInterest in innovation, experimentation, and continuous learningStrong communication skills and attention to engineering quality