Senior Full Stack Developer in SIEMA TECH

SIEMA TECH is an international IT company that provides services in the field of software development and consulting. We work with clients from all over the world and use the most modern technologies to ensure the high quality of our work.

About the Role

We’re looking for a Senior Full Stack Developer to join our engineering team and help shape the future of programmatic advertising. You’ll architect and build high-performance systems that process millions of ad transactions in real-time, while leveraging cutting-edge AI technologies to optimize outcomes for our partners.

This is an opportunity to work at the intersection of ad-tech and AI, building systems that operate at massive scale with sub-millisecond latency requirements. You’ll own the full development lifecycle, with freedom to plan and execute — from architecture to deployment and working with modern technologies and a collaborative, high-performing team.

What You’ll Do:

• Design, develop, and maintain scalable full-stack applications using React, Node.js, and Python;
• Develop the core product offering implemented to track and analyse billions of events on websites and apps;
• Develop integrations with Supply-Side Platforms (SSPs) and Demand-Side Platforms (DSPs);
• Integrate AI/ML capabilities into our platform, including LLM APIs and on-premise model deployments;
• Build agentic workflows and AI-powered automation to enhance platform capabilities;
• Collaborate with product, data science, and engineering teams to deliver end-to-end solutions.

Requirements:

• 5+ years of professional software development experience;
• Strong proficiency in JavaScript/TypeScript, React, and Node.js;
• Solid experience with Python for backend development and data processing;
• Experience building high-performance, low-latency distributed systems;
• Strong understanding of RESTful APIs, microservices architecture, and cloud platforms (AWS/GCP);
• Experience with databases (SQL and NoSQL) and data streaming technologies;
• Excellent problem-solving skills and ability to work autonomously;
• Strong communication skills and collaborative mindset;
• English level: upper intermediate and above.

Preferred Qualifications:

Ad-Tech Experience (Strong Advantage):

• Experience with programmatic advertising ecosystems and OpenRTB protocols;
• Hands-on experience with SSP/DSP platforms (e.g., Xandr, Magnite, PubMatic, Index Exchange);
• Familiarity with Prebid.js, Prebid Server, and header bidding implementations;
• Understanding of auction mechanics, bid optimization, and ad serving infrastructure.

AI-Native Experience (Strong Plus):

• Experience building applications powered by LLMs (OpenAI, Anthropic, open-source models);
• Hands-on experience with agentic workflows and AI agent frameworks (LangChain, LangGraph,n8n, or similar);
• Experience deploying and serving ML models on-premise or via cloud APIs;
• Understanding of prompt engineering, RAG architectures, and tool-use patterns;
• Familiarity with vector databases and embedding-based search.

What We Offer:

• Competitive salary;
• Flexible work environment — fully remote and global team;
• Opportunity to work with cutting-edge AI and ad-tech technologies;
• Collaborative team culture focused on learning and growth;
• Professional development budget and learning opportunities;
• Assistance (in the absence) in the registration of the IE (legal and accounting support);
• Training and continuous development: internal trainings, certification programs, communities of interest, English language courses;
• Fully official salary (payment to the IE’s current account).

The interview consists of 2 stages: introductory interview, technical interview/interview with the client.

If you are interested in this vacancy and meet the requirements, send your resume and motivation letter to our email. We look forward to welcoming you to our team!