(Remote) Senior Software Engineer - Backend

Holisticon Insight (former Nexer Insight) is a division of focused on IoT, AI, and advanced analytics. We assist our customers in developing IoT services, portals, and mobile apps and, above all, analyze data using AI and advanced analytics to reduce costs, streamline, and find new opportunities for the business. We offer a B2B Contract : ~180 – 215 PLN net / hour + VAT We are looking for a hands-on Senior Software Engineer with experience in Python, AI and BigData to assist in design and implementation of our client's on-premise data platform with native AI agent capabilities. Your focus will be end-to-end implementation, designing components, and getting things done. This role is perfect for someone who enjoys working across backend engineering, AI integrations, and data-intensive systems. Design and develop backend components of the AI & Data Platform, including microservices, REST APIs, and system integrations. Implement AI / LLM features such as embeddings, RAG interfaces, vector search, and model inference workflows. Work with large-scale data systems (structured & unstructured), integrating with lakehouse, distributed storage, or streaming components. Deliver end-to-end solutions — from technical design to implementation and deployment. Collaborate with the Platform Architect and engineers across Data, ML, and Software teams to refine platform capabilities. 7–10+ years of experience as a Software Engineer (backend / data / distributed systems). ~ Strong proficiency in Python and experience writing production-grade, scalable code. ~ Hands-on experience with AI / LLM integrations : embeddings, inference, RAG, model APIs. ~ Experience with Big Data / distributed systems (e.G., Knowledge of at least one AI / ML framework (LangChain, Haystack, Hugging Face Transformers, etc.). ~ Strong communication skills in English. Nice to Have Experience with RAG architectures, agent orchestration frameworks, or AI agents. Familiarity with LangGraph, CrewAI, AutoGPT, ReAct-style agent architecture. Knowledge of additional languages (Go, Java, etc.). Fully remote job Private medical care Flexible working hours B2B or contract of employment Training budget (e.G. Microsoft Azure Certifications) Work equipment (laptop, 2 monitors, and accessories)