Senior AI / Machine Learning Engineer (LLMs & Python Backend)

**Company: XOSOFT Technologies Private Limited** **Location: Lahore, Pakistan (On Site)** **Job Type: Full\-time** We are seeking a  **Senior AI / Machine Learning Engineer**  with strong  **Python backend expertise**  to design, build, and operate intelligent systems using  **LLMs, traditional ML models, and scalable backend services** . This role requires hands\-on experience across the  **full AI lifecycle** from data preparation and model training to deployment, monitoring, and continuous improvement while collaborating closely with backend systems and APIs. **Key Responsibilities** **Artificial Intelligence \& Machine Learning** * Design, train, evaluate, and deploy  **machine learning models**  for real\-world use cases. * Fine\-tune and integrate  **Large Language Models (LLMs)**  for conversational AI, extraction, classification, and decision support. * Determine when to use: * LLMs * Traditional ML models * Rule\-based or hybrid approaches * Build  **custom ML pipelines**  including data ingestion, feature engineering, training, validation, and inference. * Monitor model performance, drift, and accuracy over time. **LLM \& Generative AI Systems** * Integrate LLMs into applications for: * Chatbots and assistants * Natural language understanding * Structured data extraction * Content generation * Implement prompt engineering, output validation, and fallback strategies. * Reduce hallucinations through guardrails, validation logic, and hybrid designs. * Optimize latency, cost, and reliability of LLM\-powered systems. **Data \& Model Training** * Work with structured and unstructured datasets. * Prepare training datasets and labeling strategies. * Fine\-tune models using domain\-specific data when required. * Evaluate models using business\-oriented metrics, not just technical accuracy. * Document model behavior, assumptions, and limitations. **Python Backend Development** * Build and maintain  **Python\-based backend services**  and APIs. * Develop scalable, production\-grade services using frameworks such as FastAPI or similar. * Integrate AI models into backend workflows. * Ensure robust error handling, logging, and observability. * Optimize performance and concurrency (async programming, background tasks). **Required Qualifications** **Core Skills** * **4\+ years**  of professional experience in software engineering and/or machine learning. * Strong proficiency in  **Python** . * Hands\-on experience with  **machine learning model development** . * Experience integrating  **LLMs or NLP systems**  into applications. * Solid understanding of data structures, algorithms, and system design. * Experience deploying models and services into production environments. **AI / ML Expertise** * Supervised and unsupervised learning * NLP and/or conversational AI * Model evaluation and monitoring * Feature engineering and data preprocessing * Model fine\-tuning and experimentation **Backend \& Infrastructure** * REST APIs and backend service development * Async and concurrent programming concepts * Databases (SQL) * Caching systems (Redis or similar) * Cloud or container\-based deployments (nice to have) **Nice\-to\-Have** * Experience with speech\-to\-text or voice systems * Experience with vector databases or semantic search * Familiarity with MLOps tools and workflows * Knowledge of open\-source LLM ecosystems * Experience in search, recommendation, or ranking systems