Senior AI Engineer

Job Description

The Position

We are looking for an experienced AI Engineer to join the Discover Marketplace Platform team, driving the design, development, and optimization of our next-generation search experience — Search 2.0. This role will focus on leveraging Large Language Models (LLMs), vector search, and retrieval-augmented generation (RAG) to deliver semantic, context-aware, and high-relevance search across our global data marketplace.

What will you do?

• Collaborate with product managers, data engineers, backend/frontend developers, and stakeholders to translate business requirements into scalable AI-powered search capabilities.
• Design, build, and maintain the data ingestion pipeline, including entity recognition, taxonomy integration, and context enrichment using LLMs.
• Develop and optimize vector embedding generation, similarity search, and hybrid search integration (keyword + semantic).
• Implement retrieval-augmented generation (RAG) workflows, including query validation, entity recognition, context enrichment, and result summarization.
• Select, fine-tune, and integrate embedding models (e.g., BioBERT, Sentence Transformers, OpenAI Ada) to improve search accuracy for domain-specific datasets.
• Integrate with knowledge sources like eVOC and other terminologies for enriched metadata and improved retrieval.
• Build and maintain re-ranking algorithms combining keyword scores (OpenSearch) with vector similarity.
• Monitor system performance, optimize for latency, and implement caching strategies for high availability.
• Implement a feedback loop to continuously improve model accuracy based on user interactions.
• Ensure all AI pipelines meet security, compliance, and privacy standards, especially for sensitive health data.
• Participate in the full ML lifecycle — from experimentation, evaluation, and deployment to monitoring and retraining.

Qualifications, Skills & Experience Required

• Bachelor's or master's degree in computer science, Data Science, Machine Learning, or related field (or equivalent work experience)
• 5+ years of experience in applied machine learning or AI engineering, with at least 2 years working on search, NLP, or information retrieval systems
• Strong experience with LLMs, vector databases (e.g., Pinecone, Weaviate, Milvus, OpenSearch vector search), and semantic search
• Proficiency in Python and ML frameworks such as PyTorch or TensorFlow
• Hands-on experience with embedding models, transformers, and RAG architectures
• Familiarity with keyword search engines (OpenSearch/Elasticsearch) and hybrid search strategies
• Experience designing and operating data ingestion and enrichment pipelines
• Strong knowledge of NLP techniques (entity recognition, synonym handling, taxonomy integration)
• Experience with CI/CD for ML/AI models, model versioning, and deployment
• Understanding of cloud platforms (AWS preferred) and containerization (Docker, Kubernetes)
• Strong problem-solving skills and ability to work collaboratively in cross-functional teams

Nice to have

• Experience in biomedical or healthcare data search and retrieval
• Knowledge of eVOC or other domain-specific taxonomies
• Experience with multi-modal retrieval (text, images, structured data)
• Familiarity with conversational AI, chatbot integration, and user-facing NLP features
• Exposure to model monitoring tools and feedback loop systems

What we offer

• Exciting work in a great team, global projects, international environment
• Opportunity to learn and grow professionally within the company globally
• Hybrid working model, flexible role pattern (e.g., even 80% full-time is possible in justified cases)
• Pension and health insurance contributions
• Internal reward system plus referral programme
• 5 weeks annual leave, 5 sick days, 15 days of certified sick leave paid above statutory requirements annually, 40 paid hours annually for volunteering activities, 12 weeks of parental contribution
• Cafeteria for tax free benefits according to your choice (meal vouchers, Lítačka, sport, culture, health, travel, etc.), Multisport Card
• Vodafone, Raiffeisen Bank, Foodora, and discount programmes
• Up-to-date laptop and iPhone
• Parking in the garage, showers, refreshments, massage chairs, library, music corner
• Competitive salary, incentive pay, and many more

Ready to take up the challenge? Apply now

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Current Employees apply HERE

Current Contingent Workers apply HERE

Search Firm Representatives Please Read Carefully

Merck & Co., Inc., Rahway, NJ, USA, also known as Merck Sharp & Dohme LLC, Rahway, NJ, USA, does not accept unsolicited assistance from search firms for employment opportunities. All CVs / resumes submitted by search firms to any employee at our company without a valid written search agreement in place for this position will be deemed the sole property of our company. No fee will be paid in the event a candidate is hired by our company as a result of an agency referral where no pre-existing agreement is in place. Where agency agreements are in place, introductions are position specific. Please, no phone calls or emails.

Employee Status:

Regular

Relocation:

VISA Sponsorship:

Travel Requirements:

Flexible Work Arrangements:

Hybrid

Shift:

Valid Driving License:

Hazardous Material(s):

Required Skills:

Communication, Computer Science, Containerization, Conversational AI, Data Engineering, Data Science, Data Visualization, Design Applications, ElasticSearch, Engineering Software, Information Retrieval, Natural Language Processing (NLP), OpenAI, Professional Development, Search Strategies, Semantic Search, SEVIS, Social Collaboration, Software Configurations, Software Development, Software Development Life Cycle (SDLC), Solution Architecture, System Designs, Systems Integration, Testing

Preferred Skills:

Job Posting End Date:

09/1/2025

• A job posting is effective until 11:59:59PM on the day BEFORE the listed job posting end date. Please ensure you apply to a job posting no later than the day BEFORE the job posting end date.

Requisition ID:R362084