Data Science Professionals (LLM & Core NLP)

About the Team
At Trendyol Tech, our mission is to create a positive impact in our ecosystem by enabling commerce through technology.
We solve complex problems with data, creativity, and agility — always driven by real outcomes. With a culture built on learning, collaboration, and ownership, we grow together while building what’s next.

About the Role
As a key member of our LLM & Core NLP team, you will spearhead the development of intelligent, data-driven solutions that power our platforms. This role involves much more than just model training; you will bridge the gap between cutting-edge academic research and tangible business impact, designing sophisticated architectures ranging from RAG (Retrieval-Augmented Generation) systems to autonomous agentic AI. You will act as a champion of our data culture, working closely with engineering and product stakeholders to translate complex free-text data into actionable strategies for search, recommendation, and content moderation. Leveraging your deep expertise in Python, PyTorch, and Large Language Models, you will tackle "impossible" questions and deliver optimized, high-performance AI solutions that define the future of our customer experience.

Responsibilites:
• Core NLP & LLM Development
• Design and implement state-of-the-art NLP architectures, focusing on Large Language Models (LLMs), Vision-Language Models (VLMs), and Agentic AI systems (MCP, A2A protocols, tool-calling).
• Construct and optimize deep learning models using advanced techniques such as Low-Rank Adaptation (LoRA/PEFT), quantization, distillation, and advanced prompting strategies (e.g., Chain-of-Thought, LLM-as-a-Judge).
• Develop and deploy Generative AI solutions for high-impact areas including search, recommendation engines, catalog management, user-generated content areas, and moderation.
• Build robust RAG (Retrieval-Augmented Generation) systems, handling the full pipeline from embedding generation and vector databases to context retrieval and answer synthesis.
• Data Strategy & Application
• Drive solutions from free-text data across multiple languages, utilizing extensive data mining and statistical analysis to extract actionable insights.
• Conduct exploratory data analysis (EDA)and rigorous error analysis to identify hidden patterns, navigate complex datasets, and establish ground truths.
• Innovate in data preprocessing, including the design of automated label generation workflows and data cleaning pipelines to ensure high-quality model input.
• Business Impact & Collaboration
• Partner with engineering and product stakeholders to identify opportunities where AI can solve critical business problems in mobile commerce and ad-tech.
• Synthesize complex technical methodology into clear business strategies, communicating findings effectively to management to drive decision-making.
• Champion a data-driven culture within the organization, advocating for best practices in machine learning and data science.
• Track and apply the latest developments in NLP and Gen AI literature to maintain a competitive edge in e-commerce business problems.

Expected Qualifications:
• Essential Background & Skills
• Education: Bachelor’s or Master’s degree in Computer Science, Engineering, Statistics, Mathematics, or a related field.
• Experience: 3+ years of hands-on experience in Data Science, with a specific focus on NLP, Generative AI, or LLM development
• Technical Proficiency: Strong command of Python and SQL. Extensive experience with deep learning frameworks (PyTorch, TensorFlow) and NLP libraries (Hugging Face Transformers, LangChain, Pandas, Scikit-learn).
• LLM Expertise: Proven track record in training, fine-tuning, and evaluating LLMs. Experience with OpenAI/Gemini APIs (chat/completions, embeddings, fine-tuning, tool-calling).
• Core NLP Knowledge: Deep understanding of foundational concepts including summarization, QA, information extraction, clustering, and semantic search.
• Communication: Excellent written and verbal communication skills in English, with the ability to explain complex AI concepts to non-technical teams.

• Preferred Qualifications (Nice-to-haves)
• Advanced Education: A PhD in AI, NLP, or Data Science.
• Domain Experience: Prior experience in mobile commerce, ad-tech, or self-service business models.
• Soft Skills: A "can-do" attitude with a curiosity for "impossible" questions, strong interpersonal skills, and a result-oriented mindset.

What We Offer
- Hybrid working model with flexibility: a schedule that helps you find the right balance between flexibility and team bonding, including work-from-abroad opportunities and a summer working model.
- Customisable FlexBenefits budget: Adjust your daily meal allowance, choose your health insurance package (and extend it to your spouse or children), and pick from additional benefits like fuel support or Trendyol shopping credits.
- Well-being support: Access to location-based in-house doctors, as well as psychologist and dietitian support, and HPV vaccination provision.
- Personalised training allowance and learning opportunities: Use your annual budget for any training or conference of your choice, explore our Learning Management System (LMS) anytime, and join in-person learning sessions offered throughout the year.
- Responsibility from day one: Take full ownership from the start in a culture where every voice is heard and valued.
- A diverse, international team: Collaborate with global peers across our offices in Berlin, Amsterdam, Dubai, and beyond, in a startup-spirited and collaborative environment.
- Opportunities to grow with the best: Tackle meaningful challenges, develop through hands-on experience, and grow with the support of expert guidance and global mentoring.
- Meaningful connections beyond tasks: Be part of team rituals, events, and social activities that help us stay connected and inspired.

Take the Next Step
If this role excites you, apply today, we look forward to taking the next step with you.
Want to get to know the team better first? Explore our Career Website, LinkedIn, or YouTube to learn more about #LifeatTrendyol and how we work.