Martin Ratajczak-Senior LLM Research Scientist
Check rate
Experience
Senior LLM Research Scientist
BYO Inc.
- Research and develop models for chatbots, NLP and LLMs (e.g. Llama, Qwen, OpenAI)
- Enhance chatbots with RAG, in-context learning
- Supervised fine-tuning (PEFT, LoRA), Huggingface or Unsloth
- Advanced training methods: Test-time training, (transductive) active learning, reinforcement learning
- High-throughput serving with vLLM
- Apply embedding models (e.g. SentenceTransformers), similarity/vector search or vector DB or ranking (e.g. LlamaIndex, Faiss, LangChain)
- Generate and filter synthetic data, clustering
- Detect hallucinations
- Evaluate chatbot models (Rouge, BLEU, F1-Score, Recall, Precision)
- Visualization of experiments (matplotlib)
Senior AI Research Scientist
Rev.com
- Research and develop model architectures in speech recognition systems (ASR), large language models (LLM), natural language processing (NLP), speaker diarization, speaker recognition, text formatting, summarization and chatbots
- Train and fine-tune neural networks and probabilistic models: CTC, Transducer, HMM, Segmental CRF, Conformer, Transformer, CNNs, RNNs
- Train on multi-GPU nodes and large scale data sets
- Optimize models for accuracy, size (e.g. quantization, pruning), and speed
- Implement and optimize decoding algorithms
- Data preparation: trained tokenizer, forced alignment, data cleanup scripts
- Advise on road maps and quarter planning, write epics and tickets, supervise junior researcher and developer
- Develop open-source ASR model as core member of research team
- Publish first-author scientific publication at Interspeech 2025 on speech recognition and machine learning
Machine Learning Engineer
e-bot7 - AI for Customer Service
- Implemented and trained chatbots using neural networks and NLP methods
Machine Learning Engineer
iTranslate
- Implemented and trained speech recognition system (ASR) for mobile phones
- Trained neural networks on multi-GPU system
Research Project Assistant
Technische Universität Graz
- Researched neural networks and probabilistic models for sequences
- Conducted machine learning (ML), speech recognition (ASR), and language model (LM) research
- Innovated, implemented, trained and published papers on recurrent neural networks (RNNs), conditional random fields (CRFs), sum-product networks, new regularization methods and losses, calculation and coding of gradients for custom models, and segmental CRFs
- Supervised master student project on machine learning and ASR
- Analyzed Ca imaging recordings of neuronal activity of anesthetized and awake mice
- Classified and visualized trajectories of brain states using dimension reduction (PCA, LDA), support vector machines (SVM), Kalman filter/smoother, clustering, regression, and time series forecasting
Research Project Assistant
RWTH Aachen University
- Implemented and trained an end-to-end machine translation system based on conditional random fields (CRFs) from scratch including gradients and losses for a distributed multi-node CPU grid
- Trained phrase-based statistical machine translation systems including language models (LM)
- Trained and implemented log-linear models for text classification, part-of-speech tagging, named entity identification and syntactic parsing
- Taught seminar and exercise courses in machine learning and pattern recognition including neural networks, statistical machine translation, and speech recognition (ASR)
Software Engineer
GAF AG
- Implemented software for geo-information systems, back-end server applications and web map services
Graduate Research Assistant
Ludwig-Maximilians-Universität München
- Analyzed and implemented online learning rules in neural networks
Software Engineer Internship
Max Planck Institute for Physics
- Implemented application to visualize learning processes (variants of Hebbian learning rule) and self-organization in neural networks (Hopfield network, associative memory, vector quantization, clustering, Boltzmann machine) for teaching
- Implemented scripts using Fortran, Perl and C++ to visualize Large Hadron Collider experiments from CERN
Software Engineer Internship
Siemens
- Implemented a network of biologically-inspired spiking neurons
Industry experience
See where this freelancer has spent most of their professional time.
Experienced in Information Technology, Education, and Aerospace and Defense.
Business area experience
See which departments and functions this freelancer has contributed to most.
Experienced in Research and Development, Product Development, Information Technology, and Customer Service.
Summary
- 17 years experience in machine learning (ML), 7.5 years of it in tech companies
- Specialized in neural networks and probabilistic models for sequences: Speech recognition (ASR), natural language processing (NLP), large language models (LLM) and generative AI, time series forecasting, classical machine learning and statistics, regression, classification, clustering, sequence-to-sequence models, supervised/unsupervised learning, anomaly detection, fraud detection
- Solve hard algorithmic problems, develop new architectures, build prototypes
- Train and fine-tuning models, optimize for accuracy, speed and size
- Integrate and deploy to cloud or on-prem (CPU, GPU, on-device, embedded)
- Develop in Python (15y), PyTorch (6.5y), Tensorflow (4y), Java, C++
- Research experience in machine learning at university labs and tech companies
- Let’s talk: Work as freelancer or company or employee
- Publish scientific papers, talk at conferences and present posters
Languages
Education
Technische Universität Graz
PhD studies (left lab) · Machine Learning · Graz, Austria
Queen's University Belfast
Erasmus student exchange · Physics and Computer Science · Belfast, United Kingdom
Ludwig-Maximilians Universität München (LMU)
Diploma in Physics (Master equivalent) · Physics · Munich, Germany
Certifications & licenses
Advanced Latin certificate
Märkisches Gymnasium
Statistics
Experience
Global experience
Expertise
Qualifications
Profile
Frequently asked questions
Have questions? Find more information here.
Martin is based in Munich, Germany and can operate in on-site, hybrid, and remote work models.
Martin speaks the following languages: German (Native), English (Advanced), Latin (Advanced), Polish (Advanced).
Martin has at least 18 years of experience. During this time, Martin has worked in at least 7 different roles and for 10 different companies. The average length of individual experience is 2 years and 10 months. Note that Martin may not have shared all experience and actually has more experience.
Based on recent experience, Martin would be well-suited for roles such as: Senior LLM Research Scientist, Senior AI Research Scientist, Machine Learning Engineer.
Martin's most recent position is Senior LLM Research Scientist at BYO Inc..
In recent years, Martin has worked for BYO Inc. and Rev.com.
Martin is most experienced in industries like Information Technology, Education, and Aerospace and Defense.
Martin is most experienced in business areas like Research and Development, Product Development, and Information Technology. Martin also has some experience in Customer Service.
Martin has recently worked in industries like Information Technology.
Martin has recently worked in business areas like Product Development and Research and Development.
Martin holds a Doctorate in Machine Learning from Technische Universität Graz and a Master in Physics from Ludwig-Maximilians Universität München (LMU).
Martin has 1 certificate: Advanced Latin certificate.
The availability of Martin needs to be confirmed.
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