Lazaros Toumanidis

Software engineer working on multi-agent AI and ML systems. Co-founder of Waldiez.

waldiez.io Google Scholar LinkedIn GitHub GitLab CV (PDF)

About

Software engineer with over ten years of experience building research and production software, mostly within EU-funded R&D projects: mobile and wearable applications, backend services and APIs, and the deployment and optimisation of machine-learning models.

Since late 2024 I have been working full-time on Waldiez, a company I co-founded, building open-source tools for designing and running multi-agent AI systems. Previously a research associate at the CoNSeRT laboratory, University of West Attica (2016–2024); project-based developer at ThinGenious since 2020. 24 peer-reviewed publications.

Projects

Waldiez Open-source tool for visually designing, exporting and running AG2 multi-agent workflows, with JupyterLab and VS Code extensions. github.com/waldiez/waldiez wactorz Actor-model runtime for coordinating AI agents in IoT settings over MQTT. Basis of the dAIEDGE SYNAPSE open-call project (2026). github.com/waldiez/wactorz

Publications

Full list on Google Scholar → BibTeX ↓
  1. P. Kasnesis, C. Chatzigeorgiou, L. Toumanidis, and A. Contiero Syropoulou, "Not Every Call Needs a Frontier Model: Per-Call-Site Evaluation of Small Language Models in a Deployed Agentic Home-Automation System," SLM-Agents: 1st NeurIPS Workshop on SLMs for Agentic Systems, to appear, 2026. arXiv:2610.09021
  2. P. Kasnesis, L. Toumanidis, C. Chatzigeorgiou, A. Contiero Syropoulou, and M. De Prado, "One Agent per Zone: Decentralised Active Inference under Partial Observability for Multi-Zone HVAC Control on Edge Hardware," arXiv preprint, 2026. arXiv:2610.19790
  3. P. Kasnesis, L. Toumanidis, D. Jahier Pagliari, and A. Burrello, "Replacing Attention With Modality-Wise Convolution for Energy-Efficient PPG-Based Heart Rate Estimation Using Knowledge Distillation," IEEE Journal of Biomedical and Health Informatics, vol. 30, no. 1, pp. 339–352, 2026. 10.1109/JBHI.2025.3580474
  4. P. Kasnesis, T. Plavoukou, A. Contiero Syropoulou, L. Toumanidis, and G. Georgoudis, "A Knee Rehabilitation Exercises Dataset for Postural Assessment Using Wearable Devices," Scientific Data, 2025. 10.1038/s41597-025-04963-4
  5. A. Antikatzidis, M. Feidakis, K. Marathaki, L. Toumanidis, G. Nikolaou, and C. Z. Patrikakis, "Enrich Humanoids With Large Language Models (LLM)," 2024 IEEE Global Engineering Education Conference (EDUCON), 2024. 10.1109/EDUCON60312.2024.10578585
  6. P. Kasnesis, L. Toumanidis, A. Burrello, C. Chatzigeorgiou, and C. Z. Patrikakis, "Feature-Level Cross-Attentional PPG and Motion Signal Fusion for Heart Rate Estimation," 2023 IEEE 47th Annual Computers, Software, and Applications Conference (COMPSAC), 2023. 10.1109/compsac57700.2023.00267
  7. J. Choi, L. Toumanidis, C. M. Yeum, C. Patrikakis, A. Lenjani, X. Liu, P. Kasnesis, R. Ortiz, N.-J. Jiang, and S. J. Dyke, "Automated Graffiti Detection: A Novel Approach to Maintaining Historical Architecture in Communities," Applied Sciences, vol. 12, no. 6, 2022. 10.3390/app12062983
  8. P. Monachelis, P. Kasnesis, L. Toumanidis, C. Z. Patrikakis, and P. Papadopoulos, "Evaluation and Visualization of Trustworthiness in Social Media – EUNOMIA's Approach," 2022 IEEE 46th Annual Computers, Software, and Applications Conference (COMPSAC), 2022. 10.1109/compsac54236.2022.00038
  9. P. Monachelis, L. Toumanidis, P. Kasnesis, and C. Patrikakis, "Combating Fake News in Social Networks Through the Active Participation of Users: The Approach of EUNOMIA Project," International Journal of Electronic Governance, vol. 14, 2022. 10.1504/ijeg.2022.123246
  10. L. Toumanidis, P. Kasnesis, C. Chatzigeorgiou, M. Feidakis, and C. Patrikakis, "ActiveCrowds: A Human-in-the-Loop Machine Learning Framework," Frontiers in Artificial Intelligence and Applications, vol. 338, pp. 176–184, 2021. 10.3233/faia210090
  11. P. Kasnesis, L. Toumanidis, and C. Z. Patrikakis, "Combating Fake News with Transformers: A Comparative Analysis of Stance Detection and Subjectivity Analysis," Information, vol. 12, no. 10, 2021. 10.3390/info12100409
  12. P. Kasnesis, R. Heartfield, X. Liang, L. Toumanidis, G. Sakellari, C. Patrikakis, and G. Loukas, "Transformer-Based Identification of Stochastic Information Cascades in Social Networks Using Text and Image Similarity," Applied Soft Computing, vol. 108, 2021. 10.1016/j.asoc.2021.107413
  13. P. Kasnesis, R. Heartfield, L. Toumanidis, X. Liang, G. Loukas, and C. Patrikakis, "A Prototype Deep Learning Paraphrase Identification Service for Discovering Information Cascades in Social Networks," 2020 IEEE International Conference on Multimedia & Expo Workshops (ICMEW), 2020. 10.1109/ICMEW46912.2020.9106044
  14. L. Toumanidis, R. Heartfield, P. Kasnesis, G. Loukas, and C. Patrikakis, "A Prototype Framework for Assessing Information Provenance in Decentralised Social Media: The EUNOMIA Concept," E-Democracy – Safeguarding Democracy and Human Rights in the Digital Age, vol. 1111, 2019. 10.1007/978-3-030-37545-4_13
  15. C. Chatzigeorgiou, P. Kasnesis, and L. G. Toumanidis, "Exploiting Edge Computing for Privacy Aware Tourism Demand Forecasting," IT Professional, vol. 21, no. 3, 2019. 10.1109/MITP.2019.2901876
  16. P. Kasnesis, C. Chatzigeorgiou, L. Toumanidis, and C. Z. Patrikakis, "Gesture-Based Incident Reporting Through Smart Watches," 2019 IEEE International Conference on Pervasive Computing and Communications Workshops (PerCom Workshops), 2019. 10.1109/PERCOMW.2019.8730586
  17. P. Kasnesis, D. G. Kogias, L. Toumanidis, M. G. Xevgenis, C. Z. Patrikakis, G. Giunta, and G. L. Calsi, "An IoE Architecture for the Preservation of Cultural Heritage: The STORM Use Case," Harnessing the Internet of Everything (IoE), 2019. 10.4018/978-1-5225-7332-6.ch009
  18. L. Toumanidis, E. Bocaj, P. Kasnesis, and C. Z. Patrikakis, "Supporting Cultural Heritage Preservation Through Game-Based Crowdsourcing," Strategic Innovative Marketing and Tourism, 2019. 10.1007/978-3-030-12453-3_114
  19. L. Toumanidis, K. Karapetros, C. Giannousis, D. G. Kogias, M. Feidakis, and C. Z. Patrikakis, "Developing the Museum-Monumental Experience from Linear to Interactive Using Chatbots," Strategic Innovative Marketing and Tourism, 2019. 10.1007/978-3-030-12453-3_133
  20. C. Chatzigeorgiou, L. Toumanidis, D. Kogias, C. Patrikakis, and E. Jacksch, "A Communication Gateway Architecture for Ensuring Privacy and Confidentiality in Incident Reporting," 2017 IEEE 15th International Conference on Software Engineering Research, Management and Applications (SERA), 2017. 10.1109/SERA.2017.7965759
  21. P. Kasnesis, C. Z. Patrikakis, D. Kogias, L. Toumanidis, and I. S. Venieris, "Cognitive Friendship and Goal Management for the Social IoT," Computers & Electrical Engineering, vol. 58, 2017. 10.1016/j.compeleceng.2016.09.024
  22. E. Katsadouros, D. Kogias, L. Toumanidis, C. Chatzigeorgiou, and C. Z. Patrikakis, "Teaching Network Security Through a Scavenger Hunt Game," 2017 IEEE Global Engineering Education Conference (EDUCON), 2017. 10.1109/EDUCON.2017.7943094
  23. P. Kasnesis, L. Toumanidis, D. Kogias, C. Z. Patrikakis, and I. S. Venieris, "ASSIST: An Agent-Based SIoT Simulator," 2016 IEEE 3rd World Forum on Internet of Things (WF-IoT), 2016. 10.1109/wf-iot.2016.7845409
  24. M. G. Xevgenis, L. Toumanidis, D. G. Kogias, and C. Z. Patrikakis, "The Virtual Lab (VLAB) Cloud Solution," 2016 IEEE Globecom Workshops (GC Wkshps), 2016. 10.1109/GLOCOMW.2016.7849065
  25. C. Z. Patrikakis, S. A. Kalantzis, L. Toumanidis, and F. Zisimos, "Supporting Lab Courses Using OpenStack," E-Democracy 2013, vol. 441, 2014. 10.1007/978-3-319-11710-2_9

Connect

laztoum@protonmail.com CV (PDF)