Theodoros Psallidas

Building frontier agentic platforms with LangGraph.

Senior Software Engineer at ProxyFoods. PhD candidate in Computer Science, University of Thessaly.

Experience

Keys 1 to 6 jump to a role.Tap a role to collapse it.

ProxyFoodsRemote · Greece · Feb 2025 – present

  1. Formulation engine for nutrition, cost, sensory profiling, and mass-balance validation.
  2. Agentic recipe generation with LangGraph, RAG, and human-in-the-loop ingredient matching.
  3. Cross-service authorization with OpenFGA and shared auth, tracing, logging, and exception libraries.
  • note: Formulation engine — core domain model
  • note: LangGraph — agent orchestration
  • note: human-in-the-loop — a person approves ingredient matches
  • note: OpenFGA — authorization shared across services
  • stack: React 19, TypeScript, FastAPI, Python, LangGraph, OpenAI, Langfuse, OpenFGA, SQLAlchemy, Azure SQL, Docker, Azure, OpenTelemetry

MyTripMyWayGreece · Jun 2025 – Mar 2026

  1. Persona-based recommendations with six interpretable travel personas and itinerary feasibility modeling.
  2. Full-stack POI aggregation, booking and payment flows, and interactive map-based itineraries.
  • note: six interpretable travel personas — basis of the recommendations
  • note: itinerary feasibility modeling — checks a plan can actually be travelled
  • note: booking and payment flows — Stripe
  • stack: Next.js, React, MobX, Tailwind CSS, Leaflet, FastAPI, SQLAlchemy, MariaDB, Docker, Google Maps, Stripe

Behavioral SignalsRemote · Greece · Mar 2024 – Feb 2025

  1. Delivered agent matching, analytics, monitoring, and scalability improvements for real-time routing.
  2. Designed, built, and owned the audio deepfake detection application end-to-end.
  • note: agent matching — real-time routing
  • note: audio deepfake detection — designed, built and owned end-to-end
  • stack: ReactJS, FastAPI, Django, Docker, Ansible, Azure, AWS, PostgreSQL, Milvus, MLflow

NCSR DemokritosRemote · Greece · Dec 2022 – Feb 2024

  1. Built music copyright monitoring and inference pipelines for IoT and Raspberry Pi fleets.
  2. Migrated models to deep learning and FAISS vector search to improve detection latency and accuracy.
  • note: music copyright monitoring — Museek project
  • note: FAISS vector search — lower detection latency
  • stack: ReactJS, FastAPI, PyTorch, FAISS, PostgreSQL, Docker, Balena, AWS, MLflow

OptechainOn-site · Argyroupoli, Greece · Oct 2020 – Feb 2024

  1. Led frontend and backend development for digital signage and EV-charging stations.
  2. Ran the Azure and Docker stack and managed device-fleet updates for safer rollouts.
  • note: digital signage and EV-charging stations — led frontend and backend
  • note: device-fleet updates — safer rollouts
  • stack: React, Angular, Node.js, C#, Azure, Docker, MSSQL, Balena, Mender

NCSR DemokritosRemote · Greece · Dec 2019 – Jul 2022

  1. Built video summarization and multimodal analysis models for the Enorasi project.
  2. Improved summarization through model architecture and feature-fusion experiments.
  3. Extended benchmark labeling to reduce evaluation variance.
  • note: video summarization — Enorasi project
  • note: feature-fusion experiments — architecture and fusion changes
  • note: benchmark labeling — less evaluation variance
  • stack: PyTorch, scikit-learn, Python, Computer Vision, Multimodal ML

Publications

  1. 2024A multimodal dataset for electric guitar playing technique recognitionA. Mitsou et al. · Data in Brief
  2. 2023Video summarization based on feature fusion and data augmentationT. Psallidas, E. Spyrou · Computers
  3. 2022Summarization of user-generated videos fusing handcrafted and deep audiovisual featuresT. Psallidas, E. Spyrou, S. J. Perantonis · SMAP
  4. 2022ENORASI assistive computer vision-based system for the visually impaired: a user evaluation studyA. Mitsou et al. · PETRA
  5. 2022Multimodal video summarization based on fuzzy similarity featuresT. Psallidas, M. D. Vasilakakis, E. Spyrou, D. K. Iakovidis · IEEE IVMSP
  6. 2021Multimodal summarization of user-generated videosT. Psallidas et al. · Applied Sciences
  7. 2020ARCHEO: a dataset for sound event detection in areas of touristic interestT. Psallidas et al. · SMAP
  8. 2020Dimensionality reduction and attention mechanisms for extracting affective state from sound spectrogramsG. Pikramenos et al. · ICPRAM

Full list on Google Scholar.

Education

  • PhD Candidate in Computer ScienceUniversity of Thessaly · 2021 – present
  • MSc in Data ScienceUniversity of Peloponnese · 2019 – 2021Thesis: Multimodal summarization of user-generated videos from wearable cameras
  • BSc in Computer ScienceUniversity of Thessaly · 2013 – 2018

Certifications

Open source

More on GitHub.