Sergio Jimenez Jimenez

AI Product Owner · Senior Engineer. Owning GenAI products end to end, from business use case to production and adoption.
+41 76 736 27 59 | sergiojj932@gmail.com | Basel, Switzerland | seryux.ip-ddns.com | www.linkedin.com/in/sergio-j-jimenez | github.com/seryusjj

PROFESSIONAL SUMMARY

Senior engineer with around ten years building production systems for regulated industries, and founder of Liftory, an AI product I owned end to end from idea to the App Store and more than 100 active users, with an agentic GenAI core (RAG and tools over MCP on the Microsoft Agent Framework). At Pdftools I own the AI enablement platform used across product lines, taking models from evaluation to fast, reliable production inference (ONNX Runtime, FastAPI), and I help the product owner with the decisions behind what we build. The engineering background keeps roadmaps and feasibility grounded in how the systems work. Comfortable scoping needs into use cases, working across cross-functional teams, and collaborating with non-technical stakeholders. MSc in Artificial Intelligence, SAFe Agilist, and Scrum Master.

WORK EXPERIENCE

Senior Software Engineer, AI Enablement
Pdftools (Smallpdf) | Zurich · remote Basel
August 2025 - Present
  • Own the AI enablement platform that every Pdftools product line builds on: ONNX Runtime model serving, FastAPI inference services, and NLP pipelines on Hugging Face Transformers and spaCy.
  • Take models from evaluation to production: reimplement inference pipelines to run efficiently (for example, porting GLiNER to ONNX Runtime and C#), with containerized Kubernetes deployment, CI/CD, observability, and regression evaluation in the release pipeline.
  • Work with the product owner and research stakeholders to shape the product and turn evaluated models into reliable, performant inference services that multiple product teams build on.
Senior Software Engineer
Pdftools (Smallpdf) | Zurich · remote Basel
October 2022 - Present
  • Core engineer (team of 4 within a 20+ engineer Swiss organization) on Smart Redact, the AI-based PII removal product for regulated industries (healthcare, finance, insurance, government, legal). Hybrid Named Entity Recognition plus deterministic rules across seven languages.
  • Also contributed to OCR Service (180+ languages). Both products run on AWS on a horizontally scalable manager / worker architecture I helped design.
  • Own infrastructure as code (Terraform), CI/CD (Azure DevOps and GitHub Actions), observability, and on-call practices across product lines.
  • Drove the team's SDLC standards (review norms, testing strategy, release automation, architecture decision records) and mentor engineers across teams.
Lead Engineer, Flight Operations Optimization (OPSD)
Swiss International Air Lines (Lufthansa Group) | Basel · Zurich
September 2021 - October 2022
  • Architected the Grand Solver, a real-time cost-evaluation system that operations crews across multiple Lufthansa Group airlines used to make live operational decisions, with non-technical users relying on it in production. Cloud-native on GCP, delivered in partnership with Google Cloud.
  • Promoted to lead on the Lufthansa Group-wide OPSD initiative. Shaped the long-term roadmap, built simulation and automation for cross-airline cost comparison, and ran cross-airline refinement sessions with business stakeholders.
  • Recognized internally as an outstanding high achiever for technical depth, stakeholder communication with non-engineering domain experts, and collaborative mindset.
Software Engineer
Swiss International Air Lines (Lufthansa Group) | Basel
July 2019 - September 2021
  • Full-stack cost-maintenance and budgeting application reconciling vendor invoices against contract terms. Stack: .NET Framework and .NET Core backend, Angular with RxJS frontend, PL/SQL on Oracle, Docker on GCP.
Senior Software Engineer · Software Engineer
Neueda | Málaga
April 2018 - June 2019
Later acquired by Version 1.
  • Senior C++ developer on an exchange platform running on Linux: CMake, Docker, Redis, RabbitMQ, Google Protocol Buffers, gtest and gmock. Profiled with Valgrind and perf. Services containerized on Amazon EKS, with CI on Jenkins and TeamCity.
Software Developer
Wilken Software Group | Gijón
October 2017 - April 2018
  • ERP for tourism clients (including SkiData): JEE8 on WildFly with an Ext JS frontend. Tooling: Maven, Arquillian, Jenkins.
Software Developer
Mecalux Warehouse Solutions | Gijón
August 2015 - October 2017
  • Warehouse management system modules built on .NET Web API, WPF, WinForms, and Entity Framework. Designed and built a 3D warehouse-simulation tool (XNA / MonoGame embedded in WPF) that lets users configure a layout, persist it to the database, and run virtual operations end-to-end.
  • BDD with SpecFlow, unit testing with NUnit and Moq, and a CruiseControl.NET, Nant, and WiX release pipeline.
Software Developer Intern · IT Intern
Sweetspot · University of Oviedo | Gijón · Oviedo
September 2013 - May 2015
  • Android and Android Wear application in Java for Sweetspot. The application won the company-hosted contest. Earlier, computer-systems maintenance at the University of Oviedo.

PROJECTS

Liftory
https://liftory.ch | An AI product I own end to end. Fitness tracking with an agentic GenAI chat worker. More than 100 registered users.
2025 - present
  • Founder and sole owner. Took the product from idea to Proof of Concept to a live app on the App Store and Google Play with more than 100 registered users, owning the roadmap, the release cadence, and adoption. Shipped an Ionic and Angular mobile app, native watchOS (Swift) and Wear OS (Kotlin and Jetpack Compose) companions with bidirectional phone-to-watch sync, a Next.js marketing site at liftory.ch, and a .NET 10 backend on PostgreSQL.
  • Built an agentic AI worker on the Microsoft Agent Framework (MAF) that designs personalized training plans through multi-turn conversations, calling domain tools over the Model Context Protocol (MCP) and grounding its answers with RAG over a curated fitness corpus. Orchestration is model-agnostic, with typed, schema-constrained tool calls. Applies the automated planning, reasoning, and NLP from my MSc in Artificial Intelligence.
  • Workers are stateless and horizontally scalable behind RabbitMQ. Full OpenTelemetry observability (Grafana, Loki, Tempo, Prometheus) and a private Gitea content pipeline publishing versioned brand-asset packages consumed by the web and mobile builds.

EDUCATION

Master of Science in Artificial Intelligence
Universidad Internacional de La Rioja (UNIR) | Online (Spain)
March 2024 - March 2026
Focus on Machine Learning, Deep Learning, Natural Language Processing, Automated Reasoning and Planning, and Computer Vision.
Master's Degree, Mobile Applications Development
Universitat Oberta de Catalunya (UOC) | Online (Spain)
September 2017 - February 2020
Bachelor's Degree, Computer Science (Software Development)
University of Oviedo | Spain
September 2011 - July 2015

SKILLS

Generative AI and applied ML: LLMs · prompt engineering · fine-tuning, RAG · semantic search, Agentic workflows (MAF · MCP), PyTorch · TensorFlow · ONNX Runtime, Hugging Face Transformers · spaCy, FastAPI inference services
Cloud and infrastructure: AWS (Lambda, S3, SQS, EKS), GCP (BigQuery, Dataflow), Terraform · Kubernetes · Docker
Data and backends: Event-driven architecture, Kafka · RabbitMQ, PostgreSQL · BigQuery · SQL / NoSQL, REST · gRPC
Programming languages: Python, C# / .NET (Framework, Core), TypeScript / Node, Java (JEE), C / C++
Frontend: React / Next.js, Angular with RxJS, Ionic
SDLC and quality: GitHub Actions · Azure DevOps · Jenkins, OpenTelemetry · Grafana · Loki · Tempo · Prometheus, Unit, BDD (SpecFlow), and integration testing

CERTIFICATIONS

LANGUAGES