Senior Software Engineer · AI Enablement

SergioJimenez Jimenez

Cloud-native data platforms, applied ML in production, and end-to-end product ownership.

Currently: Pdftools (Smallpdf)
Based in: Basel, Switzerland
Building: Liftory

01About

Senior engineer with around ten years building production systems, much of it for regulated industries. At Pdftools I own the AI enablement platform across product lines and have shipped on Smart Redact (AI-based PII removal for healthcare, finance, government, and legal) and OCR Service (horizontally scalable manager / worker architecture for 180+ languages). On the side, Liftory is my personal R&D platform: an agentic chat worker on the same scaling patterns, used to validate ideas before they reach the day job. Track record of setting SDLC standards, mentoring engineers, and translating research into reliable services.

02What I do

01
AI / ML in production
PyTorch · TensorFlow · ONNX + ONNX Runtime · Hugging Face Transformers · spaCy · FastAPI inference services · RAG and LLM orchestration
02
Cloud and infrastructure
AWS (Lambda, S3, SQS, EKS) · GCP (BigQuery, Dataflow) · Terraform · Kubernetes · Docker
03
Data and backends
Event-driven architecture · Kafka · RabbitMQ · PostgreSQL · BigQuery · SQL / NoSQL · REST · gRPC
04
Programming languages
Python · C# / .NET (Framework, Core) · TypeScript / Node · Java (JEE) · C / C++
05
Frontend
React / Next.js · Angular with RxJS · Ionic
06
SDLC and quality
GitHub Actions · Azure DevOps · Jenkins · OpenTelemetry · Grafana · Loki · Tempo · Prometheus · Unit, BDD (SpecFlow), and integration testing

03Selected work

Liftory

2025 → present

Personal R&D platform. Fitness tracking with an agentic AI chat worker. 100+ registered users.

Founder and sole engineer. Shipped end-to-end: an Ionic and Angular mobile app on the App Store and Google Play, 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 chat worker (skill-driven, multi-turn) that designs personalized training plans. RAG over a curated training and nutrition corpus using a local ONNX bge-m3 embedding model and hybrid BM25 plus cosine retrieval, orchestrated via OpenAI's gpt-5-mini with constrained decoding for typed tool calls. Chose RAG over fine-tuning: the corpus updates frequently and is too small for fine-tuning to add value.

liftory.ch

Selected experience

Pdftools (Smallpdf)
Senior Software Engineer, AI Enablement
Aug 2025 - present
Pdftools (Smallpdf)
Senior Software Engineer
Oct 2022 - present
Swiss International Air Lines (Lufthansa Group)
Lead Engineer, Flight Operations Optimization (OPSD)
Sep 2021 - Oct 2022
Swiss International Air Lines (Lufthansa Group)
Software Engineer
Jul 2019 - Sep 2021
Neueda
Senior Software Engineer · Software Engineer
Apr 2018 - Jun 2019
Wilken Software Group
Software Developer
Oct 2017 - Apr 2018

Full work history and education

04Open source and experiments

Procedural graphics

Procedural Planet

A real-time procedural planet generator. Layered noise shapes the terrain, a custom shader colours it by elevation, and gradient controls reshape an entire world as you adjust them.

Godot 3.2C#ShadersNoise

View on GitHub

Emulator

CHIP-8 Emulator

A CHIP-8 virtual machine written from scratch in Flutter. A steady clock drives the fetch, decode and execute loop, so the classic 8-bit ROMs run natively on Android and iOS.

FlutterDartEmulation

View on GitHub

Mobile, award-winning

Sweetspot

An Android and Android Wear app in Java, with user authentication and phone-to-watch synchronisation. It won the company's internal contest.

AndroidJavaAndroid Wear

View on GitHub

</> game dev

Teaching, free course

How to make games

A free, start-to-finish course I wrote on building cross-platform games with Cocos2d-x. Twelve chapters take you from an empty project all the way to shipping on Android.