
Aivars Kalvāns is a FinTech developer, software architect, and consultant. He spent more than 18 years developing and architecting payment card software for acquiring and issuing, accounting and utility payments through mobile phones, ATMs, and POS terminals. At the moment he is a contractor for Ebury exploring the Foreign Exchange area of the FinTech landscape.
- QuerySet.explain(): make it make sense

Amanda is an Engineering Manager at Vinta Software. She considers herself to be a hybrid professional, having a background in business and software engineering. Amanda enjoys getting into technical topics, having been a speaker at conferences such as DjangoCon US, DjangoCon Europe and Python Brasil in the past, but loves discussing the overlap and challenges around technical and non-technical domains. She’s a social introvert with a passion for cooking, writing, music, video games and (shockingly, based on her history) strength training. Her current goal is to be less chronically online and touch some grass from time to time.
- What if you became an open source contributor in 2025?

Christian Heitzmann, MSc ETH CSE, is the founder and owner of SimplexaCode AG, based in Lucerne, Switzerland. He is a certified software developer in Java and Python, holding teaching diplomas in both Computer Science and Mathematics, as well as a CAS in Machine Learning. With over 20 years of experience in software development and 12 years of teaching Java, Python, mathematics, and algorithms, Christian is also a regular contributor to IT journals, sharing his expertise in the field.
- What We Can Learn from Exemplary Python Documentation

Daniel is a software engineer with a background in first, local, and then international and VC-backed startups. He's now the lead engineer at Reckon Digital, where he directs and coordinates several projects with clients such as the UN's World Food Programme.
- Inside the Black Box: The Anatomy of Virtual Environments

Hi, I'm Daniel, a software engineer based in Barcelona with a knack for Data Science and Machine Learning.
I've worked in startups and scale-ups in Brazil, Germany, and the US, mostly building software with Python and Java.
I'm an open-source enthusiast and I've contributed to projects such as dask, xarray, geopandas, ibis, and datafusion-python bindings.
- Unifying Data Management in Python with Ibis

I'm a technologist, born and raised in sunny Lisbon, now based in Copenhagen. My work lies in the intersection of Machine Learning & AI, Data, Software, and People. I'm in love with Technology, and how it can improve people's lives.
In the past, I've worked in Consumer Electronics, Public Institutions, Big Three Management Consulting, and YC-backed startups. The common thread? Solving hard problems end-to-end.
- RAG: Tricks from the trenches.

- Tools to setup great Python projects: 2025 update

Hacker, tabletop gamer, karate practitioner, musician and amateur cook.
Also I’m a software developer in my spare time, in python whenever possible.
- Simulation of life and of a society

Emma is actively involved in open source communities. She serves on the DISC Steering Committee of NumFOCUS. She's also a member of the PgUS Software Foundation, and the founder and organizer of the PG Armenia community group in Yerevan. She is a Developer Advocate, and she enjoys contributing to developer communities by mentoring, giving talks, and organizing meetups.
- Property-based testing the Python way

Gertrude is a solutions engineer at Paystack, specializing in cloud computing, software development, and cybersecurity. She is a mentor with Na’amal and volunteers with PyLadies Ghana. She supports underrepresented groups and fosters inclusive tech communities. She contributes to Everything Open Source and speaks at tech events on cloud security and her tech transition journey. She is passionate about empowering others and advocates for a thriving global tech ecosystem.
- Building a Thriving Tech Ecosystem: The Role of PyLadies in Fostering Growth and Inclusion

Giunio is a freelance software engineer working for research labs, gouvernmental institutions and startups across Europe.
He recently published the FastAPI Cookbook Packt edition.
He holds an Industrial Engineering degree from the University of Basilicata, Italy, and a PhD in numerical simulations from Paris-Saclay University, France.
He loves supporting education by sharing his knowledge in masterclasses and lectures in schools and universities.
- FastAPI Meets Langchain: crafting a RAG AI-powered chatbot

I am a Data Scientist and a Researcher. As a programmer, I program with Python and PHP. More info - https://x.com/hamplustech | https://GitHub.com/hamplustech | https://LinkedIn.com/in/hamplustech
- Real-time visualization using dash and plotly

Lilinoe Harbottle is an Indigenous Data Scientist who bridges data algorithms, robotics, and healthcare. She leads AI initiatives at a San Francisco startup, developing models for autonomous systems and natural language processing. At Auris Health (Johnson & Johnson), she enhanced medical robotic systems, improving bronchoscopy and urology procedures. A champion for open source and inclusive tech communities, she is a Sequoyah Fellow of the American Indian Science & Engineering Society (AISES).
- Python-Driven Robotics: Where Bytes Meet Biopsies
Back-End Software Engineer at CheckSec.
From Porto, Portugal.
More than 5 years of experience with Python and Django.
Focused in porting SPAs and developing Django applications using the hypermedia approach with HTMX and Alpine.js.
Helped build products in several markets such as education and real estate, including CMS platforms, GIS integration, and event management.
Multiple freelance projects deployed using these technologies.
- Django & HTMX: Patterns for Success

Senior software developer and architect with 12+ years of experience leading international teams, launching startups, speaking at technology conferences, writing and reviewing hundreds of thousands of lines of code, and сontributing to the open-source community as an award-winning code mentor.
- Building pure Django REST API

I have been working in tech for over 35 years, and now spend my time exploring emerging developer technologies to help developers understand how they work and how they can adopt them. I am passionate about open source, and how open source enables developers to innovate.
- Build without limits - lessons learned from using generative AI dev tools

Rodrigo Girão Serrão is the author of multiple independently published books on Python, programming, and mathematics, and frequently blogs about those same topics.
Rodrigo has also presented talks and tutorials at some of the largest Python conferences in the world, including PyCon US, EuroPython, and multiple European PyCons.
By creating technical content that is easily digestible by those looking to improve their Python knowledge, Rodrigo is working to help everyone appreciate the elegance of the Python language and to make an effective use of the tools it provides.
When he is not working or writing, Rodrigo can be found playing board games, walking his dog, or exercising at the gym.
- The Pokémon trainer's guide to Polars

Developer at a large learning platform at FCT|FCCN (https://www.fccn.pt/), with a special interest in web accessibility and search engine optimization. I have a Bachelors degree in Multimedia Technologies and Communication and a Master degree in Computer Engineering. I do regular contributions to open source and am always looking for ways to help communities grow.
- An A11y for better SEO

Stefanie Molin is a software engineer at Bloomberg in New York City, where she tackles tough problems in information security, particularly those revolving around data wrangling/visualization, building tools for gathering data, and knowledge sharing. She is also a core developer of numpydoc and the author of “Hands-On Data Analysis with Pandas: A Python data science handbook for data collection, wrangling, analysis, and visualization,” which is currently in its second edition and has been translated into Korean and Chinese. She holds a bachelor’s of science degree in operations research from Columbia University's Fu Foundation School of Engineering and Applied Science, as well as a master’s degree in computer science, with a specialization in machine learning, from Georgia Tech. In her free time, she enjoys traveling the world, inventing new recipes, and learning new languages spoken among both people and computers.
- (Pre-)Commit to Better Code