Diego is a Principal Software Engineer at Arm Ltd. This allowed him to organize the 2025 Core Developer Sprint at Arm in Cambridge, UK. It looks like this will be the biggest core sprint week to date.
Within Arm, he also runs the Python Guild, an internal community of over 1,400 members.
Also, Diego has been a EuroPython organizer since 2022.
Post-promotion mentoring
Diego regularly attends the Faster CPython weekly sync since October 2024 and has a standing sync with Brandt Bucher. Pablo Galindo Salgado and I also mentor him.
The three of us intend to continue after his promotion to help him deal with his new responsibilities. In the first month, we will require him to ask us before merging anything until he is used to the process.
Vote process
As a reminder from PEP 13 regarding voting rules:
It is granted by receiving at least two-thirds positive votes in a core team vote that is open for one week and with no veto by the Steering Council.
I strongly support Diego’s promotion. He brings deep expertise in ARM architecture and shows great energy and dedication across the CPython project, particularly through his recent contributions to the JIT work. I’m confident he will continue to add significant value to the CPython project.
Unsurprisingly, I’m really excited to support Diego’s promotion to core developer. I’ve been mentoring him together with Łukasz and during this time he’s proven to be technically excellent and thorough in his work, which covers a lot of different areas. What really sets Diego apart in my opinion is how professional and kind he is in everything he does- he genuinely cares about Python and the community. I think that everyone who has interacted with him can see it right away.
He approaches problems thoughtfully and collaborates well with others, always keeping the project’s best interests in mind. Diego consistently demonstrates not just technical skills but also a deep understanding of what makes our community work always with a super positive attitude.
He’s a fantastic human being, and I cannot wait to call him a fantastic core developer.
Diego is an excellent collaborator and engineer. I’ve had the pleasure of working with him on several JIT tasks and he’s awesome. He would be an excellent addition to our team!
Diego will be a great addition to the team. He’s a fast learner who’s super easy to work with, and he has a real depth of knowledge in a few different key areas. If it weren’t for much of the work he’s done, the new 3.14 JIT release binaries probably wouldn’t have shipped this week for the Windows on Arm or macOS M1 targets.
Beyond landing code changes in CPython itself, he has had a very broad positive impact on Python core development in general: getting access to the CI resources we need, planning sprints and conferences, maintaining benchmarking infrastructure, giving talks, etc.
I’m truly honoured — and honestly a bit overwhelmed — to be joining the CPython core team. I’ve learned so much from this community, and I’m incredibly grateful for the opportunity to keep contributing and growing alongside such a talented and generous group of people.
I’ve been using Python since 2006 — it’s been part of my daily life ever since. Becoming part of the team that helps build Python has always felt like a distant dream, something I never thought I’d actually reach. If someone had told me back then that I’d one day be a core developer, I probably would’ve just smiled and shaken my head in disbelief.
After many years of using Python, I felt it was time to give back. That’s how my journey contributing to CPython began. This would not have been possible without the support of my employer, Arm, who has backed me from day one.
Along the way, I’ve had the chance to interact with so many wonderful people — thank you all. I especially want to thank:
@guido, for introducing me to @ambv, who has supported me from the beginning and patiently helped with all my requests;
@pablogsal, for his support and for answering all my (sometimes silly!) questions;
@brandtbucher, for his mentorship and great patience in guiding me through JIT-related work;
The Faster CPython and Meta teams, for including me in regular syncs and for all the collaboration.
This community is something truly special — a unique, welcoming, inclusive, and intellectually stimulating place. I’ll do my best to help keep it that way.
Becoming a core developer is a huge milestone, but I’ve learned that it’s the journey, not the destination that truly matters. The experiences, relationships, and growth I’ve gained along the way are what I value most — and I’m incredibly grateful for every step of it.
