Reflections on ten years of LLVM Weekly


Today, with Issue #522 I'm marking ten years of authoring LLVM Weekly, a newsletter summarising developments on projects under the LLVM umbrella (LLVM, Clang, MLIR, Flang, libcxx, compiler-rt, lld, LLDB, ...). Somehow I've managed to keep up an unbroken streak, publishing every single Monday since the first issue back on Jan 6th 2014 (the first Monday of 2014 - you can also see the format hasn't changed much!). With a milestone like that, now is the perfect moment to jot down some reflections on the newsletter and thoughts for the future.

Motivation and purpose

Way back when I started LLVM Weekly, I'd been working with LLVM for a few years as part of developing and supporting a downstream compiler for a novel research architecture. This was a very educational yet somewhat lonely experience, and I sought to more closely follow upstream LLVM development to keep better abreast of changes that might impact or help my work, to learn more about parts of the compiler I wasn't actively using, and also to feel more of a connection to the wider LLVM community given my compiler work was a solo effort. The calculus for kicking off an LLVM development newsletter was dead simple: I found value in tracking development anyway, the incremental effort to write up and share with others wasn't too great, and I felt quite sure others would benefit as well.

Looking back at my notes (I have a huge Markdown file with daily notes going back to 2011 - a file of this rough size and format is also a good stress test for text editors!) it seems I thought seriously about the idea of starting something up at the beginning of December 2013. I brainstormed the format, looked at other newsletters I might want to emulate, and went ahead and just did it starting in the new year. It really was as simple as that. I figured better to give it a try and stop it if it gets no traction rather than waste lots of time putting out feelers on level of interest and format. As a sidenote, I was delighted to see many of the newsletters I studied at the time are still going: This Week in Rust Perl Weekly (I'll admit this surprised me!), Ubuntu Weekly News, OCaml Weekly News, and Haskell Weekly News.

Readership and content

The basic format of LLVM Weekly is incredibly simple - highlight relevant news articles and blog posts, pick out some forum/mailing discussions (sometimes trying to summarise complex debates - but this is very challenging and time intensive), and highlight some noteworthy commits from across the project. More recently I've taken to advertising the scheduled online sync-ups and office hours for the week. Notably absent are any kind of ads or paid content. I respect that others have made successful businesses in this kind of space, but although I've always written LLVM Weekly on my own personal time I've never felt comfortable trying to monetise other people's attention or my relationship with the community in this way.

The target audience is really anyone with an interest in keeping track of LLVM development, though I don't tend to expand every acronym or give a from-basics explanation for every term, so some familiarity with the project is assumed if you want to understand every line. The newsletter is posted to LLVM's Discourse, to, and delivered direct to people's inboxes. I additionally post on Twitter and on Mastodon linking to each issue. I don't attempt to track open rates or have functioning analytics, so only have a rough idea of readership. There are ~3.5k active subscribers directly to the mailing list, ~7.5k Twitter followers, ~180 followers on Mastodon (introduced much more recently), and an unknown number of people reading via or RSS. I'm pretty confident that I'm not just shouting in the void at least.

There are some gaps or blind spots of course. I make no attempt to try to link to patches that are under-review, even though many might have interesting review discussions because it would simply be too much work to sort through them and if the discussion is particularly contentious or requires input from a wider cross-section of the LLVM community you'd expect an RFC to be posted anyway. Although I do try to highlight MLIR threads or commits, as it's not an area of LLVM I'm working right now I probably miss some things. Thankfully Javed Absar has taken up writing an MLIR newsletter that helps plug those gaps. I'm also not currently trawling through repos under the LLVM GitHub organisation other than the main llvm-project monorepo, though perhaps I should...

I've shied away from reposting job posts as the overhead is just too high. I found dealing with requests to re-advertise (and considering if this is useful to the community) or determining if ads are sufficiently LLVM related just wasnt a good use of time when there's a good alternative. People can check the job post category on LLVM discourse or search for LLVM on their favourite jobs site.

How it works

There are really two questions to be answered here: how I go about writing it each week, and what tools and services are used. In terms of writing:

There's not much to be said on the tooling said, except that I could probably benefit from refreshing my helper scripts. Mail sending is handled by Mailgun, who have changed ownership three times since I started. I handle double opt-in via a simple Python script on the server-side and mail sending costs me $3-5 a month. Otherwise, I generate the static HTML with some scripts that could do with a bit more love. The only other running costs are the domain name fees and a VPS that hosts some other things as well, so quite insignificant compared to the time commitment.

How you can help

I cannot emphasise enough that I'm not an expert on all parts of LLVM, and I'm also only human and can easily miss things. If you did something you think people may be interested in and I failed to cover it, I almost certainly didn't explicitly review it and deem it not worthy. Please do continue to help me out by dropping links and suggestions. Writing commit messages that make it clear if a change has wider impact also helps increase the chance I'll pick it up.

I noted above that it is particularly time consuming to summarise back and forth in lengthy RFC threads. Sometimes people step up and do this and I always try to link to it when this happens. The person who initiated a thread or proposal is best placed write such a summary, and it's also a useful tool to check that you interpreted people's suggestions/feedback correctly, but it can still be helpful if others provide a similar service.

Many people have fed back they find LLVM Weekly useful to stay on top of LLVM developments. This is gratifying, but also a pretty huge responsibility. If you have thoughts on things I could be doing differently to serve the community even better without a big difference in time commitment, I'm always keen to hear ideas and suggestions.

Miscellaneous thoughts

To state the obvious, ten years is kind of a long time. A lot has happened with me in that time - I've got married, we had a son, I co-founded and helped grow a company, and then moved on from that, kicked off the upstream RISC-V LLVM backend, and much more. One of the things I love working with compilers is that there's always new things to learn, and writing LLVM Weekly helps me learn at least a little more each week in areas outside of where I'm currently working. There's been a lot of changes in LLVM as well. Off the top off my head: there's been the move from SVN to Git, moving the Git repo to GitHub, moving from Phabricator to GitHub PRs, Bugzilla to GitHub issues, mailing lists to Discourse, relicensing to Apache 2.0 with LLVM exception, the wider adoption of office hours and area-specific sync-up calls, and more. I think even the LLVM Foundation was set up a little bit after LLVM Weekly started. It's comforting to see the website design remains unchanged though!

It's also been a time period where I've become increasingly involved in LLVM. Upstream work - most notably initiating the RISC-V LLVM backend, organising an LLVM conference, many talks, serving on various program committees for LLVM conferences, etc etc. When I started I felt a lot like someone outside the community looking in and documenting what I saw. That was probably accurate too, given the majority of my work was downstream. While I don't feel like an LLVM "insider" (if such a thing exists?!), I certainly feel a lot more part of the community than I did way back then.

An obvious question is whether there are other ways of pulling together the newsletter that are worth pursuing. My experience with large language models so far has been that they haven't been very helpful in reducing the effort for the more time consuming aspects of producing LLVM Weekly, but perhaps that will change in the future. If I could be automated away then that's great - perhaps I'm misjudging how much of my editorial input is signal rather than just noise, but I don't think we're there yet for AI. More collaborative approaches to producing content would be another avenue to explore. For the current format, the risk is that the communication overhead and stress of seeing if various contributions actually materialise before the intended publication date is quite high. If I did want to spread the load or hand it over, then a rotating editorship would probably be most interesting to me. Even if multiple people contribute, each week a single would act as a backstop to make sure something goes out.

The unbroken streak of LLVM Weekly editions each Monday has become a bit totemic. It's certainly not always convenient having this fixed commitment, but it can also be nice to have this rhythm to the week. Even if it's a bad week, at least it's something in the bag that people seem to appreciate. Falling into bad habits and frequently missing weeks would be good for nobody, but I suspect that a schedule that allowed the odd break now and then would be just fine. Either way, I feel a sense of relief having hit the 10 year unbroken streak. I don't intend to start skipping weeks, but should life get in the way and the streak gets broken I'll feel rather more relaxed about it having hit that arbitrary milestone.

Looking forwards and thanks

So what's next? LLVM Weekly continues, much as before. I don't know of I'll still be writing it in another 10 years time, but I'm not planning to stop soon. If it ceases to be a good use of my time, ceases to have values for others, or I find there's a better way of generating similar impact then it would only be logical to move on. But for now, onwards and upwards.

Many thanks are due. Thank you to the people who make LLVM what it is - both technically and in terms of its community that I've learned so much from. Thank you to Igalia where I work for creating an environment where I'm privileged enough to be paid to contribute upstream to LLVM (get in touch if you have LLVM needs!). Thanks to my family for ongoing support and of course putting up with the times my LLVM Weekly commitment is inconvenient. Thank you to everyone who has been reading LLVM Weekly and especially those sending in feedback or tips or suggestions for future issues.

On a final note, if you've got this far you should make sure you are subscribed to LLVM Weekly and follow on Mastodon or on Twitter.