Guiding You through the Rails Source
Rails is your app's biggest dependency and you probably don't know what's going on in there.
tl;dr: I'm a former Rails core member guiding you through complex parts of Rails helping demystify how things work, so you can feel confident in reading more open source, get inspired and level yourself up faster.
There's features you're missing out on entirely, and features you don't know about. There's features you know, but you probably don't know how they work — and whether you feel confident enough to depend on them.
Without knowing what's going on in Rails, upgrades can seem fraught and daunting and it's tougher to know what to do. And then it's the slow drag of never upgrading. We've all been there.
Reading Rails can help untangle all these issues. This is the way I've leveled up in my career.
Wait, who's this?
It's Kasper! 👻 I was on the Rails core team for six years and I've reviewed thousands of contributor pull requests to Rails. I was the 11th contributor when I left core. You can see all my commits here.
I've shipped many features like credentials, form_with, collection caching render partial: "user", collection: users, cached: true, an internal command infrastructure, maintained and grew GlobalID, invented and extracted Kredis and more. I was also a part of shepherding and reviewing tons of other features (sorry, they blur together after the first 1000 😅).
I've also taken Rails further in my own gems like active_record-associated_object, active_job-performs, oaken and action_controller-stashed_redirects as well as in nice_partials & showcase-rails from my work on Bullet Train.
I grew my Ruby & Rails skills primarily from source diving into gems like Rails itself. I find it's a vastly underrated technique for leveling yourself up, so I'm passing on how to do it to you.
Working with Kasper was everything I hoped for, and more! His deep knowledge of Rails and keen eye for domain modeling allowed him to quickly get up to speed with our project, leaving more time for problem-solving. He helped us overcome two major technical challenges we had been putting off for some time. I’m grateful we had the opportunity to work with Kasper and look forward to collaborating with him again.
Jason Charnes, job boardly.
I’ve had the privilege of learning from Kasper over the past few months. Thanks to the tools and techniques he shared, I’ve become much faster at debugging and fixing issues by identifying root causes more efficiently. Additionally, I’m now able to help my teammates get unblocked by applying the problem-solving strategies I gained from my time with him. Kasper’s guidance has had a lasting impact on my ability to contribute effectively to my team.
Francois Buys, Lead Software Engineer at OmbuLabs
Had an amazing 1:1 session with @kaspth.bsky.social yesterday where he helped me riff on a new feature I am about to start building for mycpaconnect.com.
Feeling way more confident now.
The Rails community is fortunate to have experts like him available to help the rest of us as we build.
Zack Gilbert, on Bluesky after having a 1-1 session with me.
Investigating Rails has many benefits
Rails isn't magic 🪄 reading Rails helps dispel the myth that Rails is magic: it's a lot of Ruby, yes, but it is ultimately understandable and honestly not too bad.
Get a better understanding of how to write APIs: reading the source can give you suggestions of how to or how not to structure your Ruby.
Grow your Ruby skills: for many people the Rails internals are vastly outside their comfort zone, which means you can learn from tons of actual Ruby.
Level up faster: you can feel confident that you can pop open pretty much any gem and start learning how it's made. You read way more code than you write, so getting faster at orienting yourself in new code is a force multiplier.
No other dependency is now scary: Rails is your app's biggest dependency, and getting over the fear of diving into it suddenly opens the door to reading pretty much any other gem with confidence.
You can now evaluate other dependencies: are you thinking of adding a new gem? Well, you've read parts of Rails! Now it's not hard to bundle open gem and skim it. This lets you become a prosumer of open source.
All these skills are applicable to your day job: the better you get at reading code you haven't seen before, the less scary your daily codebase gets — yes, even those parts.
What do we cover when we're live?
This is a live 2-hour session over Zoom. I'm limiting this to up to 20 attendees so we can tweak what we're covering based on what people want to know and see.
But I'm broad strokes, I'm thinking we'll dive into:
Active Record associations & reflections
Active Record SQL generation via ARel
Action Controller and breaking down the overall structure
Action View and how the view rendering works in broad strokes
Active Support callbacks
Action Dispatch routing
Railties + Engines & what they are
We can tweak these depending on the audience too.
I'm also thinking we do around 1h30min of material and then a Q&A for the remaining 30min. We may tweak this as we go too.
The call is not recorded and you're not required to be on video or talk. You can send in questions beforehand via Bluesky/Mastodon, or in the chat while we're live.
Early Access
This tour is early access because I need practice and I learn best by doing. I'm still figuring out the overall structure and how deep go to into each subject.
I'm confident in my ability to explain things though and that this will help you level up in your career. There just may be some rough corners. You're getting 80% of the value at maybe 30% of the cost.
The early very-good price reflects all this too.
What do I tell my boss?
If you're a boss reading this, investing in your team via training improves your company’s output, but also makes your team feel rightly valued & supported. Spending on training is also tax-deductible.
Here's a Slack template you can send over:
Hey {boss}, I've come across a live 2-hour guided tour of the Rails internals. Rails is a our biggest dependency and chockful of features, by investing in this session we can take better strategic advantage of Rails in our app.
This is primarily a tour that focuses on reading code faster & better. As programmers we read a lot of code to build understanding and to prevent mistakes. So training that focuses on reading is a force multiplier for our team.
This tour walks us through really complex parts of Rails and demystifies them for us — doing this on our own would take at least 3x the time.
The tour is run by Kasper Timm Hansen who was on who helped steer the framework while being on the Rails core team. He also shipped many features and reviewed & merged thousands of pull requests to Rails.
It's early access and $129.
Anything else?
I'm also available for consulting on Rails projects and 1-1 consulting, you can book here https://savvycal.com/kaspth