Jon Calhoun

Interested in learning to code in 2025? Here's some of my tips & advice. 🧵

@kevinxu Trying to rage bait people? I’ve heard more than one rich person express regrets of prioritizing work over everything else. Typically happens when life event causes them to reflect. Eg a close death or health issues that prevent them from enjoying their wealth.

“No one dies wishing they worked more.” Funny how I’ve never heard a rich person say “I worked too hard.” 🤔

Want to learn #golang in 2026? My courses are on sale! Web Development with Go - usegolang.com Test with Go - testwithgo.com Save 40% on either course until Jan 10th. Gophercises.com is free and a great way to practice as you learn.

I'm hiring for senior Go engineers to join us at @ona_hq! If you are: - AI native; using tools like Cursor, Claude code and Ona daily. - Are excited about building AI agents and the mission control platform that they will run on, entirely in Go. - Have 3-5 years of production Go experience. - Are based in London (remote Europe available too for exceptional folks). Then I'd love to have a virtual coffee with you and see if there is a mutual fit here. Drop me a DM. NOTE: We cannot sponsor visas right now so if you are not already located in Europe then please do not message as there will not be any exceptions.

"Mac usability is characterized by its user-friendly, intuitive interface..." says nobody ever when trying to disable reactions on all video apps. 😫

If you haven't already, fill out the Go Developer Survey! Regardless of your experience level, it helps the Go team plan for the future. google.qualtrics.com/jfe/form/SV_3w…

Did you know that Go's encoding/json package isn't case-sensitive when parsing JSON keys? This is one of the defaults proposed to change in Go's new json/v2 package. #golang #json

In Go, ExampleXxx functions double as docs & tests. ✅ Tests verify code is working by comparing the output. 📖 godocs embed runnable examples, making it easier for devs to get started. #golang #testing

There are a number of reasons for this. For instance, perhaps the legal team won't approve a third party lib due to issues with the license. Or perhaps the team experienced issues in the past with bloat from third party libs and found the most reliable way to avoid it was to strongly discourage any third party libs. Or maybe a large org had a problem of every project using a different set of third party libraries, which caused a disconnect between teams and made it harder for developers to help out other projects internally. Opting to instead build a few of the most common tools internally could be a net positive here. Or maybe the team had issues in the past with third party libraries being incredibly slow to address security concerns, and opted to use their own library rather than try to monitor code they didn't write. I suspect a lot of this mindset stems from the idiom, "A little copying is better than a little dependency." (see youtube.com/watch?v=PAAkCS…) The idea isn't that we should never use dependencies, but rather we should really weigh the pros & cons of using one, where in many other languages developers always default to adding dependencies, oftentimes to their own detriment. The case of writing your own assert library isn't that wild. Most projects only need ~10 different assertions, and you could pretty easily make the argument that importing a library for 10 simple functions is equally odd.

@joncalhoun I don't understand this philosophy. "We won't use an external library with assertions, but we'll write our own (probably worse one)" From my observations, this approach is only formed in the Golang community. I haven't encountered it in any other language.

💡 In Go tests, mark helper functions like assertEquals and doRequest with t.Helper() This causes the Go tooling to point to the line where the function was called rather than a line in the helper function, which makes it easier to debug a failing test. #golang

Example: Let's say I have 100 new PPP customers. That means I need to support 100 more users. If I don't have a support staff, chances are 100 PPP sales don't bring in enough $ to hire someone. Instead, I need to take time away from growing the biz to provide support. Not great. On the other hand, if I have a dedicated support person, 100 new customers probably won't overwhelm them, so PPP might be more viable here.

Unpopular Opinion: Parity Purchasing Power (PPP) discounts are like free plans; they only make sense at a certain income/profit level. Otherwise they kill your ability to grow. x.com/levelsio/statu…

@mattyp @sarahzorah @Padday @intercom Some of these roles pay less than pure tech positions, which seems counterintuitive if you want someone who is both technical and has marketing skills. Feels like once someone has enough technical skills they are better off moving to a tech role.

@sarahzorah @Padday @intercom Precisely why I think every dev tool marketer needs to be technical mattpalmer.io/posts/develope…

There is insane demand for people who can understand and explain technology in a compelling way.

@orimdominic_ It can be useful for any helper functions. Setup, teardown, a doRequrest helper to perform an http request, etc.

@joncalhoun Do you still need to use this if yo don't have assert helper functions?

Sometimes orgs/people don’t want to import a big library, and instead they build a small assertion library that they use internally. This advice also applies to set up and tear down functions, along with other helpers. Basically any scenario where you’d rather the test output point to the caller when an error is encountered.

@joncalhoun Do people write custom asserts like this in real projects? I thought it's just for tutorials. In real code, I only see libs like stretchr/testify

@vitu_dev I’ve been trying it out for a month or so and plan to write up some comparisons in the future.

@joncalhoun I see you already switched to GoLand 👀

There are two ways to create paths in Go depending on your needs. 👉 Constructing a file path in Go? Use filepath.Join from the path/filepath package to get OS-specific separators. 👉 Constructing a slash-seperated path, like a URL? Use path.Join from the path package to get the same results regardless of OS. These may appear to be identical if running a unix-based OS, but they will behave differently in a Windows environment. #golang

Is there a #golang playground that simulates running code on Windows? Would be nice for demonstrating OS-specific differences, but I recognize it is a pretty niche.

I'm guessing the blog posts just falsely assumed that it would work without testing, but hoping to verify that. The source code appears to use straight string matching via a map key.

The CrossOriginProtection added in Go 1.25 doesn't appear to support wildcard subdomains (https://*.calhoun.io) for trusted origins, yet I've had a few people point me to blog posts that use a wildcard example. Am I missing something? #golang

GoLand users - what are your favorite features and tips? I’ve been trying it out to do a bit of a comparison, but I want to hear from #golang developers who have been using it for a bit.