Go Meetup #24

Hosted by Sky Czech Republic.

Doors are open from 5:30 pm, talks will start at 6:00 pm.

1. Marek Svitok (Sky) - Go Interfaces Under the Hood: Why nil Isn’t Always nil

Go interfaces are one of the language's most powerful features, but also a source of many subtle bugs and design questions.
In this talk, we will explore why Go encourages returning concrete types instead of interfaces, what problem tools like ireturn are trying to prevent, and why an interface containing a nil value is not necessarily equal to nil.
We will look under the hood at interface values, understand the relationship between types, values, and method sets, and see how the compiler decides whether a type implements an interface.
The talk will also explain the difference between value and pointer receivers, why T and *T behave differently, and how these details shape idiomatic Go API design.

2. Ladislav Prskavec (Everpure) - What is new in Go 1.27

Go 1.27 is a release where the parts that matter most are not the language features. We will start with the three changes most likely to reach a service already in production: `go test` now runs the `stdversion` vet check by default, `encoding/json/v2` graduated from experiment so the classic `encoding/json` runs on the new implementation with nothing to import, and two quieter behaviour changes — time channels are now always unbuffered, and `http.Response.Body` drains itself on close.
Then the parts worth adopting deliberately: `uuid` in the standard library, the `goroutineleak` profile graduating alongside goroutine labels that now appear in crash dumps and `SIGQUIT` tracebacks, `httptest.NewTestServer` running without real TCP ports, and the new `go fix` modernizers for mechanical migrations. Performance comes last — size-specialized allocation makes small allocations up to 30% faster, worth roughly 1% overall and 60 KB of extra binary — followed by the language changes themselves: generic methods, promoted-field selectors in struct literals, and wider function type inference.

By attending the event I agree that photographs and video recordings from this event may be used by Sky Czech Republic for employer branding and promotional purposes across company websites, career pages, social media, third-party profiles, and other communication materials.