tl;dr: Go 1.27 adds three language updates: generic methods, struct literal keys that can reference embedded/nested fields, and generalized function type inference across composite literals, conversions, and channel sends. The standard library gains `encoding/json/v2` (which now backs v1 for faster unmarshaling), post-quantum ML-DSA signatures, native UUID support, and experimental SIMD packages. Runtime improvements include size-specialized allocation cutting small-object costs up to 30%, plus a generally available goroutine leak profiler.