- kube-proxy: a configuration file specified via `--config` is now loaded with strict deserialization, which fails if the config file contains duplicate or unknown fields. This protects against accidentally running with config files that are malformed, mis-indented, or have typos in field names, and getting unexpected behavior....

* Performance test framework and basic tests for the IPAM controller, to simulate behavior of the four supported modes under lightly loaded and loaded conditions, where load is defined as the number of operations to perform as against the configured kubernetes. ([#61143](https://github.com/kubernetes/kubernetes/pull/61143), [@satyasm](https://github.com/satyasm))

- Kubeadm now prints warnings instead of throwing errors if the current system time is outside of the NotBefore and NotAfter bounds of a loaded certificate.  ([#94504](https://github.com/kubernetes/kubernetes/pull/94504), [@neolit123](https://github.com/neolit123))

- Reduce API server memory when many CRDs are loaded by sharing a single etcd3 client logger across all clients ([#111648](https://github.com/kubernetes/kubernetes/pull/111648), [@negz](https://github.com/negz)) [SIG API Machinery]

- kubeadm: fix "certificate-authority" files not being pre-loaded when using file discovery ([#80966](https://github.com/kubernetes/kubernetes/pull/80966), [@neolit123](https://github.com/neolit123))

- Kubernetes 1.23 is now built with go1.19.4. To match behavior of previous Kubernetes 1.23 patch releases:
  - `kube-apiserver` defaults the GOGC setting to 63, to approximate go1.17 garbage collection memory performance in heavily loaded API servers

- Fixed a regression since 1.24 in the scheduling framework when overriding MultiPoint plugins (e.g. default plugins).
  The incorrect loop logic might lead to a plugin being loaded multiple times, consequently preventing any Pod from being scheduled, which is unexpected. ([#122370](https://github.com/kubernetes/kubernetes/pull/122370), [@caohe](https://github.com/caohe)) [SIG Scheduling]

- Reduce API server memory when many CRDs are loaded by sharing a single etcd3 client logger across all clients ([#111650](https://github.com/kubernetes/kubernetes/pull/111650), [@negz](https://github.com/negz)) [SIG API Machinery]

- [`KT-59308`](https://youtrack.jetbrains.com/issue/KT-59308) Auto-generate the IrFactory interface

### JS. Tools

- [`KT-44838`](https://youtrack.jetbrains.com/issue/KT-44838) Kotlin/JS source-map-loader slow performance since 1.4.0

### JavaScript

#### New Features

- [`KT-58684`](https://youtrack.jetbrains.com/issue/KT-58684) KJS: ES15 classes — creating instance by class

#### Performance Improvements

*   The output for kubectl describe networkpolicy * has been enhanced to be more useful. ([#46951](https://github.com/kubernetes/kubernetes/pull/46951),[ @aanm](https://github.com/aanm))
*   Kernel modules are now loaded automatically inside a kube-proxy pod ([#52003](https://github.com/kubernetes/kubernetes/pull/52003),[ @vfreex](https://github.com/vfreex))