diff --git a/Cargo.toml b/Cargo.toml
index 08a7989e9..8c9fda313 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -22,7 +22,7 @@ edition = "2021"
 rust-version = "1.86"
 
 [workspace.dependencies]
-differential-dataflow = { path = "differential-dataflow", default-features = false, version = "0.20.0" }
+differential-dataflow = { path = "differential-dataflow", default-features = false, version = "0.21.0" }
 timely = { version = "0.28", default-features = false }
 columnar = { version = "0.12", default-features = false }
 #timely = { git = "https://github.com/TimelyDataflow/timely-dataflow" }
diff --git a/differential-dataflow/CHANGELOG.md b/differential-dataflow/CHANGELOG.md
index d1258b899..9e537abd6 100644
--- a/differential-dataflow/CHANGELOG.md
+++ b/differential-dataflow/CHANGELOG.md
@@ -7,6 +7,25 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+## [0.21.0](https://github.com/TimelyDataflow/differential-dataflow/compare/differential-dataflow-v0.20.0...differential-dataflow-v0.21.0) - 2026-03-25
+
+### Added
+
+- `Arranged::as_container` convenience method for extracting non-`Vec` containers from arrangements ([#695](https://github.com/TimelyDataflow/differential-dataflow/pull/695))
+- `Columnation` and `Columnar` implementations for the `Present` zero-sized difference type ([#682](https://github.com/TimelyDataflow/differential-dataflow/pull/682))
+
+### Changed
+
+- Update to timely 0.28 and columnar 0.12 ([#698](https://github.com/TimelyDataflow/differential-dataflow/pull/698))
+- Adopt internal iteration for consolidation, merge batching, and trace building, replacing external iteration that leaked internal types through abstractions ([#689](https://github.com/TimelyDataflow/differential-dataflow/pull/689))
+
+### Fixed
+
+- Eliminate a redundant `arrange` in `propagate` and a double scope-import in `scc` ([#692](https://github.com/TimelyDataflow/differential-dataflow/pull/692))
+
+The main theme of this release is internal iteration: consolidation, merging, and trace building now happen behind trait methods rather than exposing container internals outward.
+Dependency updates track timely 0.28 and columnar 0.12.
+
 ## [0.20.0](https://github.com/TimelyDataflow/differential-dataflow/compare/differential-dataflow-v0.19.1...differential-dataflow-v0.20.0) - 2026-03-05
 
 ### Other
diff --git a/differential-dataflow/Cargo.toml b/differential-dataflow/Cargo.toml
index e961eb3ea..5fda33368 100644
--- a/differential-dataflow/Cargo.toml
+++ b/differential-dataflow/Cargo.toml
@@ -1,7 +1,7 @@
 [package]
 
 name = "differential-dataflow"
-version = "0.20.0"
+version = "0.21.0"
 authors = ["Frank McSherry <fmcsherry@me.com>"]
 
 description = "An incremental data-parallel dataflow platform"
diff --git a/dogsdogsdogs/CHANGELOG.md b/dogsdogsdogs/CHANGELOG.md
index 027c15db6..047d3e2b1 100644
--- a/dogsdogsdogs/CHANGELOG.md
+++ b/dogsdogsdogs/CHANGELOG.md
@@ -7,6 +7,12 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+## [0.21.0](https://github.com/TimelyDataflow/differential-dataflow/compare/differential-dogs3-v0.20.0...differential-dogs3-v0.21.0) - 2026-03-25
+
+### Other
+
+- update Cargo.toml dependencies
+
 ## [0.20.0](https://github.com/TimelyDataflow/differential-dataflow/compare/differential-dogs3-v0.19.1...differential-dogs3-v0.20.0) - 2026-03-05
 
 ### Other
diff --git a/dogsdogsdogs/Cargo.toml b/dogsdogsdogs/Cargo.toml
index 2db38d3e1..e3bd3a5f9 100644
--- a/dogsdogsdogs/Cargo.toml
+++ b/dogsdogsdogs/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "differential-dogs3"
-version = "0.20.0"
+version = "0.21.0"
 authors = ["Frank McSherry <fmcsherry@me.com>"]
 license = "MIT"
 edition.workspace = true