diff --git a/.github/workflows/Test.yml b/.github/workflows/Test.yml
index 89223f597..bb7cbd4d8 100644
--- a/.github/workflows/Test.yml
+++ b/.github/workflows/Test.yml
@@ -16,8 +16,8 @@ concurrency:
   cancel-in-progress: ${{ startsWith(github.ref, 'refs/pull/') }}
 
 jobs:
-  test-DI:
-    name: ${{ matrix.version }} - DI (${{ matrix.group }})
+  test-DI-Core:
+    name: ${{ matrix.version }} - DI Core (${{ matrix.group }})
     runs-on: ubuntu-latest
     if: ${{ !contains(github.event.pull_request.labels.*.name, 'skipci') }}
     timeout-minutes: 120
@@ -32,25 +32,9 @@ jobs:
           - '1.11'
           - '1.12'
         group:
-          - Core/Internals
-          - Back/DifferentiateWith
-          - Core/SimpleFiniteDiff
-          - Back/SparsityDetector
-          - Core/ZeroBackends
-          - Back/ChainRules
-          # - Back/Diffractor
-          - Back/Enzyme
-          - Back/FastDifferentiation
-          - Back/FiniteDiff
-          - Back/FiniteDifferences
-          - Back/ForwardDiff
-          - Back/GTPSA
-          - Back/Mooncake
-          - Back/PolyesterForwardDiff
-          - Back/ReverseDiff
-          - Back/Symbolics
-          - Back/Tracker
-          - Back/Zygote
+          - Internals
+          - SimpleFiniteDiff
+          - ZeroBackends
         skip_lts:
           - ${{ github.event.pull_request.draft }}
         skip_pre:
@@ -60,13 +44,8 @@ jobs:
             version: '1.10'
           - skip_pre: true
             version: '1.12'
-          - version: '1.11'
-            group: Back/ChainRules
-          - version: '1.12'
-            group: Back/Enzyme
-          - version: '1.12'
-            group: Back/DifferentiateWith
     env:
+      JULIA_DI_TEST_TYPE: 'Core'
       JULIA_DI_TEST_GROUP: ${{ matrix.group }}
       JULIA_DI_PR_DRAFT: ${{ github.event.pull_request.draft }}
     steps:
@@ -79,7 +58,6 @@ jobs:
       - name: Install dependencies & run tests
         run: julia --color=yes -e '
           using Pkg;
-          Pkg.Registry.update();
           Pkg.activate("./DifferentiationInterface/test");
           if VERSION < v"1.11";
           Pkg.rm("DifferentiationInterfaceTest");
@@ -104,6 +82,81 @@ jobs:
           token: ${{ secrets.CODECOV_TOKEN }}
           fail_ci_if_error: false
 
+  test-DI-Backend:
+    name: ${{ matrix.version }} - DI Back (${{ matrix.group }})
+    runs-on: ubuntu-latest
+    if: ${{ !contains(github.event.pull_request.labels.*.name, 'skipci') }}
+    timeout-minutes: 120
+    permissions: # needed to allow julia-actions/cache to proactively delete old caches that it has created
+      actions: write
+      contents: read
+    strategy:
+      fail-fast: false # TODO: toggle
+      matrix:
+        version:
+          - '1.10'
+          - '1.11'
+          - '1.12'
+        group:
+          - ChainRules
+          - DifferentiateWith
+          # - Diffractor
+          - Enzyme
+          - FastDifferentiation
+          - FiniteDiff
+          - FiniteDifferences
+          - ForwardDiff
+          - GTPSA
+          - Mooncake
+          - PolyesterForwardDiff
+          - ReverseDiff
+          - SparsityDetector
+          - Symbolics
+          - Tracker
+          - Zygote
+        skip_lts:
+          - ${{ github.event.pull_request.draft }}
+        skip_pre:
+          - ${{ github.event.pull_request.draft }}
+        exclude:
+          - skip_lts: true
+            version: '1.10'
+          - skip_pre: true
+            version: '1.12'
+          - version: '1.11'
+            group: ChainRules
+          - version: '1.12'
+            group: Enzyme
+          - version: '1.12'
+            group: DifferentiateWith
+    env:
+      JULIA_DI_TEST_TYPE: 'Back'
+      JULIA_DI_TEST_GROUP: ${{ matrix.group }}
+      JULIA_DI_PR_DRAFT: ${{ github.event.pull_request.draft }}
+    steps:
+      - uses: actions/checkout@v5
+      - uses: julia-actions/setup-julia@v2
+        with:
+          version: ${{ matrix.version }}
+          arch: x64
+      - uses: julia-actions/cache@v2
+      - name: Install dependencies & run tests
+        run: julia --code-coverage=user --color=yes -e '
+          using Pkg;
+          group = ENV["JULIA_DI_TEST_GROUP"];
+          Pkg.activate("./DifferentiationInterface/test/Back/$group");
+          Pkg.develop([PackageSpec(path="./DifferentiationInterface"), PackageSpec(path="./DifferentiationInterfaceTest")]);
+          include("./DifferentiationInterface/test/Back/run_backend.jl");'
+      - uses: julia-actions/julia-processcoverage@v1
+        with:
+          directories: ./DifferentiationInterface/src,./DifferentiationInterface/ext,./DifferentiationInterface/test
+      - uses: codecov/codecov-action@v5
+        with:
+          files: lcov.info
+          flags: DI
+          token: ${{ secrets.CODECOV_TOKEN }}
+          fail_ci_if_error: false
+
   test-DIT:
     name: ${{ matrix.version }} - DIT (${{ matrix.group }})
     runs-on: ubuntu-latest
diff --git a/DifferentiationInterface/test/Back/ChainRules/Project.toml b/DifferentiationInterface/test/Back/ChainRules/Project.toml
new file mode 100644
index 000000000..8cb909466
--- /dev/null
+++ b/DifferentiationInterface/test/Back/ChainRules/Project.toml
@@ -0,0 +1,10 @@
+[deps]
+ADTypes = "47edcb42-4c32-4615-8424-f2b9edc5f35b"
+ChainRules = "082447d4-558c-5d27-93f4-14fc19e9eca2"
+DifferentiationInterface = "a0c0ee7d-e4b9-4e03-894e-1c5f64a51d63"
+DifferentiationInterfaceTest = "a82114a7-5aa3-49a8-9643-716bb13727a3"
+ExplicitImports = "7d51a73a-1435-4ff3-83d9-f097790105c7"
+SparseConnectivityTracer = "9f842d2f-2579-4b1d-911e-f412cf18a3f5"
+SparseMatrixColorings = "0a514795-09f3-496d-8182-132a7b665d35"
+Test = "8dfed614-e22c-5e08-85e1-65c5234f0b40"
+Zygote = "e88e6eb3-aa80-5325-afca-941959d7151f"
diff --git a/DifferentiationInterface/test/Back/ChainRules/zygote.jl b/DifferentiationInterface/test/Back/ChainRules/test.jl
similarity index 85%
rename from DifferentiationInterface/test/Back/ChainRules/zygote.jl
rename to DifferentiationInterface/test/Back/ChainRules/test.jl
index 9722220f4..b484a15cb 100644
--- a/DifferentiationInterface/test/Back/ChainRules/zygote.jl
+++ b/DifferentiationInterface/test/Back/ChainRules/test.jl
@@ -1,7 +1,5 @@
-using Pkg
-Pkg.add(["ChainRulesCore", "Zygote"])
+include("../../testutils.jl")
 
-using ChainRulesCore
 using DifferentiationInterface, DifferentiationInterfaceTest
 using Test
 using Zygote: ZygoteRuleConfig
@@ -9,8 +7,6 @@ using Zygote: ZygoteRuleConfig
 using ExplicitImports
 check_no_implicit_imports(DifferentiationInterface)
 
-LOGGING = get(ENV, "CI", "false") == "false"
-
 for backend in [AutoChainRules(ZygoteRuleConfig())]
     @test check_available(backend)
     @test !check_inplace(backend)
diff --git a/DifferentiationInterface/test/Back/DifferentiateWith/Project.toml b/DifferentiationInterface/test/Back/DifferentiateWith/Project.toml
new file mode 100644
index 000000000..8fc6a2707
--- /dev/null
+++ b/DifferentiationInterface/test/Back/DifferentiateWith/Project.toml
@@ -0,0 +1,14 @@
+[deps]
+ADTypes = "47edcb42-4c32-4615-8424-f2b9edc5f35b"
+ChainRulesTestUtils = "cdddcdb0-9152-4a09-a978-84456f9df70a"
+DifferentiationInterface = "a0c0ee7d-e4b9-4e03-894e-1c5f64a51d63"
+DifferentiationInterfaceTest = "a82114a7-5aa3-49a8-9643-716bb13727a3"
+ExplicitImports = "7d51a73a-1435-4ff3-83d9-f097790105c7"
+FiniteDiff = "6a86dc24-6348-571c-b903-95158fe2bd41"
+ForwardDiff = "f6369f11-7733-5829-9624-2563aa707210"
+Mooncake = "da2b9cff-9c12-43a0-ae48-6db2b0edb7d6"
+SparseConnectivityTracer = "9f842d2f-2579-4b1d-911e-f412cf18a3f5"
+SparseMatrixColorings = "0a514795-09f3-496d-8182-132a7b665d35"
+StableRNGs = "860ef19b-820b-49d6-a774-d7a799459cd3"
+Test = "8dfed614-e22c-5e08-85e1-65c5234f0b40"
+Zygote = "e88e6eb3-aa80-5325-afca-941959d7151f"
diff --git a/DifferentiationInterface/test/Back/DifferentiateWith/test.jl b/DifferentiationInterface/test/Back/DifferentiateWith/test.jl
index 04d9f5b99..860d5e85f 100644
--- a/DifferentiationInterface/test/Back/DifferentiateWith/test.jl
+++ b/DifferentiationInterface/test/Back/DifferentiateWith/test.jl
@@ -1,5 +1,4 @@
-using Pkg
-Pkg.add(["ChainRulesTestUtils", "FiniteDiff", "ForwardDiff", "Zygote", "Mooncake"])
+include("../../testutils.jl")
 
 using ChainRulesTestUtils: ChainRulesTestUtils
 using DifferentiationInterface, DifferentiationInterfaceTest
@@ -11,8 +10,6 @@ using Mooncake: Mooncake
 using StableRNGs
 using Test
 
-LOGGING = get(ENV, "CI", "false") == "false"
-
 struct ADBreaker{F}
     f::F
 end
diff --git a/DifferentiationInterface/test/Back/Diffractor/test.jl b/DifferentiationInterface/test/Back/Diffractor/test.jl
deleted file mode 100644
index 57be809ea..000000000
--- a/DifferentiationInterface/test/Back/Diffractor/test.jl
+++ /dev/null
@@ -1,23 +0,0 @@
-using Pkg
-Pkg.add("Diffractor")
-
-using DifferentiationInterface, DifferentiationInterfaceTest
-using Diffractor: Diffractor
-using Test
-
-using ExplicitImports
-check_no_implicit_imports(DifferentiationInterface)
-
-LOGGING = get(ENV, "CI", "false") == "false"
-
-for backend in [AutoDiffractor()]
-    @test check_available(backend)
-    @test !check_inplace(backend)
-end
-
-test_differentiation(
-    AutoDiffractor(),
-    default_scenarios(; linalg = false);
-    excluded = SECOND_ORDER,
-    logging = LOGGING,
-);
diff --git a/DifferentiationInterface/test/Back/Enzyme/Project.toml b/DifferentiationInterface/test/Back/Enzyme/Project.toml
new file mode 100644
index 000000000..ee903053a
--- /dev/null
+++ b/DifferentiationInterface/test/Back/Enzyme/Project.toml
@@ -0,0 +1,11 @@
+[deps]
+ADTypes = "47edcb42-4c32-4615-8424-f2b9edc5f35b"
+DifferentiationInterface = "a0c0ee7d-e4b9-4e03-894e-1c5f64a51d63"
+DifferentiationInterfaceTest = "a82114a7-5aa3-49a8-9643-716bb13727a3"
+Enzyme = "7da242da-08ed-463a-9acd-ee780be4f1d9"
+ExplicitImports = "7d51a73a-1435-4ff3-83d9-f097790105c7"
+LinearAlgebra = "37e2e46d-f89d-539d-b4ee-838fcccc9c8e"
+SparseConnectivityTracer = "9f842d2f-2579-4b1d-911e-f412cf18a3f5"
+SparseMatrixColorings = "0a514795-09f3-496d-8182-132a7b665d35"
+StaticArrays = "90137ffa-7385-5640-81b9-e52037218182"
+Test = "8dfed614-e22c-5e08-85e1-65c5234f0b40"
diff --git a/DifferentiationInterface/test/Back/Enzyme/test.jl b/DifferentiationInterface/test/Back/Enzyme/test.jl
index 892ac6c78..f80fc63c3 100644
--- a/DifferentiationInterface/test/Back/Enzyme/test.jl
+++ b/DifferentiationInterface/test/Back/Enzyme/test.jl
@@ -1,7 +1,4 @@
-# see https://github.com/JuliaDiff/DifferentiationInterface.jl/issues/855
-
-using Pkg
-Pkg.add("Enzyme")
+include("../../testutils.jl")
 
 using ADTypes: ADTypes
 using DifferentiationInterface, DifferentiationInterfaceTest
@@ -14,8 +11,6 @@ using Test
 using ExplicitImports
 check_no_implicit_imports(DifferentiationInterface)
 
-LOGGING = get(ENV, "CI", "false") == "false"
-
 backends = [
     AutoEnzyme(; mode = nothing),
     AutoEnzyme(; mode = Enzyme.Forward),
diff --git a/DifferentiationInterface/test/Back/FastDifferentiation/Project.toml b/DifferentiationInterface/test/Back/FastDifferentiation/Project.toml
new file mode 100644
index 000000000..b7160b43f
--- /dev/null
+++ b/DifferentiationInterface/test/Back/FastDifferentiation/Project.toml
@@ -0,0 +1,10 @@
+[deps]
+ADTypes = "47edcb42-4c32-4615-8424-f2b9edc5f35b"
+DifferentiationInterface = "a0c0ee7d-e4b9-4e03-894e-1c5f64a51d63"
+DifferentiationInterfaceTest = "a82114a7-5aa3-49a8-9643-716bb13727a3"
+ExplicitImports = "7d51a73a-1435-4ff3-83d9-f097790105c7"
+FastDifferentiation = "eb9bf01b-bf85-4b60-bf87-ee5de06c00be"
+LinearAlgebra = "37e2e46d-f89d-539d-b4ee-838fcccc9c8e"
+SparseConnectivityTracer = "9f842d2f-2579-4b1d-911e-f412cf18a3f5"
+SparseMatrixColorings = "0a514795-09f3-496d-8182-132a7b665d35"
+Test = "8dfed614-e22c-5e08-85e1-65c5234f0b40"
diff --git a/DifferentiationInterface/test/Back/FastDifferentiation/fastdifferentiation.jl b/DifferentiationInterface/test/Back/FastDifferentiation/test.jl
similarity index 93%
rename from DifferentiationInterface/test/Back/FastDifferentiation/fastdifferentiation.jl
rename to DifferentiationInterface/test/Back/FastDifferentiation/test.jl
index 86d903faa..e42dc5132 100644
--- a/DifferentiationInterface/test/Back/FastDifferentiation/fastdifferentiation.jl
+++ b/DifferentiationInterface/test/Back/FastDifferentiation/test.jl
@@ -1,5 +1,4 @@
-using Pkg
-Pkg.add("FastDifferentiation")
+include("../../testutils.jl")
 
 using DifferentiationInterface, DifferentiationInterfaceTest
 using SparseMatrixColorings
@@ -10,8 +9,6 @@ using Test
 using ExplicitImports
 check_no_implicit_imports(DifferentiationInterface)
 
-LOGGING = get(ENV, "CI", "false") == "false"
-
 for backend in [AutoFastDifferentiation(), AutoSparse(AutoFastDifferentiation())]
     @test check_available(backend)
     @test check_inplace(backend)
diff --git a/DifferentiationInterface/test/Back/FiniteDiff/Project.toml b/DifferentiationInterface/test/Back/FiniteDiff/Project.toml
new file mode 100644
index 000000000..e8c5eb3bc
--- /dev/null
+++ b/DifferentiationInterface/test/Back/FiniteDiff/Project.toml
@@ -0,0 +1,9 @@
+[deps]
+ADTypes = "47edcb42-4c32-4615-8424-f2b9edc5f35b"
+DifferentiationInterface = "a0c0ee7d-e4b9-4e03-894e-1c5f64a51d63"
+DifferentiationInterfaceTest = "a82114a7-5aa3-49a8-9643-716bb13727a3"
+ExplicitImports = "7d51a73a-1435-4ff3-83d9-f097790105c7"
+FiniteDiff = "6a86dc24-6348-571c-b903-95158fe2bd41"
+SparseConnectivityTracer = "9f842d2f-2579-4b1d-911e-f412cf18a3f5"
+SparseMatrixColorings = "0a514795-09f3-496d-8182-132a7b665d35"
+Test = "8dfed614-e22c-5e08-85e1-65c5234f0b40"
diff --git a/DifferentiationInterface/test/Back/FiniteDiff/benchmark.jl b/DifferentiationInterface/test/Back/FiniteDiff/benchmark.jl
index 96a0cb61e..cc24f47dc 100644
--- a/DifferentiationInterface/test/Back/FiniteDiff/benchmark.jl
+++ b/DifferentiationInterface/test/Back/FiniteDiff/benchmark.jl
@@ -1,5 +1,4 @@
 using Pkg
-Pkg.add("FiniteDiff")
 
 using ADTypes: ADTypes
 using DifferentiationInterface, DifferentiationInterfaceTest
@@ -8,8 +7,6 @@ import DifferentiationInterfaceTest as DIT
 using FiniteDiff: FiniteDiff
 using Test
 
-LOGGING = get(ENV, "CI", "false") == "false"
-
 @testset "Benchmarking sparse" begin
     filtered_sparse_scenarios = filter(sparse_scenarios(; band_sizes = [])) do scen
         DIT.function_place(scen) == :in &&
diff --git a/DifferentiationInterface/test/Back/FiniteDiff/test.jl b/DifferentiationInterface/test/Back/FiniteDiff/test.jl
index a7f5ad42f..d2a63f03e 100644
--- a/DifferentiationInterface/test/Back/FiniteDiff/test.jl
+++ b/DifferentiationInterface/test/Back/FiniteDiff/test.jl
@@ -1,5 +1,4 @@
-using Pkg
-Pkg.add("FiniteDiff")
+include("../../testutils.jl")
 
 using DifferentiationInterface, DifferentiationInterfaceTest
 using DifferentiationInterface: DenseSparsityDetector
@@ -10,8 +9,6 @@ using Test
 using ExplicitImports
 check_no_implicit_imports(DifferentiationInterface)
 
-LOGGING = get(ENV, "CI", "false") == "false"
-
 for backend in [AutoFiniteDiff()]
     @test check_available(backend)
     @test check_inplace(backend)
@@ -114,3 +111,5 @@ end;
     @test prep.relstep_g == 0.1
     @test prep.relstep_h == 0.1
 end
+
+include("benchmark.jl")
diff --git a/DifferentiationInterface/test/Back/FiniteDifferences/Project.toml b/DifferentiationInterface/test/Back/FiniteDifferences/Project.toml
new file mode 100644
index 000000000..7082f1ff7
--- /dev/null
+++ b/DifferentiationInterface/test/Back/FiniteDifferences/Project.toml
@@ -0,0 +1,9 @@
+[deps]
+ADTypes = "47edcb42-4c32-4615-8424-f2b9edc5f35b"
+DifferentiationInterface = "a0c0ee7d-e4b9-4e03-894e-1c5f64a51d63"
+DifferentiationInterfaceTest = "a82114a7-5aa3-49a8-9643-716bb13727a3"
+ExplicitImports = "7d51a73a-1435-4ff3-83d9-f097790105c7"
+FiniteDifferences = "26cc04aa-876d-5657-8c51-4c34ba976000"
+SparseConnectivityTracer = "9f842d2f-2579-4b1d-911e-f412cf18a3f5"
+SparseMatrixColorings = "0a514795-09f3-496d-8182-132a7b665d35"
+Test = "8dfed614-e22c-5e08-85e1-65c5234f0b40"
diff --git a/DifferentiationInterface/test/Back/FiniteDifferences/test.jl b/DifferentiationInterface/test/Back/FiniteDifferences/test.jl
index 7157a043c..ba585dc0c 100644
--- a/DifferentiationInterface/test/Back/FiniteDifferences/test.jl
+++ b/DifferentiationInterface/test/Back/FiniteDifferences/test.jl
@@ -1,5 +1,4 @@
-using Pkg
-Pkg.add("FiniteDifferences")
+include("../../testutils.jl")
 
 using DifferentiationInterface, DifferentiationInterfaceTest
 using FiniteDifferences: FiniteDifferences
@@ -8,8 +7,6 @@ using Test
 using ExplicitImports
 check_no_implicit_imports(DifferentiationInterface)
 
-LOGGING = get(ENV, "CI", "false") == "false"
-
 for backend in [AutoFiniteDifferences(; fdm = FiniteDifferences.central_fdm(3, 1))]
     @test check_available(backend)
     @test !check_inplace(backend)
diff --git a/DifferentiationInterface/test/Back/ForwardDiff/Project.toml b/DifferentiationInterface/test/Back/ForwardDiff/Project.toml
new file mode 100644
index 000000000..c780a32bc
--- /dev/null
+++ b/DifferentiationInterface/test/Back/ForwardDiff/Project.toml
@@ -0,0 +1,12 @@
+[deps]
+ADTypes = "47edcb42-4c32-4615-8424-f2b9edc5f35b"
+ComponentArrays = "b0b7db55-cfe3-40fc-9ded-d10e2dbeff66"
+DifferentiationInterface = "a0c0ee7d-e4b9-4e03-894e-1c5f64a51d63"
+DifferentiationInterfaceTest = "a82114a7-5aa3-49a8-9643-716bb13727a3"
+ExplicitImports = "7d51a73a-1435-4ff3-83d9-f097790105c7"
+ForwardDiff = "f6369f11-7733-5829-9624-2563aa707210"
+JLArrays = "27aeb0d3-9eb9-45fb-866b-73c2ecf80fcb"
+SparseConnectivityTracer = "9f842d2f-2579-4b1d-911e-f412cf18a3f5"
+SparseMatrixColorings = "0a514795-09f3-496d-8182-132a7b665d35"
+StaticArrays = "90137ffa-7385-5640-81b9-e52037218182"
+Test = "8dfed614-e22c-5e08-85e1-65c5234f0b40"
diff --git a/DifferentiationInterface/test/Back/ForwardDiff/benchmark.jl b/DifferentiationInterface/test/Back/ForwardDiff/benchmark.jl
index 256c8aaa2..a4a0b25f0 100644
--- a/DifferentiationInterface/test/Back/ForwardDiff/benchmark.jl
+++ b/DifferentiationInterface/test/Back/ForwardDiff/benchmark.jl
@@ -1,5 +1,4 @@
 using Pkg
-Pkg.add("ForwardDiff")
 
 using ADTypes: ADTypes
 using DifferentiationInterface, DifferentiationInterfaceTest
@@ -9,8 +8,6 @@ using ForwardDiff: ForwardDiff
 using StaticArrays: StaticArrays, @SVector
 using Test
 
-LOGGING = get(ENV, "CI", "false") == "false"
-
 @testset verbose = true "Benchmarking static" begin
     filtered_static_scenarios = filter(static_scenarios(; include_batchified = false)) do scen
         DIT.function_place(scen) == :out && DIT.operator_place(scen) == :out
diff --git a/DifferentiationInterface/test/Back/ForwardDiff/test.jl b/DifferentiationInterface/test/Back/ForwardDiff/test.jl
index ef501aec1..df6050045 100644
--- a/DifferentiationInterface/test/Back/ForwardDiff/test.jl
+++ b/DifferentiationInterface/test/Back/ForwardDiff/test.jl
@@ -1,5 +1,4 @@
-using Pkg
-Pkg.add("ForwardDiff")
+include("../../testutils.jl")
 
 using ADTypes: ADTypes
 using ComponentArrays: ComponentArrays
@@ -14,8 +13,6 @@ using Test
 using ExplicitImports
 check_no_implicit_imports(DifferentiationInterface)
 
-LOGGING = get(ENV, "CI", "false") == "false"
-
 struct MyTag end
 
 backends = [
@@ -124,3 +121,5 @@ end
         prepare_jacobian(copyto!, similar(x), sparse_backend, x)
     ) == Vector{ForwardDiff.Dual{ForwardDiff.Tag{typeof(copyto!), Float64}, Float64, 1}}
 end;
+
+include("benchmark.jl")
diff --git a/DifferentiationInterface/test/Back/GTPSA/Project.toml b/DifferentiationInterface/test/Back/GTPSA/Project.toml
new file mode 100644
index 000000000..432414730
--- /dev/null
+++ b/DifferentiationInterface/test/Back/GTPSA/Project.toml
@@ -0,0 +1,9 @@
+[deps]
+ADTypes = "47edcb42-4c32-4615-8424-f2b9edc5f35b"
+DifferentiationInterface = "a0c0ee7d-e4b9-4e03-894e-1c5f64a51d63"
+DifferentiationInterfaceTest = "a82114a7-5aa3-49a8-9643-716bb13727a3"
+ExplicitImports = "7d51a73a-1435-4ff3-83d9-f097790105c7"
+GTPSA = "b27dd330-f138-47c5-815b-40db9dd9b6e8"
+SparseConnectivityTracer = "9f842d2f-2579-4b1d-911e-f412cf18a3f5"
+SparseMatrixColorings = "0a514795-09f3-496d-8182-132a7b665d35"
+Test = "8dfed614-e22c-5e08-85e1-65c5234f0b40"
diff --git a/DifferentiationInterface/test/Back/GTPSA/test.jl b/DifferentiationInterface/test/Back/GTPSA/test.jl
index 63d7e7ea5..6bdbcacbb 100644
--- a/DifferentiationInterface/test/Back/GTPSA/test.jl
+++ b/DifferentiationInterface/test/Back/GTPSA/test.jl
@@ -1,5 +1,4 @@
-using Pkg
-Pkg.add("GTPSA")
+include("../../testutils.jl")
 
 using DifferentiationInterface, DifferentiationInterfaceTest
 using GTPSA: GTPSA
@@ -8,8 +7,6 @@ using Test
 using ExplicitImports
 check_no_implicit_imports(DifferentiationInterface)
 
-LOGGING = get(ENV, "CI", "false") == "false"
-
 for backend in [AutoGTPSA()]
     @test check_available(backend)
     @test check_inplace(backend)
diff --git a/DifferentiationInterface/test/Back/Mooncake/Project.toml b/DifferentiationInterface/test/Back/Mooncake/Project.toml
new file mode 100644
index 000000000..39a878d7e
--- /dev/null
+++ b/DifferentiationInterface/test/Back/Mooncake/Project.toml
@@ -0,0 +1,9 @@
+[deps]
+ADTypes = "47edcb42-4c32-4615-8424-f2b9edc5f35b"
+DifferentiationInterface = "a0c0ee7d-e4b9-4e03-894e-1c5f64a51d63"
+DifferentiationInterfaceTest = "a82114a7-5aa3-49a8-9643-716bb13727a3"
+ExplicitImports = "7d51a73a-1435-4ff3-83d9-f097790105c7"
+Mooncake = "da2b9cff-9c12-43a0-ae48-6db2b0edb7d6"
+SparseConnectivityTracer = "9f842d2f-2579-4b1d-911e-f412cf18a3f5"
+SparseMatrixColorings = "0a514795-09f3-496d-8182-132a7b665d35"
+Test = "8dfed614-e22c-5e08-85e1-65c5234f0b40"
diff --git a/DifferentiationInterface/test/Back/Mooncake/test.jl b/DifferentiationInterface/test/Back/Mooncake/test.jl
index 3b61e3547..0f0aff4a9 100644
--- a/DifferentiationInterface/test/Back/Mooncake/test.jl
+++ b/DifferentiationInterface/test/Back/Mooncake/test.jl
@@ -1,5 +1,4 @@
-using Pkg
-Pkg.add("Mooncake")
+include("../../testutils.jl")
 
 using DifferentiationInterface, DifferentiationInterfaceTest
 using Mooncake: Mooncake
@@ -8,7 +7,6 @@ using Test
 using ExplicitImports
 check_no_implicit_imports(DifferentiationInterface)
 
-LOGGING = get(ENV, "CI", "false") == "false"
 
 backends = [
     AutoMooncake(; config = nothing),
diff --git a/DifferentiationInterface/test/Back/PolyesterForwardDiff/Project.toml b/DifferentiationInterface/test/Back/PolyesterForwardDiff/Project.toml
new file mode 100644
index 000000000..e487cb5f4
--- /dev/null
+++ b/DifferentiationInterface/test/Back/PolyesterForwardDiff/Project.toml
@@ -0,0 +1,10 @@
+[deps]
+ADTypes = "47edcb42-4c32-4615-8424-f2b9edc5f35b"
+DifferentiationInterface = "a0c0ee7d-e4b9-4e03-894e-1c5f64a51d63"
+DifferentiationInterfaceTest = "a82114a7-5aa3-49a8-9643-716bb13727a3"
+ExplicitImports = "7d51a73a-1435-4ff3-83d9-f097790105c7"
+ForwardDiff = "f6369f11-7733-5829-9624-2563aa707210"
+PolyesterForwardDiff = "98d1487c-24ca-40b6-b7ab-df2af84e126b"
+SparseConnectivityTracer = "9f842d2f-2579-4b1d-911e-f412cf18a3f5"
+SparseMatrixColorings = "0a514795-09f3-496d-8182-132a7b665d35"
+Test = "8dfed614-e22c-5e08-85e1-65c5234f0b40"
diff --git a/DifferentiationInterface/test/Back/PolyesterForwardDiff/test.jl b/DifferentiationInterface/test/Back/PolyesterForwardDiff/test.jl
index e1482731f..8ee877b98 100644
--- a/DifferentiationInterface/test/Back/PolyesterForwardDiff/test.jl
+++ b/DifferentiationInterface/test/Back/PolyesterForwardDiff/test.jl
@@ -1,5 +1,4 @@
-using Pkg
-Pkg.add(["ForwardDiff", "PolyesterForwardDiff"])
+include("../../testutils.jl")
 
 using DifferentiationInterface, DifferentiationInterfaceTest
 import DifferentiationInterface as DI
@@ -10,8 +9,6 @@ using Test
 using ExplicitImports
 check_no_implicit_imports(DifferentiationInterface)
 
-LOGGING = get(ENV, "CI", "false") == "false"
-
 struct MyTag end
 
 backends = [
diff --git a/DifferentiationInterface/test/Back/ReverseDiff/Project.toml b/DifferentiationInterface/test/Back/ReverseDiff/Project.toml
new file mode 100644
index 000000000..a8190995d
--- /dev/null
+++ b/DifferentiationInterface/test/Back/ReverseDiff/Project.toml
@@ -0,0 +1,11 @@
+[deps]
+ADTypes = "47edcb42-4c32-4615-8424-f2b9edc5f35b"
+DifferentiationInterface = "a0c0ee7d-e4b9-4e03-894e-1c5f64a51d63"
+DifferentiationInterfaceTest = "a82114a7-5aa3-49a8-9643-716bb13727a3"
+ExplicitImports = "7d51a73a-1435-4ff3-83d9-f097790105c7"
+ForwardDiff = "f6369f11-7733-5829-9624-2563aa707210"
+ReverseDiff = "37e2e3b7-166d-5795-8a7a-e32c996b4267"
+SparseConnectivityTracer = "9f842d2f-2579-4b1d-911e-f412cf18a3f5"
+SparseMatrixColorings = "0a514795-09f3-496d-8182-132a7b665d35"
+StaticArrays = "90137ffa-7385-5640-81b9-e52037218182"
+Test = "8dfed614-e22c-5e08-85e1-65c5234f0b40"
diff --git a/DifferentiationInterface/test/Back/ReverseDiff/test.jl b/DifferentiationInterface/test/Back/ReverseDiff/test.jl
index 2043c60f2..2450b9bbf 100644
--- a/DifferentiationInterface/test/Back/ReverseDiff/test.jl
+++ b/DifferentiationInterface/test/Back/ReverseDiff/test.jl
@@ -1,5 +1,4 @@
-using Pkg
-Pkg.add(["ForwardDiff", "ReverseDiff"])  # ForwardDiff already in ReverseDiff's deps
+include("../../testutils.jl")
 
 using DifferentiationInterface, DifferentiationInterfaceTest
 import DifferentiationInterface as DI
@@ -11,8 +10,6 @@ using Test
 using ExplicitImports
 check_no_implicit_imports(DifferentiationInterface)
 
-LOGGING = get(ENV, "CI", "false") == "false"
-
 backends = [AutoReverseDiff(; compile = false), AutoReverseDiff(; compile = true)]
 second_order_backends = [SecondOrder(AutoForwardDiff(), AutoReverseDiff())]
 
diff --git a/DifferentiationInterface/test/Back/SparsityDetector/Project.toml b/DifferentiationInterface/test/Back/SparsityDetector/Project.toml
new file mode 100644
index 000000000..ba2e0acc3
--- /dev/null
+++ b/DifferentiationInterface/test/Back/SparsityDetector/Project.toml
@@ -0,0 +1,13 @@
+[deps]
+ADTypes = "47edcb42-4c32-4615-8424-f2b9edc5f35b"
+DifferentiationInterface = "a0c0ee7d-e4b9-4e03-894e-1c5f64a51d63"
+DifferentiationInterfaceTest = "a82114a7-5aa3-49a8-9643-716bb13727a3"
+ExplicitImports = "7d51a73a-1435-4ff3-83d9-f097790105c7"
+ForwardDiff = "f6369f11-7733-5829-9624-2563aa707210"
+LinearAlgebra = "37e2e46d-f89d-539d-b4ee-838fcccc9c8e"
+ReverseDiff = "37e2e3b7-166d-5795-8a7a-e32c996b4267"
+SparseArrays = "2f01184e-e22b-5df5-ae63-d93ebab69eaf"
+SparseConnectivityTracer = "9f842d2f-2579-4b1d-911e-f412cf18a3f5"
+SparseMatrixColorings = "0a514795-09f3-496d-8182-132a7b665d35"
+StableRNGs = "860ef19b-820b-49d6-a774-d7a799459cd3"
+Test = "8dfed614-e22c-5e08-85e1-65c5234f0b40"
diff --git a/DifferentiationInterface/test/Back/SparsityDetector/test.jl b/DifferentiationInterface/test/Back/SparsityDetector/test.jl
index f1de5c11b..cb77d0b44 100644
--- a/DifferentiationInterface/test/Back/SparsityDetector/test.jl
+++ b/DifferentiationInterface/test/Back/SparsityDetector/test.jl
@@ -1,5 +1,4 @@
-using Pkg
-Pkg.add(["ForwardDiff", "ReverseDiff"])
+include("../../testutils.jl")
 
 using ADTypes: jacobian_sparsity, hessian_sparsity
 using DifferentiationInterface
diff --git a/DifferentiationInterface/test/Back/Symbolics/Project.toml b/DifferentiationInterface/test/Back/Symbolics/Project.toml
new file mode 100644
index 000000000..2729711e1
--- /dev/null
+++ b/DifferentiationInterface/test/Back/Symbolics/Project.toml
@@ -0,0 +1,10 @@
+[deps]
+ADTypes = "47edcb42-4c32-4615-8424-f2b9edc5f35b"
+DifferentiationInterface = "a0c0ee7d-e4b9-4e03-894e-1c5f64a51d63"
+DifferentiationInterfaceTest = "a82114a7-5aa3-49a8-9643-716bb13727a3"
+ExplicitImports = "7d51a73a-1435-4ff3-83d9-f097790105c7"
+LinearAlgebra = "37e2e46d-f89d-539d-b4ee-838fcccc9c8e"
+SparseConnectivityTracer = "9f842d2f-2579-4b1d-911e-f412cf18a3f5"
+SparseMatrixColorings = "0a514795-09f3-496d-8182-132a7b665d35"
+Symbolics = "0c5d862f-8b57-4792-8d23-62f2024744c7"
+Test = "8dfed614-e22c-5e08-85e1-65c5234f0b40"
diff --git a/DifferentiationInterface/test/Back/Symbolics/symbolics.jl b/DifferentiationInterface/test/Back/Symbolics/test.jl
similarity index 94%
rename from DifferentiationInterface/test/Back/Symbolics/symbolics.jl
rename to DifferentiationInterface/test/Back/Symbolics/test.jl
index 5fe04d8c9..076d113e8 100644
--- a/DifferentiationInterface/test/Back/Symbolics/symbolics.jl
+++ b/DifferentiationInterface/test/Back/Symbolics/test.jl
@@ -1,5 +1,4 @@
-using Pkg
-Pkg.add("Symbolics")
+include("../../testutils.jl")
 
 using DifferentiationInterface, DifferentiationInterfaceTest
 using SparseMatrixColorings
@@ -10,8 +9,6 @@ using Test
 using ExplicitImports
 check_no_implicit_imports(DifferentiationInterface)
 
-LOGGING = get(ENV, "CI", "false") == "false"
-
 for backend in [AutoSymbolics(), AutoSparse(AutoSymbolics())]
     @test check_available(backend)
     @test check_inplace(backend)
diff --git a/DifferentiationInterface/test/Back/Tracker/Project.toml b/DifferentiationInterface/test/Back/Tracker/Project.toml
new file mode 100644
index 000000000..370fa405a
--- /dev/null
+++ b/DifferentiationInterface/test/Back/Tracker/Project.toml
@@ -0,0 +1,9 @@
+[deps]
+ADTypes = "47edcb42-4c32-4615-8424-f2b9edc5f35b"
+DifferentiationInterface = "a0c0ee7d-e4b9-4e03-894e-1c5f64a51d63"
+DifferentiationInterfaceTest = "a82114a7-5aa3-49a8-9643-716bb13727a3"
+ExplicitImports = "7d51a73a-1435-4ff3-83d9-f097790105c7"
+SparseConnectivityTracer = "9f842d2f-2579-4b1d-911e-f412cf18a3f5"
+SparseMatrixColorings = "0a514795-09f3-496d-8182-132a7b665d35"
+Test = "8dfed614-e22c-5e08-85e1-65c5234f0b40"
+Tracker = "9f7883ad-71c0-57eb-9f7f-b5c9e6d3789c"
diff --git a/DifferentiationInterface/test/Back/Tracker/test.jl b/DifferentiationInterface/test/Back/Tracker/test.jl
index fe54c6aaf..a6fcfb671 100644
--- a/DifferentiationInterface/test/Back/Tracker/test.jl
+++ b/DifferentiationInterface/test/Back/Tracker/test.jl
@@ -1,5 +1,4 @@
-using Pkg
-Pkg.add("Tracker")
+include("../../testutils.jl")
 
 using DifferentiationInterface, DifferentiationInterfaceTest
 using Tracker: Tracker
@@ -8,8 +7,6 @@ using Test
 using ExplicitImports
 check_no_implicit_imports(DifferentiationInterface)
 
-LOGGING = get(ENV, "CI", "false") == "false"
-
 for backend in [AutoTracker()]
     @test check_available(backend)
     @test !check_inplace(backend)
diff --git a/DifferentiationInterface/test/Back/Zygote/Project.toml b/DifferentiationInterface/test/Back/Zygote/Project.toml
new file mode 100644
index 000000000..d254f7d5f
--- /dev/null
+++ b/DifferentiationInterface/test/Back/Zygote/Project.toml
@@ -0,0 +1,13 @@
+[deps]
+ADTypes = "47edcb42-4c32-4615-8424-f2b9edc5f35b"
+ComponentArrays = "b0b7db55-cfe3-40fc-9ded-d10e2dbeff66"
+DifferentiationInterface = "a0c0ee7d-e4b9-4e03-894e-1c5f64a51d63"
+DifferentiationInterfaceTest = "a82114a7-5aa3-49a8-9643-716bb13727a3"
+ExplicitImports = "7d51a73a-1435-4ff3-83d9-f097790105c7"
+ForwardDiff = "f6369f11-7733-5829-9624-2563aa707210"
+JLArrays = "27aeb0d3-9eb9-45fb-866b-73c2ecf80fcb"
+SparseConnectivityTracer = "9f842d2f-2579-4b1d-911e-f412cf18a3f5"
+SparseMatrixColorings = "0a514795-09f3-496d-8182-132a7b665d35"
+StaticArrays = "90137ffa-7385-5640-81b9-e52037218182"
+Test = "8dfed614-e22c-5e08-85e1-65c5234f0b40"
+Zygote = "e88e6eb3-aa80-5325-afca-941959d7151f"
diff --git a/DifferentiationInterface/test/Back/Zygote/test.jl b/DifferentiationInterface/test/Back/Zygote/test.jl
index f9dc8c78f..ceeeedbc5 100644
--- a/DifferentiationInterface/test/Back/Zygote/test.jl
+++ b/DifferentiationInterface/test/Back/Zygote/test.jl
@@ -1,5 +1,4 @@
-using Pkg
-Pkg.add(["ForwardDiff", "Zygote"])
+include("../../testutils.jl")
 
 using ComponentArrays: ComponentArrays
 using DifferentiationInterface, DifferentiationInterfaceTest
@@ -12,8 +11,6 @@ using Zygote: Zygote
 using ExplicitImports
 check_no_implicit_imports(DifferentiationInterface)
 
-LOGGING = get(ENV, "CI", "false") == "false"
-
 backends = [AutoZygote()]
 second_order_backends = [SecondOrder(AutoForwardDiff(), AutoZygote())]
 
diff --git a/DifferentiationInterface/test/Back/run_backend.jl b/DifferentiationInterface/test/Back/run_backend.jl
new file mode 100644
index 000000000..637feb4c4
--- /dev/null
+++ b/DifferentiationInterface/test/Back/run_backend.jl
@@ -0,0 +1,5 @@
+using Test
+group = ENV["JULIA_DI_TEST_GROUP"]
+@testset "$group" begin
+    include(joinpath(@__DIR__, group, "test.jl"))
+end
diff --git a/DifferentiationInterface/test/Core/SimpleFiniteDiff/test.jl b/DifferentiationInterface/test/Core/SimpleFiniteDiff/test.jl
index 1bd40bfa6..fe739284e 100644
--- a/DifferentiationInterface/test/Core/SimpleFiniteDiff/test.jl
+++ b/DifferentiationInterface/test/Core/SimpleFiniteDiff/test.jl
@@ -8,8 +8,6 @@ using SparseMatrixColorings
 using JLArrays, StaticArrays
 using Test
 
-LOGGING = get(ENV, "CI", "false") == "false"
-
 backends = [ #
     AutoSimpleFiniteDiff(; chunksize = 5),
     AutoForwardFromPrimitive(AutoSimpleFiniteDiff(; chunksize = 4)),
diff --git a/DifferentiationInterface/test/Core/ZeroBackends/test.jl b/DifferentiationInterface/test/Core/ZeroBackends/test.jl
index 6b84e56a4..24aeb0d2c 100644
--- a/DifferentiationInterface/test/Core/ZeroBackends/test.jl
+++ b/DifferentiationInterface/test/Core/ZeroBackends/test.jl
@@ -8,7 +8,6 @@ using SparseMatrixColorings
 using StaticArrays: StaticArrays
 using Test
 
-LOGGING = get(ENV, "CI", "false") == "false"
 
 zero_backends = [AutoZeroForward(), AutoZeroReverse()]
 
diff --git a/DifferentiationInterface/test/runtests.jl b/DifferentiationInterface/test/runtests.jl
index 66159c3d9..cd01c7f36 100644
--- a/DifferentiationInterface/test/runtests.jl
+++ b/DifferentiationInterface/test/runtests.jl
@@ -1,47 +1,25 @@
 using DifferentiationInterface
-using Pkg
 using Test
 
-@static if VERSION < v"1.11"
-    DIT_PATH = joinpath(@__DIR__, "..", "..", "DifferentiationInterfaceTest")
-    if isdir(DIT_PATH)
-        Pkg.develop(; path = DIT_PATH)
-    else
-        Pkg.add("DifferentiationInterfaceTest")
-    end
-end
-
 include("testutils.jl")
 
 ## Main tests
 
-@time @testset verbose = true "DifferentiationInterface.jl" begin
-    if haskey(ENV, "JULIA_DI_TEST_GROUP")
-        category, folder = split(ENV["JULIA_DI_TEST_GROUP"], '/')
-        @testset verbose = true "$category" begin
-            @testset verbose = true "$folder" begin
-                @testset verbose = true "$file" for file in readdir(
-                        joinpath(@__DIR__, category, folder)
-                    )
-                    endswith(file, ".jl") || continue
-                    @info "Testing $category/$folder/$file"
-                    include(joinpath(@__DIR__, category, folder, file))
-                    yield()
-                end
-            end
-        end
-    else
-        category = "Core"
-        @testset verbose = true for folder in readdir(joinpath(@__DIR__, category))
-            isdir(joinpath(@__DIR__, category, folder)) || continue
-            @testset verbose = true "$file" for file in readdir(
-                    joinpath(@__DIR__, category, folder)
-                )
-                endswith(file, ".jl") || continue
-                @info "Testing $category/$folder/$file"
-                include(joinpath(@__DIR__, category, folder, file))
-                yield()
-            end
+if haskey(ENV, "JULIA_DI_TEST_GROUP")
+    folders = [ENV["JULIA_DI_TEST_GROUP"]]
+else
+    folders = ["Internals", "SimpleFiniteDiff", "ZeroBackends"]
+end
+
+@time @testset verbose = true "DifferentiationInterface.jl (Core)" begin
+    @testset verbose = true "$folder" for folder in folders
+        @testset verbose = true "$file" for file in readdir(
+                joinpath(@__DIR__, "Core", folder)
+            )
+            endswith(file, ".jl") || continue
+            @info "Testing $folder/$file"
+            include(joinpath(@__DIR__, "Core", folder, file))
+            yield()
         end
     end
 end;
diff --git a/DifferentiationInterface/test/testutils.jl b/DifferentiationInterface/test/testutils.jl
index 5bb8bd3a8..7329f4abf 100644
--- a/DifferentiationInterface/test/testutils.jl
+++ b/DifferentiationInterface/test/testutils.jl
@@ -1,7 +1,19 @@
+using Pkg
+
+@static if VERSION < v"1.11"
+    DIT_PATH = joinpath(@__DIR__, "..", "..", "DifferentiationInterfaceTest")
+    if isdir(DIT_PATH)
+        Pkg.develop(; path = DIT_PATH)
+    else
+        Pkg.add("DifferentiationInterfaceTest")
+    end
+end
+
 using ADTypes
 using DifferentiationInterfaceTest
 using SparseConnectivityTracer
 using SparseMatrixColorings
+using Test
 
 using DifferentiationInterfaceTest:
     default_scenarios,
@@ -22,3 +34,5 @@ function MyAutoSparse(backend::AbstractADType)
 end
 
 safetypestab(symb) = VERSION < v"1.12-" ? symb : :none  # TODO: remove
+
+LOGGING = get(ENV, "CI", "false") == "false"
diff --git a/DifferentiationInterfaceTest/test/runtests.jl b/DifferentiationInterfaceTest/test/runtests.jl
index ee96ca118..4691fee52 100644
--- a/DifferentiationInterfaceTest/test/runtests.jl
+++ b/DifferentiationInterfaceTest/test/runtests.jl
@@ -19,6 +19,8 @@ GROUP = get(ENV, "JULIA_DIT_TEST_GROUP", "All")
 
 safetypestab(symb) = VERSION < v"1.12-" ? symb : :none  # TODO: remove
 
+LOGGING = get(ENV, "CI", "false") == "false"
+
 ## Main tests
 
 @time @testset verbose = true "DifferentiationInterfaceTest.jl" begin
diff --git a/DifferentiationInterfaceTest/test/standard.jl b/DifferentiationInterfaceTest/test/standard.jl
index a3240e42e..1d26a0c75 100644
--- a/DifferentiationInterfaceTest/test/standard.jl
+++ b/DifferentiationInterfaceTest/test/standard.jl
@@ -7,8 +7,6 @@ using SparseConnectivityTracer
 using SparseMatrixColorings
 using Random
 
-LOGGING = get(ENV, "CI", "false") == "false"
-
 ## Dense
 
 test_differentiation(
diff --git a/DifferentiationInterfaceTest/test/weird.jl b/DifferentiationInterfaceTest/test/weird.jl
index f56831690..6f76c2dc0 100644
--- a/DifferentiationInterfaceTest/test/weird.jl
+++ b/DifferentiationInterfaceTest/test/weird.jl
@@ -13,8 +13,6 @@ using SparseMatrixColorings
 using StaticArrays: StaticArrays
 using Zygote: Zygote
 
-LOGGING = get(ENV, "CI", "false") == "false"
-
 ## Generate all scenarios
 
 gpu_scenarios(;
diff --git a/DifferentiationInterfaceTest/test/zero_backends.jl b/DifferentiationInterfaceTest/test/zero_backends.jl
index 8796d524f..b4a0f1bd1 100644
--- a/DifferentiationInterfaceTest/test/zero_backends.jl
+++ b/DifferentiationInterfaceTest/test/zero_backends.jl
@@ -5,8 +5,6 @@ using DifferentiationInterfaceTest
 using DifferentiationInterfaceTest: allocfree_scenarios, no_matrices
 using Test
 
-LOGGING = get(ENV, "CI", "false") == "false"
-
 ## Type stability
 
 test_differentiation(