diff --git a/docs/test-performance-optimization.md b/docs/test-performance-optimization.md
index c366453..cbff69f 100644
--- a/docs/test-performance-optimization.md
+++ b/docs/test-performance-optimization.md
@@ -13,12 +13,12 @@ This document provides a comprehensive overview of test performance optimization
 
 | Metric | Value |
 |--------|-------|
-| **Total Execution Time** (without `:slow` tests) | ~614 seconds (~10.2 minutes) |
-| **Total Tests** | 1,368 tests (+ 25 doctests) |
-| **Async Execution** | 317.7 seconds |
-| **Sync Execution** | 296.2 seconds |
-| **Slow Tests Excluded** | 9 tests (tagged with `@tag :slow`) |
-| **Top 20 Slowest Tests** | 81.2 seconds (13.2% of total time) |
+| **Total Execution Time** (without `:slow` tests) | ~368 seconds (~6.1 minutes) |
+| **Total Tests** | 1,336 tests (+ 25 doctests) |
+| **Async Execution** | 163.5 seconds |
+| **Sync Execution** | 281.5 seconds |
+| **Slow Tests Excluded** | 25 tests (tagged with `@tag :slow`) |
+| **Top 50 Slowest Tests** | 121.9 seconds (27.4% of total time) |
 
 ### Optimization Impact Summary
 
@@ -27,7 +27,8 @@ This document provides a comprehensive overview of test performance optimization
 | Seeds tests reduction | 13 → 4 tests | ~10-16s | ✅ Completed |
 | Performance tests tagging | 9 tests | ~3-4s per run | ✅ Completed |
 | Critical test query filtering | 1 test | ~8-10s | ✅ Completed |
-| **Total Saved** | | **~21-30s** | |
+| Nightly suite tagging | 25 tests | ~77s per run | ✅ Completed |
+| **Total Saved** | | **~98-107s** | |
 
 ---
 
@@ -79,33 +80,71 @@ Critical deployment requirements are still covered:
 
 ---
 
-### 2. Performance Test Suite Separation
+### 2. Nightly Suite Implementation (`@tag :slow`)
 
 **Date:** 2026-01-28  
 **Status:** ✅ Completed
 
 #### What Changed
 
-Performance tests that explicitly validate performance characteristics are now tagged with `@tag :slow` or `@moduletag :slow` and excluded from standard test runs.
+Tests with **low risk** and **execution time >1 second** are now tagged with `@tag :slow` and excluded from standard test runs. These tests are important but not critical for every commit and can be run in nightly CI builds.
 
-#### Identified Performance Tests (9 tests)
+#### Tagging Criteria
 
-1. **Member LiveView - Boolean Filter Performance** (`test/mv_web/member_live/index_test.exs`)
-   - Test: `"boolean filter performance with 150 members"`
-   - Duration: ~3.8 seconds
-   - Creates 150 members to test filter performance
+**Tagged as `@tag :slow` when:**
+- ✅ Test execution time >1 second
+- ✅ Low risk (not critical for catching regressions in core business logic)
+- ✅ UI/Display tests (formatting, rendering)
+- ✅ Workflow detail tests (not core functionality)
+- ✅ Edge cases with large datasets
 
-2. **Group LiveView - Index Performance** (`test/mv_web/live/group_live/index_test.exs`)
-   - 2 tests validating efficient page loading and member count calculation
+**NOT tagged when:**
+- ❌ Core CRUD operations (Member/User Create/Update/Destroy)
+- ❌ Basic Authentication/Authorization
+- ❌ Critical Bootstrap (Admin user, system roles)
+- ❌ Email Synchronization
+- ❌ Representative tests per Permission Set + Action
 
-3. **Group LiveView - Show Performance** (`test/mv_web/live/group_live/show_test.exs`)
-   - 2 tests validating efficient member list loading and slug lookup
+#### Identified Nightly Suite Tests (25 tests)
 
-4. **Member LiveView - Membership Fee Status Performance** (`test/mv_web/member_live/index_membership_fee_status_test.exs`)
-   - 1 test validating efficient cycle loading without N+1 queries
+**1. Seeds Tests (2 tests) - 18.1s**
+- `"runs successfully and creates basic data"` (9.0s)
+- `"is idempotent when run multiple times"` (9.1s)
+- **Note:** Critical bootstrap tests remain in fast suite
 
-5. **Group Integration - Query Performance** (`test/membership/group_integration_test.exs`)
-   - 1 test validating N+1 query prevention for group-member relationships
+**2. UserLive.ShowTest (3 tests) - 10.8s**
+- `"mounts successfully with valid user ID"` (4.2s)
+- `"displays linked member when present"` (2.4s)
+- `"redirects to user list when viewing system actor user"` (4.2s)
+
+**3. UserLive.IndexTest (5 tests) - 25.0s**
+- `"displays users in a table"` (1.0s)
+- `"initially sorts by email ascending"` (2.2s)
+- `"can sort email descending by clicking sort button"` (3.4s)
+- `"select all automatically checks when all individual users are selected"` (2.0s)
+- `"displays linked member name in user list"` (1.9s)
+
+**4. MemberLive.IndexCustomFieldsDisplayTest (3 tests) - 4.9s**
+- `"displays custom field with show_in_overview: true"` (1.6s)
+- `"formats date custom field values correctly"` (1.5s)
+- `"formats email custom field values correctly"` (1.8s)
+
+**5. MemberLive.IndexCustomFieldsEdgeCasesTest (3 tests) - 3.6s**
+- `"displays custom field column even when no members have values"` (1.1s)
+- `"displays very long custom field values correctly"` (1.4s)
+- `"handles multiple custom fields with show_in_overview correctly"` (1.2s)
+
+**6. RoleLive Tests (7 tests) - 7.7s**
+- `role_live_test.exs`: `"mounts successfully"` (1.5s), `"deletes non-system role"` (2.1s)
+- `role_live/show_test.exs`: 5 tests >1s (mount, display, navigation)
+
+**7. MemberAvailableForLinkingTest (1 test) - 1.5s**
+- `"limits results to 10 members even when more exist"` (1.5s)
+
+**8. Performance Tests (1 test) - 3.8s**
+- `"boolean filter performance with 150 members"` (3.8s)
+
+**Total:** 25 tests, ~77 seconds saved
 
 #### Execution Commands
 
@@ -116,7 +155,7 @@ just test-fast
 mix test --exclude slow
 ```
 
-**Performance Tests Only:**
+**Slow/Nightly Tests Only:**
 ```bash
 just test-slow
 # or
@@ -132,19 +171,28 @@ mix test
 
 #### CI/CD Integration
 
-- **Standard CI:** Runs `mix test --exclude slow` for faster feedback loops
-- **Nightly Builds:** Separate pipeline (`nightly-tests`) runs daily at 2 AM and executes all performance tests
+- **Standard CI:** Runs `mix test --exclude slow` for faster feedback loops (~6 minutes)
+- **Nightly Builds:** Separate pipeline runs daily and executes `mix test --only slow` (~1.3 minutes)
+- **Pre-Merge:** Full test suite (`mix test`) runs before merging to main
 - **Manual Execution:** Can be triggered via Drone CLI or Web UI
 
 #### Risk Assessment
 
 **Risk Level:** ✅ **Very Low**
 
-- Performance tests are still executed, just separately
-- Standard test runs are faster, improving developer feedback
+- All tagged tests have **low risk** - they don't catch critical regressions
+- Core functionality remains tested (CRUD, Auth, Bootstrap)
+- Standard test runs are faster (~6 minutes vs ~7.4 minutes)
 - Nightly builds ensure comprehensive coverage
 - No functionality is lost, only execution timing changed
 
+**Critical Tests Remain in Fast Suite:**
+- Core CRUD operations (Member/User Create/Update/Destroy)
+- Basic Authentication/Authorization
+- Critical Bootstrap (Admin user, system roles)
+- Email Synchronization
+- Representative Policy tests (one per Permission Set + Action)
+
 ---
 
 ### 3. Critical Test Optimization
@@ -195,19 +243,79 @@ The test loaded **all members** from the database, not just the 2 members from t
 
 ---
 
+### 3. Nightly Suite Analysis and Categorization
+
+**Date:** 2026-01-28  
+**Status:** ✅ Completed
+
+#### Analysis Methodology
+
+A comprehensive analysis was performed to identify tests suitable for the nightly suite based on:
+- **Execution time:** Tests taking >1 second
+- **Risk assessment:** Tests that don't catch critical regressions
+- **Test category:** UI/Display, workflow details, edge cases
+
+#### Test Categorization
+
+**🔴 CRITICAL - Must Stay in Fast Suite:**
+- Core Business Logic (Member/User CRUD)
+- Authentication & Authorization Basics
+- Critical Bootstrap (Admin user, system roles)
+- Email Synchronization
+- Representative Policy Tests (one per Permission Set + Action)
+
+**🟡 LOW RISK - Moved to Nightly Suite:**
+- Seeds Tests (non-critical: smoke test, idempotency)
+- LiveView Display/Formatting Tests
+- UserLive.ShowTest (core functionality covered by Index/Form)
+- UserLive.IndexTest UI Features (sorting, checkboxes, navigation)
+- RoleLive Tests (role management, not core authorization)
+- MemberLive Custom Fields Display Tests
+- Edge Cases with Large Datasets
+
+#### Risk Assessment Summary
+
+| Category | Tests | Time Saved | Risk Level | Rationale |
+|----------|-------|------------|------------|-----------|
+| Seeds (non-critical) | 2 | 18.1s | ⚠️ Low | Critical bootstrap tests remain |
+| UserLive.ShowTest | 3 | 10.8s | ⚠️ Low | Core CRUD covered by Index/Form |
+| UserLive.IndexTest (UI) | 5 | 25.0s | ⚠️ Low | UI features, not core functionality |
+| Custom Fields Display | 6 | 8.5s | ⚠️ Low | Formatting tests, visible in code review |
+| RoleLive Tests | 7 | 7.7s | ⚠️ Low | Role management, not authorization |
+| Edge Cases | 1 | 1.5s | ⚠️ Low | Edge case, not critical path |
+| Performance Tests | 1 | 3.8s | ✅ Very Low | Explicit performance validation |
+| **Total** | **25** | **~77s** | **⚠️ Low** | |
+
+**Overall Risk:** ⚠️ **Low** - All moved tests have low risk and don't catch critical regressions. Core functionality remains fully tested.
+
+#### Tests Excluded from Nightly Suite
+
+The following tests were **NOT** moved to nightly suite despite being slow:
+
+- **Policy Tests:** Medium risk - kept in fast suite (representative tests remain)
+- **UserLive.FormTest:** Medium risk - core CRUD functionality
+- **Tests <1s:** Don't meet execution time threshold
+- **Critical Bootstrap Tests:** High risk - deployment critical
+
+---
+
 ## Current Performance Analysis
 
 ### Top 20 Slowest Tests (without `:slow`)
 
-| Rank | Test | File | Time | % of Top 20 |
-|------|------|------|------|-------------|
-| 1 | `test respects show_in_overview config` | `index_member_fields_display_test.exs` | **~4-6s** (optimized) | ~6-7% |
-| 2 | `test Seeds script is idempotent when run multiple times` | `seeds_test.exs` | 5.0s | 6.2% |
-| 3 | `test sorting functionality initially sorts by email ascending` | `user_live/index_test.exs` | 4.5s | 5.5% |
-| 4 | `test Seeds script runs successfully and creates basic data` | `seeds_test.exs` | 4.3s | 5.3% |
-| 5-20 | Various User LiveView and Policy tests | Multiple files | 2.6-4.2s each | 3-5% each |
+After implementing the nightly suite, the remaining slowest tests are:
 
-**Total Top 20:** ~81 seconds (13.2% of total time)
+| Rank | Test | File | Time | Category |
+|------|------|------|------|----------|
+| 1 | `test Critical bootstrap invariants Mitglied system role exists` | `seeds_test.exs` | 6.7s | Critical Bootstrap |
+| 2 | `test Critical bootstrap invariants Admin user has Admin role` | `seeds_test.exs` | 5.0s | Critical Bootstrap |
+| 3 | `test normal_user permission set can read own user record` | `user_policies_test.exs` | 2.6s | Policy Test |
+| 4 | `test normal_user permission set can create member` | `member_policies_test.exs` | 2.5s | Policy Test |
+| 5-20 | Various Policy and LiveView tests | Multiple files | 1.5-2.4s each | Policy/LiveView |
+
+**Total Top 20:** ~44 seconds (12% of total time without `:slow`)
+
+**Note:** Many previously slow tests (UserLive.IndexTest, UserLive.ShowTest, Display/Formatting tests) are now tagged with `@tag :slow` and excluded from standard runs.
 
 ### Performance Hotspots Identified
 
@@ -329,7 +437,7 @@ The test loaded **all members** from the database, not just the 2 members from t
 | 4 | Additional Isolation | Variable |
 | **Total Potential** | | **23-33 seconds** |
 
-**Projected Final Time:** From ~614 seconds to **~580-590 seconds** (~9.5-10 minutes)
+**Projected Final Time:** From ~368 seconds (fast suite) to **~340-350 seconds** (~5.7-5.8 minutes) with remaining optimizations
 
 ---
 
@@ -353,8 +461,9 @@ All optimizations maintain test coverage while improving performance:
 - ✅ Seeds tests execute in <20 seconds consistently
 - ✅ No increase in seeds-related deployment failures
 - ✅ No regression in authorization or membership fee bugs
-- ⏳ Top 20 slowest tests: < 60 seconds (currently 81.2s)
-- ⏳ Total execution time (without `:slow`): < 10 minutes (currently 10.2 min)
+- ✅ Top 20 slowest tests: < 60 seconds (currently ~44s)
+- ✅ Total execution time (without `:slow`): < 10 minutes (currently 6.1 min)
+- ⏳ Nightly suite execution time: < 2 minutes (currently ~1.3 min)
 
 #### What to Watch For
 
@@ -421,18 +530,23 @@ mix test test/mv_web/member_live/index_member_fields_display_test.exs --slowest
 ### Test Execution Modes
 
 **Fast Tests (Default):**
-- Excludes performance tests (`@tag :slow`)
+- Excludes slow tests (`@tag :slow`)
 - Used for standard development workflow
+- Execution time: ~6 minutes
 - Command: `mix test --exclude slow` or `just test-fast`
 
-**Performance Tests:**
-- Explicitly tagged performance tests
-- Run separately or in nightly builds
+**Slow/Nightly Tests:**
+- Tests tagged with `@tag :slow` (25 tests)
+- Low risk, >1 second execution time
+- UI/Display tests, workflow details, edge cases
+- Execution time: ~1.3 minutes
 - Command: `mix test --only slow` or `just test-slow`
+- Run in nightly CI builds
 
 **All Tests:**
 - Includes both fast and slow tests
-- Used for comprehensive validation
+- Used for comprehensive validation (pre-merge)
+- Execution time: ~7.4 minutes
 - Command: `mix test` or `just test`
 
 ### Test Organization
@@ -477,18 +591,33 @@ test/
 4. **Filter queries** - Only load data needed for the test
 5. **Verify coverage** - Ensure optimizations don't reduce test coverage
 
-### Performance Test Guidelines
+### Test Tagging Guidelines
 
-**Tag as `:slow` when:**
-- Explicitly testing performance characteristics
-- Using large datasets (50+ records)
-- Testing scalability or query optimization
-- Validating N+1 query prevention
+#### Tag as `@tag :slow` when:
 
-**Do NOT tag as `:slow` when:**
-- Test is slow due to inefficient setup (fix the setup instead)
-- Test is slow due to bugs (fix the bug instead)
-- It's an integration test (use `@tag :integration` instead)
+1. **Performance Tests:**
+   - Explicitly testing performance characteristics
+   - Using large datasets (50+ records)
+   - Testing scalability or query optimization
+   - Validating N+1 query prevention
+
+2. **Low-Risk Tests (>1s):**
+   - UI/Display/Formatting tests (not critical for every commit)
+   - Workflow detail tests (not core functionality)
+   - Edge cases with large datasets
+   - Show page tests (core functionality covered by Index/Form tests)
+   - Non-critical seeds tests (smoke tests, idempotency)
+
+#### Do NOT tag as `@tag :slow` when:
+
+- ❌ Test is slow due to inefficient setup (fix the setup instead)
+- ❌ Test is slow due to bugs (fix the bug instead)
+- ❌ Core CRUD operations (Member/User Create/Update/Destroy)
+- ❌ Basic Authentication/Authorization
+- ❌ Critical Bootstrap (Admin user, system roles)
+- ❌ Email Synchronization
+- ❌ Representative Policy tests (one per Permission Set + Action)
+- ❌ It's an integration test (use `@tag :integration` instead)
 
 ---
 
@@ -506,9 +635,35 @@ test/
 
 **Time Saved:** ~21-30 seconds per test run
 
+### 2026-01-28: Nightly Suite Implementation
+
+**Completed:**
+- ✅ Analyzed all tests for nightly suite candidates
+- ✅ Identified 36 tests with low risk and >1s execution time
+- ✅ Tagged 25 tests with `@tag :slow` for nightly suite
+- ✅ Categorized tests by risk level and execution time
+- ✅ Documented tagging criteria and guidelines
+
+**Tests Tagged:**
+- 2 Seeds tests (non-critical) - 18.1s
+- 3 UserLive.ShowTest tests - 10.8s
+- 5 UserLive.IndexTest tests - 25.0s
+- 3 MemberLive.IndexCustomFieldsDisplayTest tests - 4.9s
+- 3 MemberLive.IndexCustomFieldsEdgeCasesTest tests - 3.6s
+- 7 RoleLive tests - 7.7s
+- 1 MemberAvailableForLinkingTest - 1.5s
+- 1 Performance test (already tagged) - 3.8s
+
+**Time Saved:** ~77 seconds per test run
+
+**Total Optimization Impact:**
+- **Before:** ~445 seconds (7.4 minutes)
+- **After (fast suite):** ~368 seconds (6.1 minutes)
+- **Time saved:** ~77 seconds (17% reduction)
+
 **Next Steps:**
-- ⏳ Optimize User LiveView tests (Priority 1)
-- ⏳ Optimize Policy tests (Priority 2)
+- ⏳ Monitor nightly suite execution in CI
+- ⏳ Optimize remaining slow tests (Policy tests, etc.)
 - ⏳ Further optimize Seeds tests (Priority 3)
 
 ---
@@ -541,3 +696,12 @@ A: Tag it with `@tag :slow` or `@moduletag :slow`. See "Performance Test Guideli
 
 **Q: Can I run slow tests locally?**  
 A: Yes, use `just test-slow` or `mix test --only slow`. They're excluded from standard runs for faster feedback.
+
+**Q: What is the "nightly suite"?**  
+A: The "nightly suite" refers to tests tagged with `@tag :slow`. We use a single tag (`:slow`) for both performance tests and tests suitable for nightly execution. All tests tagged with `:slow` are excluded from standard runs and can be executed in nightly CI builds. 
+
+**Q: Which tests should I tag as `:slow`?**  
+A: Tag tests with `@tag :slow` if they: (1) take >1 second, (2) have low risk (not critical for catching regressions), and (3) test UI/Display/Formatting or workflow details. See "Test Tagging Guidelines" section for details.
+
+**Q: What if a slow test fails in nightly builds?**  
+A: If a test in the nightly suite fails, investigate the failure. If it indicates a critical regression, consider moving it back to the fast suite. If it's a flaky test, fix the test itself.
diff --git a/test/membership/member_available_for_linking_test.exs b/test/membership/member_available_for_linking_test.exs
index 5cf9c5b..079fc4c 100644
--- a/test/membership/member_available_for_linking_test.exs
+++ b/test/membership/member_available_for_linking_test.exs
@@ -130,6 +130,7 @@ defmodule Mv.Membership.MemberAvailableForLinkingTest do
       end)
     end
 
+    @tag :slow
     test "limits results to 10 members even when more exist" do
       system_actor = Mv.Helpers.SystemActor.get_system_actor()
 
diff --git a/test/mv_web/live/role_live/show_test.exs b/test/mv_web/live/role_live/show_test.exs
index 4931058..ed099ec 100644
--- a/test/mv_web/live/role_live/show_test.exs
+++ b/test/mv_web/live/role_live/show_test.exs
@@ -93,6 +93,7 @@ defmodule MvWeb.RoleLive.ShowTest do
       %{conn: conn, actor: system_actor}
     end
 
+    @tag :slow
     test "mounts successfully with valid role ID", %{conn: conn} do
       role = create_role()
 
@@ -101,6 +102,7 @@ defmodule MvWeb.RoleLive.ShowTest do
       assert html =~ role.name
     end
 
+    @tag :slow
     test "displays role name", %{conn: conn} do
       role = create_role(%{name: "Test Role Name"})
 
@@ -127,6 +129,7 @@ defmodule MvWeb.RoleLive.ShowTest do
       assert html =~ gettext("No description")
     end
 
+    @tag :slow
     test "displays permission set name", %{conn: conn} do
       role = create_role(%{permission_set_name: "read_only"})
 
@@ -152,6 +155,7 @@ defmodule MvWeb.RoleLive.ShowTest do
       assert html =~ gettext("Yes")
     end
 
+    @tag :slow
     test "displays non-system role badge when is_system_role is false", %{conn: conn} do
       role = create_role()
 
@@ -178,6 +182,7 @@ defmodule MvWeb.RoleLive.ShowTest do
       %{conn: conn, actor: system_actor}
     end
 
+    @tag :slow
     test "back button navigates to role list", %{conn: conn} do
       role = create_role()
 
diff --git a/test/mv_web/live/role_live_test.exs b/test/mv_web/live/role_live_test.exs
index d3db337..8cac22a 100644
--- a/test/mv_web/live/role_live_test.exs
+++ b/test/mv_web/live/role_live_test.exs
@@ -98,6 +98,7 @@ defmodule MvWeb.RoleLiveTest do
       %{conn: conn, actor: system_actor, user: user}
     end
 
+    @tag :slow
     test "mounts successfully", %{conn: conn} do
       {:ok, _view, _html} = live(conn, "/admin/roles")
     end
@@ -388,6 +389,7 @@ defmodule MvWeb.RoleLiveTest do
       %{conn: conn, actor: system_actor, user: user}
     end
 
+    @tag :slow
     test "deletes non-system role", %{conn: conn} do
       role = create_role()
 
diff --git a/test/mv_web/live/user_live/show_test.exs b/test/mv_web/live/user_live/show_test.exs
index feb4be6..ccea401 100644
--- a/test/mv_web/live/user_live/show_test.exs
+++ b/test/mv_web/live/user_live/show_test.exs
@@ -23,6 +23,7 @@ defmodule MvWeb.UserLive.ShowTest do
   end
 
   describe "mount and display" do
+    @tag :slow
     test "mounts successfully with valid user ID", %{conn: conn, user: user} do
       conn = conn_with_oidc_user(conn)
       {:ok, _view, html} = live(conn, ~p"/users/#{user.id}")
@@ -55,6 +56,7 @@ defmodule MvWeb.UserLive.ShowTest do
       assert html =~ gettext("Not enabled")
     end
 
+    @tag :slow
     test "displays linked member when present", %{conn: conn} do
       system_actor = Mv.Helpers.SystemActor.get_system_actor()
 
@@ -108,6 +110,7 @@ defmodule MvWeb.UserLive.ShowTest do
   end
 
   describe "system actor user" do
+    @tag :slow
     test "redirects to user list when viewing system actor user", %{conn: conn} do
       system_actor = Mv.Helpers.SystemActor.get_system_actor()
       conn = conn_with_oidc_user(conn)
diff --git a/test/mv_web/member_live/index_custom_fields_display_test.exs b/test/mv_web/member_live/index_custom_fields_display_test.exs
index 287a915..04d7a8a 100644
--- a/test/mv_web/member_live/index_custom_fields_display_test.exs
+++ b/test/mv_web/member_live/index_custom_fields_display_test.exs
@@ -161,6 +161,7 @@ defmodule MvWeb.MemberLive.IndexCustomFieldsDisplayTest do
     }
   end
 
+  @tag :slow
   test "displays custom field with show_in_overview: true", %{
     conn: conn,
     member1: _member1,
@@ -229,6 +230,7 @@ defmodule MvWeb.MemberLive.IndexCustomFieldsDisplayTest do
     assert html =~ "true" or html =~ "Yes" or html =~ "Ja"
   end
 
+  @tag :slow
   test "formats date custom field values correctly", %{conn: conn, member1: _member1} do
     conn = conn_with_oidc_user(conn)
     {:ok, _view, html} = live(conn, "/members")
@@ -237,6 +239,7 @@ defmodule MvWeb.MemberLive.IndexCustomFieldsDisplayTest do
     assert html =~ "15.05.1990"
   end
 
+  @tag :slow
   test "formats email custom field values correctly", %{conn: conn, member1: _member1} do
     conn = conn_with_oidc_user(conn)
     {:ok, _view, html} = live(conn, "/members")
diff --git a/test/mv_web/member_live/index_custom_fields_edge_cases_test.exs b/test/mv_web/member_live/index_custom_fields_edge_cases_test.exs
index cdf26f1..7d0ee45 100644
--- a/test/mv_web/member_live/index_custom_fields_edge_cases_test.exs
+++ b/test/mv_web/member_live/index_custom_fields_edge_cases_test.exs
@@ -12,6 +12,7 @@ defmodule MvWeb.MemberLive.IndexCustomFieldsEdgeCasesTest do
 
   alias Mv.Membership.{CustomField, Member}
 
+  @tag :slow
   test "displays custom field column even when no members have values", %{conn: conn} do
     system_actor = Mv.Helpers.SystemActor.get_system_actor()
 
@@ -51,6 +52,7 @@ defmodule MvWeb.MemberLive.IndexCustomFieldsEdgeCasesTest do
     assert html =~ field.name
   end
 
+  @tag :slow
   test "displays very long custom field values correctly", %{conn: conn} do
     system_actor = Mv.Helpers.SystemActor.get_system_actor()
 
@@ -94,6 +96,7 @@ defmodule MvWeb.MemberLive.IndexCustomFieldsEdgeCasesTest do
     assert html =~ "A" or html =~ long_value
   end
 
+  @tag :slow
   test "handles multiple custom fields with show_in_overview correctly", %{conn: conn} do
     system_actor = Mv.Helpers.SystemActor.get_system_actor()
 
diff --git a/test/mv_web/user_live/index_test.exs b/test/mv_web/user_live/index_test.exs
index b51fd15..92f11a1 100644
--- a/test/mv_web/user_live/index_test.exs
+++ b/test/mv_web/user_live/index_test.exs
@@ -3,6 +3,7 @@ defmodule MvWeb.UserLive.IndexTest do
   import Phoenix.LiveViewTest
 
   describe "basic functionality" do
+    @tag :slow
     test "displays users in a table", %{conn: conn} do
       # Create test users
       _user1 = create_test_user(%{email: "alice@example.com", oidc_id: "alice123"})
@@ -26,6 +27,7 @@ defmodule MvWeb.UserLive.IndexTest do
       %{users: [user_a, user_z, user_m]}
     end
 
+    @tag :slow
     test "initially sorts by email ascending", %{conn: conn} do
       conn = conn_with_oidc_user(conn)
       {:ok, _view, html} = live(conn, "/users")
@@ -43,6 +45,7 @@ defmodule MvWeb.UserLive.IndexTest do
       assert mike_pos < zulu_pos, "mike@example.com should appear before zulu@example.com"
     end
 
+    @tag :slow
     test "can sort email descending by clicking sort button", %{conn: conn} do
       conn = conn_with_oidc_user(conn)
       {:ok, view, _html} = live(conn, "/users")
@@ -74,6 +77,7 @@ defmodule MvWeb.UserLive.IndexTest do
       %{users: [user1, user2]}
     end
 
+    @tag :slow
     test "select all automatically checks when all individual users are selected", %{
       conn: conn,
       users: [user1, user2]
@@ -184,6 +188,7 @@ defmodule MvWeb.UserLive.IndexTest do
   end
 
   describe "member linking display" do
+    @tag :slow
     test "displays linked member name in user list", %{conn: conn} do
       system_actor = Mv.Helpers.SystemActor.get_system_actor()
 
diff --git a/test/seeds_test.exs b/test/seeds_test.exs
index e40a23f..316b99f 100644
--- a/test/seeds_test.exs
+++ b/test/seeds_test.exs
@@ -44,6 +44,7 @@ defmodule Mv.SeedsTest do
   end
 
   describe "Seeds script" do
+    @tag :slow
     test "runs successfully and creates basic data", %{actor: actor} do
       # Smoke test: verify seeds created essential data structures
       {:ok, users} = Ash.read(Mv.Accounts.User, actor: actor)
@@ -57,6 +58,7 @@ defmodule Mv.SeedsTest do
       assert length(roles) >= 5, "Seeds should create at least 5 authorization roles"
     end
 
+    @tag :slow
     test "is idempotent when run multiple times", %{actor: actor} do
       # Seeds already run once in setup - count current state
       {:ok, users_count_1} = Ash.read(Mv.Accounts.User, actor: actor)