diff --git a/.yarn/versions/ecb1a3b6.yml b/.yarn/versions/ecb1a3b6.yml
new file mode 100644
index 0000000..85ee0e5
--- /dev/null
+++ b/.yarn/versions/ecb1a3b6.yml
@@ -0,0 +1,3 @@
+releases:
+  "@aoi-js/frontend": patch
+  "@aoi-js/server": patch
diff --git a/apps/frontend/src/components/solution/SolutionList.vue b/apps/frontend/src/components/solution/SolutionList.vue
index 764eef0..606b92e 100644
--- a/apps/frontend/src/components/solution/SolutionList.vue
+++ b/apps/frontend/src/components/solution/SolutionList.vue
@@ -50,6 +50,7 @@ import { computed, ref } from 'vue'
 import { useAppState } from '@/stores/app'
 import { useContestProblemTitle } from '@/utils/contest/problem/inject'
 import type { ISolutionDTO } from './types'
+import { useRouteQuery } from '@vueuse/router'
 
 const { t } = useI18n()
 const app = useAppState()
@@ -78,7 +79,7 @@ const headersProblem = [
   { title: t('common.submitted-at'), key: 'submittedAt', align: 'start', sortable: false }
 ] as const
 
-const userId = ref(app.userId as string)
+const userId = useRouteQuery('userId')
 
 const {
   page,
diff --git a/apps/frontend/src/components/utils/RanklistViewer.vue b/apps/frontend/src/components/utils/RanklistViewer.vue
index b153777..5a65159 100644
--- a/apps/frontend/src/components/utils/RanklistViewer.vue
+++ b/apps/frontend/src/components/utils/RanklistViewer.vue
@@ -22,7 +22,10 @@
             <tr v-for="(man, i) in value.participant.list" :key="i">
               <td>{{ man.rank }}</td>
               <td class="u-flex u-items-center">
-                <PrincipalProfile :principal-id="man.userId" />
+                <PrincipalProfile
+                  :principal-id="man.userId"
+                  :to="admin ? participantUrl(man.userId) : undefined"
+                />
                 <div v-if="man.tags" class="u-pl-2 u-flex u-items-center u-gap-2">
                   <div v-for="(tag, i) of man.tags" :key="i">
                     <VTooltip v-if="tag.startsWith('!star:')" :text="tag.slice(6)">
@@ -55,11 +58,17 @@ import { renderMarkdown } from '@/utils/md'
 import PrincipalProfile from '@/components/utils/PrincipalProfile.vue'
 import { useI18n } from 'vue-i18n'
 import RanklistTopstars from '../contest/RanklistTopstars.vue'
+import { useContestCapability, useContestData } from '@/utils/contest/inject'
 
 const { t } = useI18n()
 const props = defineProps<{
   endpoint: string
 }>()
+
+const admin = useContestCapability('admin')
+const contest = useContestData()
+const participantUrl = (userId: string) =>
+  `/org/${contest.value.orgId}/contest/${contest.value._id}/participant/${userId}`
 </script>
 
 <i18n>
diff --git a/apps/frontend/src/pages/org/[orgId]/contest/[contestId]/participant/[userId].vue b/apps/frontend/src/pages/org/[orgId]/contest/[contestId]/participant/[userId].vue
index 1dfc8b7..30419c2 100644
--- a/apps/frontend/src/pages/org/[orgId]/contest/[contestId]/participant/[userId].vue
+++ b/apps/frontend/src/pages/org/[orgId]/contest/[contestId]/participant/[userId].vue
@@ -2,18 +2,27 @@
   <VCardText>
     <PrincipalProfile :principal-id="userId" />
   </VCardText>
-  <VDivider />
-  <SettingsEditor v-if="admin" :endpoint="`contest/${contestId}/participant/admin/${userId}`">
-    <template v-slot="scoped">
-      <VCombobox v-model="scoped.value.tags" :label="t('term.tags')" multiple chips />
-    </template>
-  </SettingsEditor>
+  <template v-if="admin">
+    <VDivider />
+    <SettingsEditor :endpoint="`contest/${contestId}/participant/admin/${userId}`">
+      <template v-slot="scoped">
+        <VCombobox v-model="scoped.value.tags" :label="t('term.tags')" multiple chips />
+      </template>
+    </SettingsEditor>
+    <VDivider />
+    <VCardActions>
+      <VBtn
+        :to="`/org/${orgId}/contest/${contestId}/solution?userId=${userId}`"
+        :text="t('goto-solutions')"
+      />
+    </VCardActions>
+  </template>
 </template>
 
 <script setup lang="ts">
 import { useI18n } from 'vue-i18n'
 import type { IContestDTO } from '@/components/contest/types'
-import { useContestCapability } from '@/utils/contest/inject'
+import { useContestCapability, useContestSettings } from '@/utils/contest/inject'
 import PrincipalProfile from '@/components/utils/PrincipalProfile.vue'
 import SettingsEditor from '@/components/utils/SettingsEditor.vue'
 
@@ -27,3 +36,10 @@ defineProps<{
 const { t } = useI18n()
 const admin = useContestCapability('admin')
 </script>
+
+<i18n>
+en:
+  goto-solutions: Go to solutions
+zh-Hans:
+  goto-solutions: 查看提交
+</i18n>
diff --git a/apps/server/src/routes/contest/admin.ts b/apps/server/src/routes/contest/admin.ts
index 90a47e3..9ae57d2 100644
--- a/apps/server/src/routes/contest/admin.ts
+++ b/apps/server/src/routes/contest/admin.ts
@@ -60,21 +60,23 @@ export const contestAdminRoutes = defineRoutes(async (s) => {
       }
     },
     async (req) => {
-      const { modifiedCount } = await solutions.updateOne(
+      const { modifiedCount } = await solutions.updateMany(
         {
           contestId: req.inject(kContestContext)._contestId,
           state: SolutionState.CREATED
         },
-        {
-          $set: {
-            state: SolutionState.PENDING,
-            submittedAt: req._now,
-            score: 0,
-            status: '',
-            metrics: {},
-            message: ''
+        [
+          {
+            $set: {
+              state: SolutionState.PENDING,
+              submittedAt: { $convert: { input: '$$NOW', to: 'double' } },
+              score: 0,
+              status: '',
+              metrics: {},
+              message: ''
+            }
           }
-        },
+        ],
         { ignoreUndefined: true }
       )
       return { modifiedCount }
@@ -120,13 +122,15 @@ export const contestAdminRoutes = defineRoutes(async (s) => {
           _id: req.inject(kContestContext)._contestId,
           ranklists: { $exists: true, $ne: [] }
         },
-        {
-          $set: {
-            ranklistUpdatedAt: req._now,
-            ranklistState: ContestRanklistState.INVALID
+        [
+          {
+            $set: {
+              ranklistUpdatedAt: { $convert: { input: '$$NOW', to: 'double' } },
+              ranklistState: ContestRanklistState.INVALID
+            }
           },
-          $unset: req.body.resetRunner ? { ranklistRunnerId: 1 } : {}
-        },
+          ...(req.body.resetRunner ? [{ $unset: ['ranklistRunnerId'] }] : [])
+        ],
         { ignoreUndefined: true }
       )
       return 0
diff --git a/apps/server/src/routes/contest/participant/index.ts b/apps/server/src/routes/contest/participant/index.ts
index 5c8cb39..7040276 100644
--- a/apps/server/src/routes/contest/participant/index.ts
+++ b/apps/server/src/routes/contest/participant/index.ts
@@ -127,10 +127,14 @@ const contestParticipantAdminRoutes = defineRoutes(async (s) => {
     async (req) => {
       const ctx = req.inject(kContestContext)
       const userId = new BSON.UUID(req.params.userId)
-      await contestParticipants.updateOne(
-        { contestId: ctx._contestId, userId },
-        { $set: { tags: req.body.tags, updatedAt: req._now } }
-      )
+      await contestParticipants.updateOne({ contestId: ctx._contestId, userId }, [
+        {
+          $set: {
+            tags: req.body.tags,
+            updatedAt: { $convert: { input: '$$NOW', to: 'double' } }
+          }
+        }
+      ])
       return 0
     }
   )
diff --git a/apps/server/src/routes/contest/problem/index.ts b/apps/server/src/routes/contest/problem/index.ts
index 9d115ef..1914b31 100644
--- a/apps/server/src/routes/contest/problem/index.ts
+++ b/apps/server/src/routes/contest/problem/index.ts
@@ -264,6 +264,8 @@ const problemViewRoutes = defineRoutes(async (s) => {
         metrics: {},
         status: '',
         message: '',
+        // createdAt is only a reference time,
+        // so use local time here
         createdAt: req._now
       })
       const uploadUrl = await getUploadUrl(oss, solutionDataKey(insertedId), {
diff --git a/apps/server/src/routes/contest/solution/index.ts b/apps/server/src/routes/contest/solution/index.ts
index 844b715..7943426 100644
--- a/apps/server/src/routes/contest/solution/index.ts
+++ b/apps/server/src/routes/contest/solution/index.ts
@@ -52,16 +52,18 @@ const solutionScopedRoutes = defineRoutes(async (s) => {
         userId: admin ? undefined : req.user.userId,
         state: admin ? undefined : SolutionState.CREATED
       },
-      {
-        $set: {
-          state: SolutionState.PENDING,
-          submittedAt: req._now,
-          score: 0,
-          status: '',
-          metrics: {},
-          message: ''
+      [
+        {
+          $set: {
+            state: SolutionState.PENDING,
+            submittedAt: { $convert: { input: '$$NOW', to: 'double' } },
+            score: 0,
+            status: '',
+            metrics: {},
+            message: ''
+          }
         }
-      },
+      ],
       { ignoreUndefined: true }
     )
     if (modifiedCount === 0) return rep.notFound()
diff --git a/apps/server/src/routes/problem/solution.ts b/apps/server/src/routes/problem/solution.ts
index c8a7d03..89e707f 100644
--- a/apps/server/src/routes/problem/solution.ts
+++ b/apps/server/src/routes/problem/solution.ts
@@ -33,6 +33,8 @@ const solutionScopedRoutes = defineRoutes(async (s) => {
       {
         $set: {
           state: SolutionState.PENDING,
+          // Problem solutions are not synced with rankers,
+          // so we can use local time here
           submittedAt: req._now,
           score: 0,
           status: '',
diff --git a/apps/server/src/routes/runner/solution.ts b/apps/server/src/routes/runner/solution.ts
index d65ca20..0cdb729 100644
--- a/apps/server/src/routes/runner/solution.ts
+++ b/apps/server/src/routes/runner/solution.ts
@@ -101,7 +101,6 @@ const runnerTaskRoutes = defineRoutes(async (s) => {
       }
     },
     async (req, rep) => {
-      const now = req._now
       const ctx = req.inject(kRunnerSolutionContext)
       const value = await solutions.findOneAndUpdate(
         {
@@ -109,7 +108,9 @@ const runnerTaskRoutes = defineRoutes(async (s) => {
           taskId: ctx._taskId,
           state: { $in: [SolutionState.QUEUED, SolutionState.RUNNING] }
         },
-        { $set: { state: SolutionState.COMPLETED, completedAt: now } },
+        // Since completedAt is only for reference,
+        // use local time here
+        { $set: { state: SolutionState.COMPLETED, completedAt: req._now } },
         { projection: { userId: 1, problemId: 1, contestId: 1, score: 1, status: 1 } }
       )
       if (!value) return rep.conflict()
@@ -120,17 +121,19 @@ const runnerTaskRoutes = defineRoutes(async (s) => {
             contestId: value.contestId,
             [`results.${value.problemId}.lastSolutionId`]: value._id
           },
-          {
-            $set: {
-              [`results.${value.problemId}.lastSolution`]: {
-                _id: value._id,
-                score: value.score,
-                status: value.status,
-                completedAt: now
-              },
-              updatedAt: now
+          [
+            {
+              $set: {
+                [`results.${value.problemId}.lastSolution`]: {
+                  _id: value._id,
+                  score: value.score,
+                  status: value.status,
+                  completedAt: req._now
+                },
+                updatedAt: { $convert: { input: '$$NOW', to: 'double' } }
+              }
             }
-          }
+          ]
         )
         if (modifiedCount) {
           // update contest ranklist state
@@ -139,12 +142,14 @@ const runnerTaskRoutes = defineRoutes(async (s) => {
               _id: value.contestId,
               ranklists: { $exists: true, $ne: [] }
             },
-            {
-              $set: {
-                ranklistUpdatedAt: now,
-                ranklistState: ContestRanklistState.INVALID
+            [
+              {
+                $set: {
+                  ranklistUpdatedAt: { $convert: { input: '$$NOW', to: 'double' } },
+                  ranklistState: ContestRanklistState.INVALID
+                }
               }
-            }
+            ]
           )
         }
       } else {