diff --git a/api/src/routes/auth.ts b/api/src/routes/auth.ts
index 001a200..f8dad37 100644
--- a/api/src/routes/auth.ts
+++ b/api/src/routes/auth.ts
@@ -14,6 +14,7 @@ import { toDateTime } from '@app/shared/utils/time';
 import { logger } from '../services/logging/logger';
 const querystring = require('querystring');
 import { performance } from 'perf_hooks';
+import { CacheService } from '../services/cache/cache';
 
 
 function parseJwt(token) {
@@ -189,8 +190,31 @@ passport.deserializeUser(function (user, cb) {
         let con;
 
         try {
-            let t;
+            //cache lookup
+            let t = performance.now();
+            const cachedData: UserData | undefined = userCache.Get(memberID);
+            timings.cache_lookup = performance.now() - t;
 
+            if (cachedData) {
+                timings.total = performance.now() - start;
+
+                logger.info(
+                    'profiling',
+                    'passport.deserializeUser (cache hit)',
+                    {
+                        memberId: memberID,
+                        cache_hit: true,
+                        source: 'cache',
+                        total_ms: timings.total,
+                        breakdown_ms: timings,
+                    },
+                    'profiling'
+                );
+
+                return cb(null, cachedData);
+            }
+
+            //cache miss, db load
             t = performance.now();
             con = await pool.getConnection();
             timings.getConnection = performance.now() - t;
@@ -202,30 +226,30 @@ passport.deserializeUser(function (user, cb) {
             );
             timings.memberQuery = performance.now() - t;
 
-            const userData: {
-                id: number;
-                name: string;
-                roles: Role[];
-                state: MemberState;
-                discord_id?: string;
-            } = userResults[0];
+            const userData: UserData = userResults[0];
 
             t = performance.now();
-            const userRoles = await getUserRoles(memberID);
+            userData.roles = await getUserRoles(memberID) || [];
             timings.roles = performance.now() - t;
-            userData.roles = userRoles || [];
 
             t = performance.now();
             userData.state = await getUserState(memberID);
             timings.state = performance.now() - t;
 
-            // 📊 PROFILING LOG
+            t = performance.now();
+            userCache.Set(userData.id, userData);
+            timings.cache_set = performance.now() - t;
+
+            timings.total = performance.now() - start;
+
             logger.info(
                 'profiling',
-                'passport.deserializeUser completed',
+                'passport.deserializeUser (db load)',
                 {
                     memberId: memberID,
-                    total_ms: performance.now() - start,
+                    cache_hit: false,
+                    source: 'db',
+                    total_ms: timings.total,
                     breakdown_ms: timings,
                 },
                 'profiling'
@@ -243,14 +267,12 @@ passport.deserializeUser(function (user, cb) {
                 }
             );
             return cb(error);
-
         } finally {
             if (con) con.release();
         }
     });
 });
 
-
 declare global {
     namespace Express {
         interface Request {
@@ -265,5 +287,15 @@ declare global {
     }
 }
 
+export interface UserData {
+    id: number;
+    name: string;
+    roles: Role[];
+    state: MemberState;
+    discord_id?: string;
+}
 
-export const authRouter = router;
\ No newline at end of file
+const userCache = new CacheService<number, UserData>();
+
+export const authRouter = router;
+export const memberCache = userCache;
\ No newline at end of file
diff --git a/api/src/services/cache/cache.ts b/api/src/services/cache/cache.ts
new file mode 100644
index 0000000..22c6fb8
--- /dev/null
+++ b/api/src/services/cache/cache.ts
@@ -0,0 +1,19 @@
+export class CacheService<Key, Value> {
+    private cacheMap: Map<Key, Value>
+
+    constructor() {
+        this.cacheMap = new Map<Key, Value>();
+    }
+
+    public Get(key: Key): Value {
+        return this.cacheMap.get(key)
+    }
+
+    public Set(key: Key, value: Value) {
+        this.cacheMap.set(key, value);
+    }
+
+    public Invalidate(key: Key): boolean {
+        return this.cacheMap.delete(key);
+    }
+}
\ No newline at end of file
diff --git a/api/src/services/db/memberService.ts b/api/src/services/db/memberService.ts
index d1a2db5..a0776d3 100644
--- a/api/src/services/db/memberService.ts
+++ b/api/src/services/db/memberService.ts
@@ -1,6 +1,8 @@
 import { Role } from "@app/shared/types/roles";
 import pool from "../../db";
 import { Member, MemberCardDetails, MemberLight, memberSettings, MemberState } from '@app/shared/types/member'
+import { logger } from "../logging/logger";
+import { memberCache } from "../../routes/auth";
 
 export async function getUserData(userID: number): Promise<Member> {
   const sql = `SELECT * FROM view_member_rank_unit_status_latest WHERE member_id = ?`;
@@ -9,10 +11,16 @@ export async function getUserData(userID: number): Promise<Member> {
 }
 
 export async function setUserState(userID: number, state: MemberState) {
-  const sql = `UPDATE members
+  try {
+    const sql = `UPDATE members
         SET state = ?
         WHERE id = ?;`;
-  return await pool.query(sql, [state, userID]);
+    return await pool.query(sql, [state, userID]);
+  } catch (error) {
+    logger.error('app', 'Error setting user state', error);
+  } finally {
+    memberCache.Invalidate(userID);
+  }
 }
 
 export async function getUserState(user: number): Promise<MemberState> {
diff --git a/api/src/services/db/rolesService.ts b/api/src/services/db/rolesService.ts
index 7a857ec..efb58ee 100644
--- a/api/src/services/db/rolesService.ts
+++ b/api/src/services/db/rolesService.ts
@@ -1,12 +1,20 @@
 import { MemberLight } from '@app/shared/types/member';
 import pool from '../../db';
 import { Role, RoleSummary } from '@app/shared/types/roles'
+import { logger } from '../logging/logger';
+import { memberCache } from '../../routes/auth';
 
 export async function assignUserGroup(userID: number, roleID: number) {
-    const sql = `INSERT INTO members_roles (member_id, role_id) VALUES (?, ?);`;
-    const params = [userID, roleID];
+    try {
+        const sql = `INSERT INTO members_roles (member_id, role_id) VALUES (?, ?);`;
+        const params = [userID, roleID];
 
-    return await pool.query(sql, params);
+        return await pool.query(sql, params);
+    } catch (error) {
+        logger.error('app', 'Failed to assign user group', error);
+    } finally {
+        memberCache.Invalidate(userID);
+    }
 }
 
 export async function createGroup(name: string, color: string, description: string) {