diff --git a/src/controllers/api/artifactsController.ts b/src/controllers/api/artifactsController.ts
index 6b6f6248..3445742b 100644
--- a/src/controllers/api/artifactsController.ts
+++ b/src/controllers/api/artifactsController.ts
@@ -10,7 +10,7 @@ const artifactsController: RequestHandler = async (req, res) => {
 
     try {
         // eslint-disable-next-line @typescript-eslint/no-unsafe-argument, @typescript-eslint/no-unsafe-call
-        const artifactsData = getJSONfromString(req.body.toString()) as IArtifactsRequest;
+        const artifactsData = getJSONfromString(String(req.body)) as IArtifactsRequest;
         // eslint-disable-next-line @typescript-eslint/no-unsafe-argument
         const upgradeModId = await upgradeMod(artifactsData, accountId);
         res.send(upgradeModId);
diff --git a/src/controllers/api/claimCompletedRecipeController.ts b/src/controllers/api/claimCompletedRecipeController.ts
index 27267953..53635bdc 100644
--- a/src/controllers/api/claimCompletedRecipeController.ts
+++ b/src/controllers/api/claimCompletedRecipeController.ts
@@ -39,8 +39,8 @@ export const claimCompletedRecipeController: RequestHandler = async (req, res) =
 
     const recipe = getRecipe(pendingRecipe.ItemType);
     if (!recipe) {
-        logger.error(`no completed item found for recipe ${pendingRecipe._id}`);
-        throw new Error(`no completed item found for recipe ${pendingRecipe._id}`);
+        logger.error(`no completed item found for recipe ${pendingRecipe._id?.toString()}`);
+        throw new Error(`no completed item found for recipe ${pendingRecipe._id?.toString()}`);
     }
 
     if (req.query.cancel) {
diff --git a/src/controllers/api/focusController.ts b/src/controllers/api/focusController.ts
index 9b6129ac..83ce11c3 100644
--- a/src/controllers/api/focusController.ts
+++ b/src/controllers/api/focusController.ts
@@ -10,8 +10,8 @@ export const focusController: RequestHandler = async (req, res) => {
     const accountId = await getAccountIdForRequest(req);
     switch (req.query.op) {
         default:
-            logger.error("Unhandled focus op type: " + req.query.op);
-            logger.debug(req.body.toString());
+            logger.error("Unhandled focus op type: " + String(req.query.op));
+            logger.debug(String(req.body));
             res.end();
             break;
         case FocusOperation.InstallLens: {
diff --git a/src/controllers/api/fusionTreasuresController.ts b/src/controllers/api/fusionTreasuresController.ts
index e03af407..e1c0777f 100644
--- a/src/controllers/api/fusionTreasuresController.ts
+++ b/src/controllers/api/fusionTreasuresController.ts
@@ -22,7 +22,7 @@ const parseFusionTreasure = (name: string, count: number): IFusionTreasure => {
 export const fusionTreasuresController: RequestHandler = async (req, res) => {
     const accountId = await getAccountIdForRequest(req);
     const inventory = await getInventory(accountId);
-    const request = JSON.parse(req.body.toString() as string) as IFusionTreasureRequest;
+    const request = JSON.parse(String(req.body)) as IFusionTreasureRequest;
 
     const oldTreasure = parseFusionTreasure(request.oldTreasureName, -1);
     const newTreasure = parseFusionTreasure(request.newTreasureName, 1);
diff --git a/src/controllers/api/getVendorInfoController.ts b/src/controllers/api/getVendorInfoController.ts
index e7d80ba5..2cf20770 100644
--- a/src/controllers/api/getVendorInfoController.ts
+++ b/src/controllers/api/getVendorInfoController.ts
@@ -133,6 +133,6 @@ export const getVendorInfoController: RequestHandler = (req, res) => {
             break;
 
         default:
-            throw new Error(`Unknown vendor: ${req.query.vendor}`);
+            throw new Error(`Unknown vendor: ${String(req.query.vendor)}`);
     }
 };
diff --git a/src/controllers/api/gildWeaponController.ts b/src/controllers/api/gildWeaponController.ts
index 0b77513f..8740764f 100644
--- a/src/controllers/api/gildWeaponController.ts
+++ b/src/controllers/api/gildWeaponController.ts
@@ -27,20 +27,20 @@ interface IGildWeaponRequest {
 // eslint-disable-next-line @typescript-eslint/no-misused-promises
 export const gildWeaponController: RequestHandler = async (req, res) => {
     const accountId = await getAccountIdForRequest(req);
-    const data: IGildWeaponRequest = getJSONfromString(String(req.body));
+    const data = getJSONfromString(String(req.body)) as IGildWeaponRequest;
     data.ItemId = String(req.query.ItemId);
     if (!modularWeaponCategory.includes(req.query.Category as WeaponTypeInternal | "Hoverboards")) {
-        throw new Error(`Unknown modular weapon Category: ${req.query.Category}`);
+        throw new Error(`Unknown modular weapon Category: ${String(req.query.Category)}`);
     }
     data.Category = req.query.Category as WeaponTypeInternal | "Hoverboards";
 
     const inventory = await getInventory(accountId);
     if (!inventory[data.Category]) {
-        throw new Error(`Category ${req.query.Category} not found in inventory`);
+        throw new Error(`Category ${String(req.query.Category)} not found in inventory`);
     }
     const weaponIndex = inventory[data.Category].findIndex(x => String(x._id) === data.ItemId);
     if (weaponIndex === -1) {
-        throw new Error(`Weapon with ${data.ItemId} not found in category ${req.query.Category}`);
+        throw new Error(`Weapon with ${data.ItemId} not found in category ${String(req.query.Category)}`);
     }
 
     const weapon = inventory[data.Category][weaponIndex];
diff --git a/src/controllers/api/infestedFoundryController.ts b/src/controllers/api/infestedFoundryController.ts
index cbfa0fa8..3b8d225a 100644
--- a/src/controllers/api/infestedFoundryController.ts
+++ b/src/controllers/api/infestedFoundryController.ts
@@ -59,7 +59,7 @@ export const infestedFoundryController: RequestHandler = async (req, res) => {
             break;
 
         default:
-            throw new Error(`unhandled infestedFoundry mode: ${req.query.mode}`);
+            throw new Error(`unhandled infestedFoundry mode: ${String(req.query.mode)}`);
     }
 };
 
diff --git a/src/controllers/api/missionInventoryUpdateController.ts b/src/controllers/api/missionInventoryUpdateController.ts
index e2723a51..f57d3d3c 100644
--- a/src/controllers/api/missionInventoryUpdateController.ts
+++ b/src/controllers/api/missionInventoryUpdateController.ts
@@ -51,7 +51,7 @@ const missionInventoryUpdateController: RequestHandler = async (req, res): Promi
 
     try {
         // eslint-disable-next-line @typescript-eslint/no-unsafe-argument, @typescript-eslint/no-unsafe-call
-        const lootInventory = getJSONfromString(req.body.toString()) as IMissionInventoryUpdateRequest;
+        const lootInventory = getJSONfromString(String(req.body)) as IMissionInventoryUpdateRequest;
 
         logger.debug("missionInventoryUpdate with lootInventory =", lootInventory);
 
diff --git a/src/controllers/api/trainingResultController.ts b/src/controllers/api/trainingResultController.ts
index 59ab9c4d..4c2442dd 100644
--- a/src/controllers/api/trainingResultController.ts
+++ b/src/controllers/api/trainingResultController.ts
@@ -4,6 +4,7 @@ import { getInventory } from "@/src/services/inventoryService";
 import { IMongoDate } from "@/src/types/commonTypes";
 import { RequestHandler } from "express";
 import { unixTimesInMs } from "@/src/constants/timeConstants";
+import { IInventoryChanges } from "@/src/types/purchaseTypes";
 
 interface ITrainingResultsRequest {
     numLevelsGained: number;
@@ -12,7 +13,7 @@ interface ITrainingResultsRequest {
 interface ITrainingResultsResponse {
     NewTrainingDate: IMongoDate;
     NewLevel: number;
-    InventoryChanges: any[];
+    InventoryChanges: IInventoryChanges;
 }
 
 // eslint-disable-next-line @typescript-eslint/no-misused-promises
@@ -36,7 +37,7 @@ const trainingResultController: RequestHandler = async (req, res): Promise<void>
             $date: { $numberLong: changedinventory.TrainingDate.getTime().toString() }
         },
         NewLevel: trainingResults.numLevelsGained == 1 ? changedinventory.PlayerLevel : inventory.PlayerLevel,
-        InventoryChanges: []
+        InventoryChanges: {}
     } satisfies ITrainingResultsResponse);
 };
 
diff --git a/src/controllers/custom/addItemController.ts b/src/controllers/custom/addItemController.ts
index 7488710f..c542b810 100644
--- a/src/controllers/custom/addItemController.ts
+++ b/src/controllers/custom/addItemController.ts
@@ -10,15 +10,17 @@ const addItemController: RequestHandler = async (req, res) => {
     const request = toAddItemRequest(req.body);
 
     switch (request.type) {
-        case ItemType.Powersuit:
+        case ItemType.Powersuit: {
             const powersuit = await addPowerSuit(request.InternalName, accountId);
             res.json(powersuit);
             return;
-        case ItemType.Weapon:
+        }
+        case ItemType.Weapon: {
             const weaponType = getWeaponType(request.InternalName);
             const weapon = await addEquipment(weaponType, request.InternalName, accountId);
             res.json(weapon);
             break;
+        }
         default:
             res.status(400).json({ error: "something went wrong" });
             break;
diff --git a/src/services/configService.ts b/src/services/configService.ts
index bcb2ff4d..84da5242 100644
--- a/src/services/configService.ts
+++ b/src/services/configService.ts
@@ -6,7 +6,7 @@ import { logger } from "@/src/utils/logger";
 const rootDir = path.join(__dirname, "../..");
 const repoDir = path.basename(rootDir) == "build" ? path.join(rootDir, "..") : rootDir;
 const configPath = path.join(repoDir, "config.json");
-export const config: IConfig = JSON.parse(fs.readFileSync(configPath, "utf-8"));
+export const config = JSON.parse(fs.readFileSync(configPath, "utf-8")) as IConfig;
 
 let amnesia = false;
 fs.watchFile(configPath, () => {
diff --git a/src/services/inventoryService.ts b/src/services/inventoryService.ts
index d67d7e73..eb298966 100644
--- a/src/services/inventoryService.ts
+++ b/src/services/inventoryService.ts
@@ -218,7 +218,7 @@ export const addItem = async (
                 }
             }
             break;
-        case "Weapons":
+        case "Weapons": {
             const weaponType = getWeaponType(typeName);
             const weapon = await addEquipment(weaponType, typeName, accountId);
             await updateSlots(accountId, InventorySlot.WEAPONS, 0, 1);
@@ -228,6 +228,7 @@ export const addItem = async (
                     [weaponType]: [weapon]
                 }
             };
+        }
         case "Upgrades": {
             const inventory = await getInventory(accountId);
             const changes = [
@@ -263,7 +264,7 @@ export const addItem = async (
         }
         case "Types":
             switch (typeName.substr(1).split("/")[2]) {
-                case "Sentinels":
+                case "Sentinels": {
                     // TOOD: Sentinels should also grant their DefaultUpgrades & SentinelWeapon.
                     const sentinel = await addSentinel(typeName, accountId);
                     await updateSlots(accountId, InventorySlot.SENTINELS, 0, 1);
@@ -273,6 +274,7 @@ export const addItem = async (
                             Sentinels: [sentinel]
                         }
                     };
+                }
                 case "Items": {
                     switch (typeName.substr(1).split("/")[3]) {
                         case "ShipDecos": {
@@ -328,7 +330,8 @@ export const addItem = async (
                         };
                     }
                     break;
-                case "Restoratives": // Codex Scanner, Remote Observer, Starburst
+                case "Restoratives": {
+                    // Codex Scanner, Remote Observer, Starburst
                     const inventory = await getInventory(accountId);
                     const consumablesChanges = [
                         {
@@ -343,6 +346,7 @@ export const addItem = async (
                             Consumables: consumablesChanges
                         }
                     };
+                }
             }
             break;
     }
diff --git a/src/services/shipService.ts b/src/services/shipService.ts
index f43772f1..a0be55c6 100644
--- a/src/services/shipService.ts
+++ b/src/services/shipService.ts
@@ -23,8 +23,8 @@ export const getShip = async (shipId: Types.ObjectId, fieldSelection: string = "
     const ship = await Ship.findOne({ _id: shipId }, fieldSelection);
 
     if (!ship) {
-        logger.error(`error finding a ship for account ${shipId}`);
-        throw new Error(`error finding a ship for account ${shipId}`);
+        logger.error(`error finding a ship for account ${String(shipId)}`);
+        throw new Error(`error finding a ship for account ${String(shipId)}`);
     }
 
     return ship;