diff --git a/src/app/api/upload/csv/route.ts b/src/app/api/upload/csv/route.ts
index f26e918..faf865d 100644
--- a/src/app/api/upload/csv/route.ts
+++ b/src/app/api/upload/csv/route.ts
@@ -13,7 +13,7 @@ function generateS3Key(userId: number, portfolioId: number, filename: string) {
   return key;
 }
 
-export async function GET(request: NextRequest) {
+export async function POST(request: NextRequest) {
   // For the moment, this api specifically handles uploads of csvs
 
   const body = await request.json();
diff --git a/src/app/components/portfolio/Toolbar.tsx b/src/app/components/portfolio/Toolbar.tsx
index 3ff9fdf..e3f747f 100644
--- a/src/app/components/portfolio/Toolbar.tsx
+++ b/src/app/components/portfolio/Toolbar.tsx
@@ -55,7 +55,11 @@ export function Toolbar({ portfolioId }: ToolbarProps) {
           setIsUploadCsvOpen={setModalIsOpen}
         />
       </NavigationMenuList>
-      <UploadCsvModal isOpen={modalIsOpen} setIsOpen={setModalIsOpen} />
+      <UploadCsvModal
+        isOpen={modalIsOpen}
+        setIsOpen={setModalIsOpen}
+        portfolioId={portfolioId}
+      />
     </NavigationMenu>
   );
 }
diff --git a/src/app/components/portfolio/UploadCsvModal.tsx b/src/app/components/portfolio/UploadCsvModal.tsx
index d91d8d8..2a619e4 100644
--- a/src/app/components/portfolio/UploadCsvModal.tsx
+++ b/src/app/components/portfolio/UploadCsvModal.tsx
@@ -9,63 +9,119 @@ import { Input } from "@/app/shadcn_components/ui/input";
 import { Label } from "@/app/shadcn_components/ui/label";
 import { useRouter } from "next/navigation";
 import { useMutation } from "@tanstack/react-query";
-import Link from "next/link";
+import { useSession } from "next-auth/react";
+
+async function generatePresignedUrl({
+  userId,
+  portfolioId,
+}: {
+  userId: number;
+  portfolioId: number;
+}) {
+  const body = JSON.stringify({ userId: userId, portfolioId: portfolioId });
+  console.log("body before: ", body);
+
+  const presignedResponse = await fetch(`/api/upload/csv`, {
+    method: "POST",
+    body: body,
+  });
+  if (!presignedResponse.ok) {
+    throw new Error("Network response was not ok");
+  }
+  const presignedUrl = await presignedResponse.json();
+  return presignedUrl;
+}
+
+async function uploadCsvToS3({
+  presignedUrl,
+  file,
+}: {
+  presignedUrl: string;
+  file: File;
+}) {
+  console.log("Uploading file to s3");
+  const upload = await fetch(presignedUrl, {
+    method: "PUT",
+    body: file,
+  });
+
+  if (!upload.ok) {
+    throw new Error("Upload failed.");
+  }
+
+  return upload;
+}
 
 export const SubmitPlan = ({
   buttonDisabled,
   goal,
   housingType,
   goalValue,
+  file,
+  portfolioId,
 }: {
   buttonDisabled: boolean;
   goal: string;
   housingType: string;
   goalValue: string;
+  file: File | null;
+  portfolioId: number;
 }) => {
   const router = useRouter();
+  const session = useSession();
+  // This state will hold the presignedUrl once it is available
+  const [presignedUrl, setPresignedUrl] = useState(null);
 
-  async function triggerPlanBuild() {
-    const requestBody = JSON.stringify({
-      goal: goal,
-      goalValue: goalValue,
-      housingType: housingType,
-    });
-
-    const response = await fetch("/api/portfolio/plan", {
-      method: "POST",
-      headers: {
-        "Content-Type": "application/json",
+  const { mutate: mutateUploadCsv, isLoading: isUploadLoading } = useMutation(
+    uploadCsvToS3,
+    {
+      onSuccess: (data) => {
+        return data;
+      },
+      onError: (error) => {
+        // handle error
+        console.error(error);
       },
-      body: requestBody,
-    });
-
-    if (!response.ok) {
-      throw new Error("Network response was not ok");
     }
+  );
 
-    return response.json();
-  }
-
-  const { mutate, isLoading } = useMutation(triggerPlanBuild, {
+  const { mutate, isLoading } = useMutation(generatePresignedUrl, {
     onSuccess: (data) => {
-      console.log("uploading csv");
-      // router.push(`/portfolio/${data.id}`);
+      // After the presigned URL has been generated, we can upload the file to S3
+      mutateUploadCsv({ presignedUrl: data.url, file: file });
     },
     onError: (error) => {
       // handle error
-      console.log(error);
+      console.error(error);
     },
   });
 
-  const handleSubmit = () => {
-    mutate();
+  if (!session.data) {
+    // The user is not logged in, redirect them to sign in
+    router.push("/");
+    return null;
+  }
+  const userId = session.data.user.dbId;
+
+  const handlePlanBuild = () => {
+    // The plan build is triggered by clicking submit which will:
+    // 1) Generate a pre-signed url to upload to
+    // 2) Upload the csv to the pre-signed url
+    // 3) Trigger the job to build the plan
+    // 4) Redirect the user to some loading page - this could be the portfolio page itself and we just trigger a regresh with skeleton cards for the properties
+    mutate({ userId: userId, portfolioId: portfolioId });
+
+    // mutateUploadCsv(presignedUrl);
+
+    // console.log("Redirect user to loading page");
+    // router.push("/portfolio/somewhere");
   };
 
   return (
     <button
       type="button"
       className="text-white inline-flex justify-center rounded-md border border-transparent bg-brandblue px-4 py-2 text-sm font-medium text-grey-900 hover:bg-hoverblue focus:outline-none focus-visible:ring-2 focus-visible:ring-blue-500 focus-visible:ring-offset-2 disabled:bg-gray-300 disabled:opacity-50"
-      onClick={handleSubmit}
+      onClick={handlePlanBuild}
       disabled={buttonDisabled || isLoading}
     >
       {isLoading ? "Creating..." : "Create"}
@@ -233,9 +289,11 @@ const goalValueOptions = [
 export default function UploadCsvModal({
   isOpen = false,
   setIsOpen,
+  portfolioId,
 }: {
   isOpen?: boolean;
   setIsOpen: (isOpen: boolean) => void;
+  portfolioId: number;
 }) {
   const [budget, setBudget] = useState<undefined | number>(undefined);
 
@@ -246,10 +304,6 @@ export default function UploadCsvModal({
 
   const [csvFile, setCsvFile] = useState<File | null>(null);
 
-  function handleFileChange(e: React.ChangeEvent<HTMLInputElement>) {
-    setCsvFile(e.target.files ? e.target.files[0] : null);
-  }
-
   function handleBudgeChange(e: React.ChangeEvent<HTMLInputElement>) {
     setBudget(e.target.valueAsNumber);
   }
@@ -447,6 +501,8 @@ export default function UploadCsvModal({
                       goal={goalValue}
                       housingType={housingType}
                       goalValue={goalValue}
+                      portfolioId={portfolioId}
+                      file={csvFile}
                     />
                   </div>
                 </Dialog.Panel>
diff --git a/src/app/portfolio/[slug]/page.tsx b/src/app/portfolio/[slug]/page.tsx
index c99fa3f..c392673 100644
--- a/src/app/portfolio/[slug]/page.tsx
+++ b/src/app/portfolio/[slug]/page.tsx
@@ -260,7 +260,8 @@ export default async function Page({
   // This is temp until we retrieve this data from the frontend
   // TODO: Update the objects to contains objective + any other required information
 
-  const portfolioId = params.slug;
+  // We explcitly cast the slug to a number since it will be a string
+  const portfolioId = Number(params.slug);
   const {
     name: portfolioName,
     budget,