diff --git a/apps/worker/src/tasks/grant-author-achievements/processor.ts b/apps/worker/src/tasks/grant-author-achievements/processor.ts
index aed8c769..059819b8 100644
--- a/apps/worker/src/tasks/grant-author-achievements/processor.ts
+++ b/apps/worker/src/tasks/grant-author-achievements/processor.ts
@@ -31,7 +31,7 @@ export default createProcessor(Tasks.GRANT_AUTHOR_ACHIEVEMENTS, async (job) => {
 		socials?: Record<string, string>;
 	};
 	const roles = meta.roles ?? [];
-	const githubLogin = meta.socials?.github;
+	const githubLogin = meta.socials?.["github"];
 
 	// ── Content stats ─────────────────────────────────────────────────────────
 
diff --git a/apps/worker/src/tasks/sync-collection/processor.ts b/apps/worker/src/tasks/sync-collection/processor.ts
index d90c15ad..620b8c91 100644
--- a/apps/worker/src/tasks/sync-collection/processor.ts
+++ b/apps/worker/src/tasks/sync-collection/processor.ts
@@ -188,6 +188,8 @@ export default createProcessor(
 					.values(result)
 					.returning({ id: collections.id });
 
+				if (!collectionRecord) throw new Error("undefined collectionRecord");
+
 				// Delete existing author associations for this collection
 				await tx
 					.delete(collectionAuthors)
diff --git a/apps/worker/src/tasks/sync-post/processor.ts b/apps/worker/src/tasks/sync-post/processor.ts
index 45f7b3a9..484bfcb3 100644
--- a/apps/worker/src/tasks/sync-post/processor.ts
+++ b/apps/worker/src/tasks/sync-post/processor.ts
@@ -177,6 +177,7 @@ export default createProcessor(Tasks.SYNC_POST, async (job, { signal }) => {
 						.insert(postGroups)
 						.values({})
 						.returning({ id: postGroups.id });
+					if (!newGroup) throw new Error("undefined newGroup");
 					groupId = newGroup.id;
 				}
 			}
@@ -217,6 +218,8 @@ export default createProcessor(Tasks.SYNC_POST, async (job, { signal }) => {
 				.values(postValues)
 				.returning({ id: posts.id });
 
+			if (!postRecord) throw new Error("undefined postRecord");
+
 			const authorSlugs = new Set<string>([author, ...(parsed.authors ?? [])]);
 			authorSlugs.forEach((authorSlug) => affectedAuthorSlugs.add(authorSlug));
 
diff --git a/apps/worker/src/tasks/url-metadata/data-providers/youtube.ts b/apps/worker/src/tasks/url-metadata/data-providers/youtube.ts
index 60ee9dc6..1362b992 100644
--- a/apps/worker/src/tasks/url-metadata/data-providers/youtube.ts
+++ b/apps/worker/src/tasks/url-metadata/data-providers/youtube.ts
@@ -25,7 +25,7 @@ export async function getYouTubeOEmbedDataFromUrl(
 	signal: AbortSignal,
 ): Promise<YouTubeOEmbedResponse | null> {
 	const splitPath = url.pathname.split("/").filter(Boolean);
-	let videoId: string;
+	let videoId: string | undefined;
 	if (url.host === youtubeShortHost) {
 		videoId = splitPath[0];
 	} else if (splitPath[0] === "watch") {
@@ -40,10 +40,9 @@ export async function getYouTubeOEmbedDataFromUrl(
 		// https://www.youtube.com/shorts/Fdbha07mFzo
 	} else if (splitPath[0] === "shorts") {
 		videoId = splitPath[1];
-	} else {
-		return null;
 	}
 
+	if (!videoId) return null;
 	const youtubeUrl = `https://www.youtube.com/watch?v=${videoId}`;
 
 	return await fetchAsBot({
diff --git a/apps/worker/src/tasks/url-metadata/getEmbedDataFromGist.ts b/apps/worker/src/tasks/url-metadata/getEmbedDataFromGist.ts
index 91c020f2..abf86540 100644
--- a/apps/worker/src/tasks/url-metadata/getEmbedDataFromGist.ts
+++ b/apps/worker/src/tasks/url-metadata/getEmbedDataFromGist.ts
@@ -17,15 +17,13 @@ export async function getEmbedDataFromGist(
 	inputUrl: URL,
 	signal: AbortSignal,
 ): Promise<EmbedData> {
-	let error = false;
-
 	// https://gist.github.com/crutchcorn/36fe5553219c05ea38bacf1c7396085b
 	const gistPathParts = inputUrl.pathname.split("/").filter(Boolean);
 	const githubUsername = gistPathParts[0];
 	const gistId = gistPathParts[1];
 	if (!githubUsername || !gistId) {
 		console.error(`Invalid gist URL: ${inputUrl}`);
-		error = true;
+		return { error: true };
 	}
 
 	const data = await createAppClient()
@@ -114,6 +112,6 @@ export async function getEmbedDataFromGist(
 
 	return {
 		gistId,
-		error,
+		error: false,
 	};
 }
diff --git a/apps/worker/src/tasks/url-metadata/getEmbedDataFromVideo.ts b/apps/worker/src/tasks/url-metadata/getEmbedDataFromVideo.ts
index 1b80186c..ac9e7717 100644
--- a/apps/worker/src/tasks/url-metadata/getEmbedDataFromVideo.ts
+++ b/apps/worker/src/tasks/url-metadata/getEmbedDataFromVideo.ts
@@ -54,9 +54,9 @@ export async function getEmbedDataFromVideo(
 	let embedHeight: number | undefined = undefined;
 	if (videoData?.html) {
 		const attributes = getIFrameAttributes(videoData.html);
-		if (attributes.src) embedSrc = String(attributes.src);
-		const width = Number(attributes.width);
-		const height = Number(attributes.height);
+		if (attributes["src"]) embedSrc = String(attributes["src"]);
+		const width = Number(attributes["width"]);
+		const height = Number(attributes["height"]);
 		if (isFinite(width)) embedWidth = width;
 		if (isFinite(height)) embedHeight = height;
 	}
diff --git a/apps/worker/src/tasks/url-metadata/utils/fetchPageHtml.ts b/apps/worker/src/tasks/url-metadata/utils/fetchPageHtml.ts
index f7e97e51..dc8fd68a 100644
--- a/apps/worker/src/tasks/url-metadata/utils/fetchPageHtml.ts
+++ b/apps/worker/src/tasks/url-metadata/utils/fetchPageHtml.ts
@@ -30,9 +30,11 @@ export async function getOpenGraphImages(
 	if (!headNode) return results;
 
 	visit(headNode, { type: "element", tagName: "meta" }, (e: Element) => {
-		if (["twitter:image", "og:image"].includes(String(e.properties.property))) {
+		if (
+			["twitter:image", "og:image"].includes(String(e.properties["property"]))
+		) {
 			try {
-				const url = new URL(String(e.properties.content), baseUrl);
+				const url = new URL(String(e.properties["content"]), baseUrl);
 				results.push(url);
 			} catch (_e) {
 				// ignore
diff --git a/apps/worker/src/tasks/url-metadata/utils/fetchPageIcons.ts b/apps/worker/src/tasks/url-metadata/utils/fetchPageIcons.ts
index 4ac4748c..159cf795 100644
--- a/apps/worker/src/tasks/url-metadata/utils/fetchPageIcons.ts
+++ b/apps/worker/src/tasks/url-metadata/utils/fetchPageIcons.ts
@@ -16,8 +16,8 @@ export async function fetchPageIcons(
 
 	// Try getting icon from link tags first
 	visit(headNode, { type: "element", tagName: "link" }, (node: Element) => {
-		const rel = String(node.properties?.rel ?? "");
-		const href = String(node.properties?.href ?? "");
+		const rel = String(node.properties?.["rel"] ?? "");
+		const href = String(node.properties?.["href"] ?? "");
 		if (!rel.includes("icon")) return;
 
 		try {
@@ -34,11 +34,11 @@ export async function fetchPageIcons(
 		(node) =>
 			isElement(node) &&
 			node.tagName === "link" &&
-			String(node.properties.rel).includes("manifest"),
+			String(node.properties["rel"]).includes("manifest"),
 	);
 
-	if (manifestLink?.properties?.href) {
-		const manifestUrl = new URL(String(manifestLink.properties.href), src);
+	if (manifestLink?.properties?.["href"]) {
+		const manifestUrl = new URL(String(manifestLink.properties["href"]), src);
 		const manifest = await fetchAsBot({
 			url: manifestUrl,
 			method: "GET",
diff --git a/apps/worker/src/tasks/url-metadata/utils/processImage.ts b/apps/worker/src/tasks/url-metadata/utils/processImage.ts
index bfd88350..ffb594fb 100644
--- a/apps/worker/src/tasks/url-metadata/utils/processImage.ts
+++ b/apps/worker/src/tasks/url-metadata/utils/processImage.ts
@@ -297,4 +297,5 @@ export async function processImages(
 			return result;
 		}
 	}
+	return undefined;
 }
diff --git a/apps/worker/src/utils/extractLocale.ts b/apps/worker/src/utils/extractLocale.ts
index c44a2c3e..a5870703 100644
--- a/apps/worker/src/utils/extractLocale.ts
+++ b/apps/worker/src/utils/extractLocale.ts
@@ -1,4 +1,4 @@
 export function extractLocale(filename: string): string {
 	const match = filename.match(/index\.([a-z]+)\.md$/);
-	return match ? match[1] : "en";
+	return match?.[1] ?? "en";
 }
diff --git a/packages/bullmq/src/tasks/delete-s3-object.test.ts b/packages/bullmq/src/tasks/delete-s3-object.test.ts
index f5e33aa8..d7c394d0 100644
--- a/packages/bullmq/src/tasks/delete-s3-object.test.ts
+++ b/packages/bullmq/src/tasks/delete-s3-object.test.ts
@@ -10,7 +10,7 @@ afterEach(() => {
 });
 
 function jobIdFromCall(callIndex: number): string {
-	return vi.mocked(createJob).mock.calls[callIndex][1] as string;
+	return vi.mocked(createJob).mock.calls[callIndex]?.[1] as string;
 }
 
 test("reuses the same job id when lastModified is unchanged across calls", async () => {
diff --git a/packages/github-api/src/getAuthorGitHubStats.ts b/packages/github-api/src/getAuthorGitHubStats.ts
index a9b01e5d..bc43e516 100644
--- a/packages/github-api/src/getAuthorGitHubStats.ts
+++ b/packages/github-api/src/getAuthorGitHubStats.ts
@@ -52,12 +52,12 @@ export async function getAuthorGitHubStats(
 	client: Octokit,
 	githubLogin: string,
 ): Promise<AuthorGitHubStats | undefined> {
-	const userResult = (await client.graphql<Record<string, { id: string }>>(
+	const userResult = await client.graphql<Record<string, { id: string }>>(
 		`query($login: String!) { user(login: $login) { id } }`,
 		{ login: githubLogin },
-	)) as Record<string, { id: string }>;
+	);
 
-	const userId = userResult?.user?.id;
+	const userId = userResult?.["user"]?.id;
 	if (!userId) return undefined;
 
 	const response = await client.graphql<StatsResponse>(statsQuery, {
diff --git a/packages/post-images/src/fetch-post-data.ts b/packages/post-images/src/fetch-post-data.ts
index b8f229c2..0b30ee85 100644
--- a/packages/post-images/src/fetch-post-data.ts
+++ b/packages/post-images/src/fetch-post-data.ts
@@ -137,7 +137,8 @@ export async function fetchPostData(
 		.then((json) => Value.Parse(TagsInfo, json));
 	const tags = (indexInfo.tags ?? [])
 		.map((tagId) => tagsJson[tagId])
-		.filter((tag) => tag?.emoji || (tag?.image && tag.shownWithBranding))
+		.filter((tag) => !!tag)
+		.filter((tag) => tag.emoji || (tag.image && tag.shownWithBranding))
 		.map((tag) => ({
 			displayName: tag.displayName,
 			emoji: tag.emoji,
diff --git a/tsconfig.json b/tsconfig.json
index 83b5b244..b94ae831 100644
--- a/tsconfig.json
+++ b/tsconfig.json
@@ -14,6 +14,8 @@
 		"esModuleInterop": true,
 		"noImplicitOverride": true,
 		"noFallthroughCasesInSwitch": true,
+		"noPropertyAccessFromIndexSignature": true,
+		"noUncheckedIndexedAccess": true,
 		"forceConsistentCasingInFileNames": true,
 		"allowJs": true
 	},