diff --git a/desktop/panel/eval.ts b/desktop/panel/eval.ts
index 9d931fee6..ef74182e6 100644
--- a/desktop/panel/eval.ts
+++ b/desktop/panel/eval.ts
@@ -205,8 +205,13 @@ export const makeEvalHandler = (
       preview: preview(res.value),
       shape: s,
       value: res.returnValue ? res.value : null,
-      size: json.length,
-      arrayCount: s.kind === 'array' ? (res.value || []).length : null,
+      size: res.size === undefined ? json.length : res.size,
+      arrayCount:
+        res.arrayCount === undefined
+          ? s.kind === 'array'
+            ? (res.value || []).length
+            : null
+          : res.arrayCount,
       contentType: res.contentType || 'application/json',
     };
   },
diff --git a/desktop/panel/program.test.js b/desktop/panel/program.test.js
index 1732e6ad9..9a288e9f2 100644
--- a/desktop/panel/program.test.js
+++ b/desktop/panel/program.test.js
@@ -1,4 +1,5 @@
 const path = require('path');
+import { file as makeTmpFile } from 'tmp-promise';
 const { LANGUAGES } = require('../../shared/languages');
 const { getProjectResultsFile } = require('../store');
 const fs = require('fs');
@@ -7,6 +8,7 @@ const { updateProjectHandler } = require('../store');
 const { CODE_ROOT } = require('../constants');
 const { makeEvalHandler } = require('./eval');
 const { inPath, withSavedPanels } = require('./testutil');
+const { parsePartialJSONFile } = require('./program');
 
 const TESTS = [
   {
@@ -172,3 +174,47 @@ for (const t of TESTS) {
     }
   });
 }
+
+describe('parsePartialJSONFile', function parsePartialJSONFileTest() {
+  test('correctly fills out partial file', async function fillsOutPartial() {
+    const f = await makeTmpFile();
+    try {
+      const whole = '[{"foo": "bar"}, {"big": "bad"}]';
+      fs.writeFileSync(f.path, whole);
+      const { value, size } = parsePartialJSONFile(f.path, 3);
+      expect(size).toBe(whole.length);
+      expect(value).toStrictEqual([{ foo: 'bar' }]);
+    } finally {
+      f.cleanup();
+    }
+  });
+
+  test('handles open-close in string', async function handlesOpenCloseInString() {
+    for (const c of ['{', '}', '[', ']']) {
+      const f = await makeTmpFile();
+      try {
+        const whole = `[{"foo": "${c}bar"}, {"big": "bad"}]`;
+        fs.writeFileSync(f.path, whole);
+        const { value, size } = parsePartialJSONFile(f.path, 3);
+        expect(size).toBe(whole.length);
+        expect(value).toStrictEqual([{ foo: `${c}bar` }]);
+      } finally {
+        f.cleanup();
+      }
+    }
+  });
+
+  test('handles escaped quotes in string', async function handlesEscapedQuotesInString() {
+    const f = await makeTmpFile();
+    try {
+      const whole = `[{"foo":"bar\\" { "},{"big":"bad"}]`;
+      expect(JSON.stringify(JSON.parse(whole))).toEqual(whole);
+      fs.writeFileSync(f.path, whole);
+      const { value, size } = parsePartialJSONFile(f.path, 3);
+      expect(size).toBe(whole.length);
+      expect(value).toStrictEqual([{ foo: `bar" { ` }]);
+    } finally {
+      f.cleanup();
+    }
+  });
+});
diff --git a/desktop/panel/program.ts b/desktop/panel/program.ts
index 057d3ffdc..0c482da29 100644
--- a/desktop/panel/program.ts
+++ b/desktop/panel/program.ts
@@ -10,6 +10,103 @@ import { SETTINGS } from '../settings';
 import { getProjectResultsFile } from '../store';
 import { EvalHandlerExtra, EvalHandlerResponse, guardPanel } from './types';
 
+export function parsePartialJSONFile(file: string, maxBytesToRead: number) {
+  let fd: number;
+  try {
+    fd = fs.openSync(file, 'r');
+  } catch (e) {
+    throw new NoResultError();
+  }
+
+  const { size } = fs.statSync(file);
+
+  if (size < maxBytesToRead) {
+    const f = fs.readFileSync(file).toString();
+    const value = JSON.parse(f);
+    return {
+      size,
+      value,
+      arrayCount: f.charAt(0) === '[' ? value.length : null,
+    };
+  }
+
+  try {
+    let done = false;
+    let f = '';
+    const incomplete = [];
+    let inString = false;
+
+    while (!done) {
+      const bufferSize = 1024;
+      const b = Buffer.alloc(bufferSize);
+      const bytesRead = fs.readSync(fd, b);
+
+      // To be able to iterate over code points
+      let bs = Array.from(b.toString());
+      outer: for (let i = 0; i < bs.length; i++) {
+        const c = bs[i];
+        if (c !== '"' && inString) {
+          continue;
+        }
+
+        switch (c) {
+          case '"':
+            const previous =
+              i + bs.length === 0
+                ? ''
+                : i > 0
+                ? bs[i - 1]
+                : f.charAt(f.length - 1);
+            const isEscaped = previous === '\\';
+            if (!isEscaped) {
+              inString = !inString;
+            }
+            break;
+          case '{':
+          case '[':
+            incomplete.push(c);
+            break;
+          case ']':
+          case '}':
+            if (f.length + bufferSize >= maxBytesToRead) {
+              bs = bs.slice(0, i);
+              // Need to not count additional openings after this
+              done = true;
+              break outer;
+            }
+
+            // Otherwise, pop it
+            incomplete.pop();
+            break;
+        }
+      }
+
+      f += bs.join('');
+      if (bytesRead < bufferSize) {
+        break;
+      }
+    }
+
+    while (incomplete.length) {
+      if (incomplete.pop() === '{') {
+        f += '}';
+      } else {
+        f += ']';
+      }
+    }
+
+    const value = JSON.parse(f);
+
+    return {
+      size,
+      value,
+      arrayCount: f.charAt(0) === '[' ? 'More than ' + value.length : null,
+    };
+  } finally {
+    fs.closeSync(fd);
+  }
+}
+
 export async function evalProgram(
   project: ProjectState,
   panel: PanelInfo,
@@ -76,18 +173,17 @@ export async function evalProgram(
         throw new Error(stderr);
       }
 
-      let f: Buffer;
-      try {
-        f = fs.readFileSync(projectResultsFile + ppi.id);
-      } catch (e) {
-        throw new NoResultError();
-      }
-      const value = JSON.parse(f.toString());
+      const { size, value, arrayCount } = parsePartialJSONFile(
+        projectResultsFile + ppi.id,
+        100_000
+      );
 
       return {
         skipWrite: true,
         value,
         stdout: out,
+        size,
+        arrayCount,
       };
     } catch (e) {
       const resultsFileRE = new RegExp(
diff --git a/desktop/panel/types.ts b/desktop/panel/types.ts
index 38f77343a..2a0667426 100644
--- a/desktop/panel/types.ts
+++ b/desktop/panel/types.ts
@@ -7,6 +7,8 @@ export type EvalHandlerResponse = {
   stdout?: string;
   contentType?: string;
   value: any;
+  size?: any;
+  arrayCount?: any;
 };
 
 export type EvalHandlerExtra = {
diff --git a/shared/languages/javascript.ts b/shared/languages/javascript.ts
index b0a030a5e..ff6d9adbc 100644
--- a/shared/languages/javascript.ts
+++ b/shared/languages/javascript.ts
@@ -38,7 +38,21 @@ function DM_getPanel(i) {
 }
 function DM_setPanel(v) {
   const fs = require('fs');
-  fs.writeFileSync('${resultsFile + panelId}', JSON.stringify(v));
+  const fd = fs.openSync('${resultsFile + panelId}', 'w');
+  if (Array.isArray(v)) {
+    fs.writeSync(fd, '[');
+    for (let i = 0; i < v.length; i++) {
+      const row = v[i];
+      let rowJSON = JSON.stringify(row);
+      if (i < v.length - 1) {
+        rowJSON += ',';
+      }
+      fs.writeSync(fd, rowJSON);
+    }
+    fs.writeSync(fd, ']');
+  } else {
+    fs.writeSync(fd, JSON.stringify(v));
+  }
 }`;
 }
 
diff --git a/ui/app.test.jsx b/ui/app.test.jsx
index d455e615f..074c14953 100644
--- a/ui/app.test.jsx
+++ b/ui/app.test.jsx
@@ -96,7 +96,6 @@ test(
     for (let i = 0; i < connectors.length; i++) {
       const c = connectors.at(i);
       act(() => {
-        console.log(c.debug());
         c.find({
           'data-testid': 'show-hide-connector',
           icon: true,
diff --git a/ui/style.css b/ui/style.css
index fa2067b56..21769fe02 100644
--- a/ui/style.css
+++ b/ui/style.css
@@ -43,6 +43,7 @@ a:hover {
 
 .main-body {
   flex: 1;
+  overflow-y: auto;
 }
 
 header {
@@ -342,7 +343,6 @@ label.select select {
   border-bottom: 1px solid #ccc;
   background: white;
   width: 350px;
-  overflow-y: auto;
   background: #fbfbfb;
   padding: 15px;
 }
@@ -812,7 +812,7 @@ th {
 }
 
 tbody tr:nth-child(odd) {
-  background: #f9f0ff;
+  background: #f2f2f7;
 }
 
 .confirm-wrapper {
@@ -887,6 +887,10 @@ body.dark .connector--expanded {
 body.dark .button:hover {
   background: #383852;
 }
+
+body.dark tbody tr:nth-child(odd) {
+  background: #31314e;
+}
 /* End cssplus break */
 
 body.dark {