diff --git a/packages/code-analyzer-core/test/utils.test.ts b/packages/code-analyzer-core/test/utils.test.ts
index 0dd5cde7..9ee4bef2 100644
--- a/packages/code-analyzer-core/test/utils.test.ts
+++ b/packages/code-analyzer-core/test/utils.test.ts
@@ -1,4 +1,7 @@
-import {deepEquals} from "../src/utils";
+import {deepEquals, RealFileSystem, TempFolder} from "../src/utils";
+import * as fs from "node:fs";
+import * as os from "node:os";
+import * as path from "node:path";
 
 describe('deepEquals function tests', () => {
     describe('primitive type comparison tests', () => {
@@ -151,4 +154,30 @@ describe('deepEquals function tests', () => {
             expect(deepEquals(obj1, obj2)).toBe(false);
         });
     });
+});
+
+describe('file system and temp folder utilities', () => {
+    it('RealFileSystem.rmSync removes a directory recursively (covers rmSync)', () => {
+        const realFs = new RealFileSystem();
+        const dir = fs.mkdtempSync(path.join(os.tmpdir(), 'ca-core-rmSync-'));
+        const nested = path.join(dir, 'nested');
+        fs.mkdirSync(nested);
+        fs.writeFileSync(path.join(nested, 'file.txt'), 'x');
+        expect(fs.existsSync(dir)).toBe(true);
+
+        realFs.rmSync(dir, {recursive: true, force: true});
+        expect(fs.existsSync(dir)).toBe(false);
+    });
+
+    it('TempFolder.removeSyncIfNotKept removes root when not marked to keep (covers removeSyncIfNotKept)', async () => {
+        const temp = new TempFolder(); // uses RealFileSystem internally
+        const subPath = await temp.getPath('sub');
+        const root = path.dirname(subPath);
+        fs.mkdirSync(subPath, {recursive: true});
+        fs.writeFileSync(path.join(subPath, 'a.txt'), 'content');
+        expect(fs.existsSync(root)).toBe(true);
+
+        temp.removeSyncIfNotKept();
+        expect(fs.existsSync(root)).toBe(false);
+    });
 });
\ No newline at end of file
diff --git a/packages/code-analyzer-eslint-engine/test/perf-eslint-run.test.ts b/packages/code-analyzer-eslint-engine/test/perf-eslint-run.test.ts
new file mode 100644
index 00000000..75f63c88
--- /dev/null
+++ b/packages/code-analyzer-eslint-engine/test/perf-eslint-run.test.ts
@@ -0,0 +1,92 @@
+import {Engine, RuleDescription, Workspace} from "@salesforce/code-analyzer-engine-api";
+import {ESLintEnginePlugin} from "../src";
+import {DEFAULT_CONFIG, ESLintEngineConfig} from "../src/config";
+import {createDescribeOptions, createRunOptions} from "./test-helpers";
+
+/**
+ * One-off performance probe for running ESLint rules (runRules).
+ *
+ * What this test does:
+ * - Instantiates the ESLint engine with the current base configuration.
+ * - Discovers rules (describeRules), then selects a subset to run (e.g., Recommended).
+ * - Runs the engine against the provided workspace (PERF_WS must be set).
+ * - Samples Node's resident set size (RSS) and prints a JSON summary:
+ *     {
+ *       "files_scanned": <unique files that produced violations>,
+ *       "rules_run": <number of rules executed>,
+ *       "run_ms": <wall time in milliseconds for runRules>,
+ *       "peak_rss_mb": <approximate peak memory (MB) observed during the run>,
+ *       "violations": <total violations found>
+ *     }
+ *
+ * How to run (skipped by default; opt-in with env var):
+ *   ESLINT_ENGINE_PERF_RUN=true PERF_WS="/absolute/path/to/project" PERF_DISCOVER=true \
+ *   npm run test-typescript -- packages/code-analyzer-eslint-engine/test/perf-eslint-run.test.ts
+ *
+ * Optional env vars:
+ * - PERF_RULES_LIMIT=200  → cap the number of rules to run (keeps runtime stable)
+ * - PERF_DISCOVER=true    → let ESLint auto-discover configs from PERF_WS (sets config_root to PERF_WS)
+ * - You can toggle:
+ *     // disable_react_base_config: true,
+ *     // disable_typescript_base_config: true,
+ *   in the config below to attribute parser/plugin costs.
+ */
+const RUN = process.env.ESLINT_ENGINE_PERF_RUN === 'true';
+(RUN ? describe : describe.skip)('ESLint engine perf (runRules one-off)', () => {
+    it('measures runRules wall time and peak RSS', async () => {
+        const cfg: ESLintEngineConfig = {
+            ...DEFAULT_CONFIG,
+            // Toggle to isolate costs if desired:
+            disable_react_base_config: false,
+            disable_typescript_base_config: true,
+            config_root: __dirname,
+            auto_discover_eslint_config: process.env.PERF_DISCOVER === 'true',
+        };
+
+        const wsPath = process.env.PERF_WS;
+        if (!wsPath) {
+            throw new Error('PERF_WS env var must be set to an absolute path for runRules perf test.');
+        }
+        const ws: Workspace = new Workspace('perf', [wsPath]);
+        if (process.env.PERF_DISCOVER === 'true') {
+            cfg.config_root = wsPath;
+        }
+
+        const engine: Engine = await new ESLintEnginePlugin().createEngine('eslint', cfg);
+
+        // Discover and select rules to run (Recommended by default), with an optional cap.
+        const discovered: RuleDescription[] = await engine.describeRules(createDescribeOptions(ws));
+        const rulesToRun: string[] = discovered
+            .filter(r => r.tags.includes('Recommended'))
+            .slice(0, Number(process.env.PERF_RULES_LIMIT) || 200)
+            .map(r => r.name);
+
+        const peak = {rss: 0};
+        const sampler = setInterval(() => {
+            const m = process.memoryUsage();
+            if (m.rss > peak.rss) peak.rss = m.rss;
+        }, 50);
+
+        const mem0 = process.memoryUsage().rss;
+        const t0 = performance.now();
+        const results = await engine.runRules(rulesToRun, createRunOptions(ws));
+        const t1 = performance.now();
+        const mem1 = process.memoryUsage().rss;
+        clearInterval(sampler);
+
+        // Calculate files that produced violations (as a proxy for scanned footprint).
+        const filesScanned = Array.from(new Set(results.violations.map(v => v.codeLocations[0].file))).length;
+
+        // eslint-disable-next-line no-console
+        console.log(JSON.stringify({
+            files_scanned: filesScanned,
+            rules_run: rulesToRun.length,
+            run_ms: Math.round(t1 - t0),
+            peak_rss_mb: Math.round(Math.max(peak.rss, mem0, mem1) / (1024 * 1024)),
+            violations: results.violations.length
+        }, null, 2));
+
+        expect(rulesToRun.length).toBeGreaterThan(0);
+    });
+});
+
diff --git a/packages/code-analyzer-eslint-engine/test/perf-eslint.test.ts b/packages/code-analyzer-eslint-engine/test/perf-eslint.test.ts
new file mode 100644
index 00000000..a46c6578
--- /dev/null
+++ b/packages/code-analyzer-eslint-engine/test/perf-eslint.test.ts
@@ -0,0 +1,90 @@
+import {Engine, RuleDescription, Workspace} from "@salesforce/code-analyzer-engine-api";
+import {ESLintEnginePlugin} from "../src";
+import {DEFAULT_CONFIG, ESLintEngineConfig} from "../src/config";
+import {createDescribeOptions} from "./test-helpers";
+import * as path from "node:path";
+
+/**
+ * One-off performance probe for the ESLint engine.
+ *
+ * What this test does:
+ * - Instantiates the ESLint engine with the current base configuration.
+ * - Calls engine.describeRules(), which exercises rule discovery (parsing configs, resolving plugins, building rule lists).
+ * - Samples Node's resident set size (RSS) periodically to estimate the peak memory use during describeRules().
+ * - Emits a single JSON object to stdout with:
+ *     {
+ *       "rule_count": <number of rules discovered>,
+ *       "describe_ms": <wall time in milliseconds for describeRules>,
+ *       "peak_rss_mb": <approximate peak memory (MB) observed during the call>
+ *     }
+ *
+ * How to run (skipped by default; opt-in with env var):
+ *   ESLINT_ENGINE_PERF=true npm run test-typescript -- packages/code-analyzer-eslint-engine/test/perf-eslint.test.ts
+ * 
+ * ESLINT_ENGINE_PERF=true PERF_WS="/Users/arun.tyagi/projects/dreamhouse-sfdx" PERF_DISCOVER=true \
+ * npm run test-typescript -- packages/code-analyzer-eslint-engine/test/perf-eslint.test.ts
+ *
+ * What to look for:
+ * - describe_ms: Use this to compare wall-time across changes. Lower is better.
+ * - peak_rss_mb: Track memory impact/regressions (e.g., when enabling additional parsers/plugins).
+ * - rule_count: Sanity check that you are comparing like-for-like runs (similar rule surface).
+ *
+ * How to isolate parser/plugin costs:
+ * - Set disable_react_base_config: true  → measure baseline without React rules/plugins.
+ * - Set disable_typescript_base_config: true → measure without the TypeScript parser/rules.
+ *   Run the test multiple times, toggling these flags, and compare the outputs.
+ *
+ * Notes:
+ * - This is a coarse probe (RSS sampling every 50ms). For deeper analysis, also try:
+ *     node --cpu-prof --heap-prof ./node_modules/.bin/jest packages/code-analyzer-eslint-engine/test/perf-eslint.test.ts
+ *   and inspect the generated profiles in Chrome DevTools.
+ */
+const RUN = process.env.ESLINT_ENGINE_PERF === 'true';
+(RUN ? describe : describe.skip)('ESLint engine perf (one-off)', () => {
+    it('measures describeRules wall time and peak RSS', async () => {
+        const config: ESLintEngineConfig = {
+            ...DEFAULT_CONFIG,
+            // Toggle these to isolate costs:
+            // disable_react_base_config: true,
+            // disable_typescript_base_config: true,
+            config_root: __dirname
+        };
+
+        // If a workspace path is provided (PERF_WS), analyze that project.
+        // Optionally allow ESLint to auto-discover configs from that project (PERF_DISCOVER=true).
+        const wsPath = process.env.PERF_WS;
+        const ws: Workspace | undefined = wsPath ? new Workspace('perf', [wsPath]) : undefined;
+        if (wsPath && process.env.PERF_DISCOVER === 'true') {
+            (config as ESLintEngineConfig).auto_discover_eslint_config = true;
+            (config as ESLintEngineConfig).config_root = wsPath;
+        }
+
+        // Create engine with the chosen config flags
+        const engine: Engine = await new ESLintEnginePlugin().createEngine('eslint', config);
+
+        // Track peak RSS during the measured operation with a light-weight sampler.
+        const peak = { rss: 0 };
+        const sampler = setInterval(() => {
+            const m = process.memoryUsage();
+            if (m.rss > peak.rss) peak.rss = m.rss;
+        }, 50);
+
+        // Measure wall time of describeRules (rule discovery).
+        const mem0 = process.memoryUsage().rss;
+        const t0 = performance.now();
+        const rules: RuleDescription[] = await engine.describeRules(createDescribeOptions(ws));
+        const t1 = performance.now();
+        const mem1 = process.memoryUsage().rss;
+        clearInterval(sampler);
+
+        // eslint-disable-next-line no-console
+        console.log(JSON.stringify({
+            rule_count: rules.length,
+            describe_ms: Math.round(t1 - t0),
+            peak_rss_mb: Math.round(Math.max(peak.rss, mem0, mem1) / (1024 * 1024))
+        }, null, 2));
+
+        expect(rules.length).toBeGreaterThan(0);
+    });
+});
+
diff --git a/packages/code-analyzer-eslint-engine/test/utils.test.ts b/packages/code-analyzer-eslint-engine/test/utils.test.ts
index 40200017..6745146e 100644
--- a/packages/code-analyzer-eslint-engine/test/utils.test.ts
+++ b/packages/code-analyzer-eslint-engine/test/utils.test.ts
@@ -114,3 +114,72 @@ describe('Tests for the makeStringifiable utility function', () => {
         expect(makeStringifiable(obj)).toEqual({"date": {}, "regex": {}});
     });
 });
+
+describe('utils: makeUnique deduplication and makeStringifiable serialization', () => {
+    describe('makeUnique removes duplicates and preserves order', () => {
+        it('removes duplicates while preserving order', () => {
+            expect(makeUnique(['a','b','a','c','b','d'])).toEqual(['a','b','c','d']);
+            expect(makeUnique([])).toEqual([]);
+        });
+    });
+
+    describe('makeStringifiable handles edge cases and tracks paths', () => {
+        it('passes through primitives', () => {
+            expect(makeStringifiable('str')).toBe('str');
+            expect(makeStringifiable(42)).toBe(42);
+            expect(makeStringifiable(true)).toBe(true);
+            expect(makeStringifiable(null)).toBe(null);
+        });
+
+        it('stringifies functions and symbols/bigints safely', () => {
+            expect(makeStringifiable(() => 1)).toBe('[Function]');
+            // BigInt and Symbol should stringify to String(value)
+            // Using toString form because equality to Symbol(...) is not supported
+            expect(makeStringifiable(BigInt(10))).toBe('10');
+            const s = Symbol('x');
+            expect(makeStringifiable(s)).toBe(String(s));
+        });
+
+        it('handles arrays with self references', () => {
+            const a: unknown[] = ['x'];
+            a.push(a); // self reference
+            const res = makeStringifiable(a) as unknown[];
+            expect(res[0]).toBe('x');
+            // second element becomes a marker with the first path where it was seen
+            expect(typeof res[1]).toBe('string');
+            expect((res[1] as string)).toContain('[Exact same array as: <val>'); // path marker
+        });
+
+        it('handles objects with self references', () => {
+            const o: Record<string, unknown> = {a: 1};
+            o.self = o; // cycle
+            const res = makeStringifiable(o) as Record<string, unknown>;
+            expect(res.a).toBe(1);
+            expect(typeof res.self).toBe('string');
+            expect((res.self as string)).toContain('[Exact same object as: <val>'); // path marker
+        });
+
+        it('marks unserializable property access with placeholder', () => {
+            const o = Object.create(null) as { ok: number; bad: unknown };
+            Object.defineProperty(o, 'ok', { value: 1, enumerable: true });
+            Object.defineProperty(o, 'bad', {
+                enumerable: true,
+                get() { throw new Error('boom'); }
+            });
+            const res = makeStringifiable(o) as Record<string, unknown>;
+            expect(res.ok).toBe(1);
+            expect(res.bad).toBe('[Unserializable]');
+        });
+
+        it('applies replacer with correct path propagation', () => {
+            const paths: string[] = [];
+            const v = { foo: { bar: [1,2] } };
+            const out = makeStringifiable(v, (_val, p) => { paths.push(p); return _val; });
+            expect(paths).toEqual(expect.arrayContaining([
+                '<val>', '<val>.foo', '<val>.foo.bar', '<val>.foo.bar[0]', '<val>.foo.bar[1]'
+            ]));
+            // structure preserved
+            expect((out as any).foo.bar[0]).toBe(1);
+        });
+    });
+});