diff --git a/src/agents/definitions/implementation.yaml b/src/agents/definitions/implementation.yaml
index c8b8849e..0cbda959 100644
--- a/src/agents/definitions/implementation.yaml
+++ b/src/agents/definitions/implementation.yaml
@@ -60,7 +60,6 @@ backend:
     scm:
       enableStopHooks: true
       requiresPR: true
-  postConfigure: sequentialGadgetExecution
 
 
 hint: >-
diff --git a/src/agents/definitions/schema.ts b/src/agents/definitions/schema.ts
index abdcaf5d..36af1614 100644
--- a/src/agents/definitions/schema.ts
+++ b/src/agents/definitions/schema.ts
@@ -250,7 +250,6 @@ const BackendSchema = z.object({
 	requiresPR: z.boolean().optional(),
 	/** Category-scoped hook configuration */
 	hooks: HooksSchema.optional(),
-	postConfigure: z.enum(['sequentialGadgetExecution']).optional(),
 });
 
 const TrailingMessageSchema = z
diff --git a/src/agents/shared/builderFactory.ts b/src/agents/shared/builderFactory.ts
index 0229b466..89907ac0 100644
--- a/src/agents/shared/builderFactory.ts
+++ b/src/agents/shared/builderFactory.ts
@@ -36,8 +36,6 @@ export interface CreateBuilderOptions {
 	skipSessionState?: boolean;
 	/** Remaining card budget in USD — passed to llmist's withBudget() for in-flight enforcement */
 	remainingBudgetUsd?: number;
-	/** Post-configuration callback for agent-specific builder tweaks */
-	postConfigure?: (builder: BuilderType) => BuilderType;
 	/** Accumulator for per-call LLM metrics (for run tracking) */
 	llmCallAccumulator?: AccumulatedLlmCall[];
 	/** Run ID for real-time LLM call logging (resolved before builder creation) */
@@ -73,7 +71,6 @@ export async function createConfiguredBuilder(options: CreateBuilderOptions): Pr
 		progressMonitor,
 		skipSessionState,
 		remainingBudgetUsd,
-		postConfigure,
 	} = options;
 
 	// Initialize session state for gadgets (e.g., Finish checks PR requirement for implementation)
@@ -128,9 +125,7 @@ export async function createConfiguredBuilder(options: CreateBuilderOptions): Pr
 		}
 	}
 
-	if (postConfigure) {
-		builder = postConfigure(builder);
-	}
+	builder = builder.withGadgetExecutionMode('sequential');
 
 	return builder;
 }
diff --git a/src/backends/llmist/index.ts b/src/backends/llmist/index.ts
index 9363a4d5..25531996 100644
--- a/src/backends/llmist/index.ts
+++ b/src/backends/llmist/index.ts
@@ -3,7 +3,6 @@ import os from 'node:os';
 import { LLMist, type ModelSpec, createLogger } from 'llmist';
 
 import { createIntegrationChecker } from '../../agents/capabilities/index.js';
-import { resolveAgentDefinition } from '../../agents/definitions/index.js';
 import { type BuilderType, createConfiguredBuilder } from '../../agents/shared/builderFactory.js';
 import { injectSyntheticCall } from '../../agents/shared/syntheticCalls.js';
 import { runAgentLoop } from '../../agents/utils/agentLoop.js';
@@ -17,11 +16,6 @@ import { extractPRUrl } from '../../utils/prUrl.js';
 import { getAgentProfile } from '../agent-profiles.js';
 import type { AgentBackend, AgentBackendInput, AgentBackendResult } from '../types.js';
 
-/** Post-configure registry: maps YAML string references to builder transform functions */
-const POST_CONFIGURE_REGISTRY: Record<string, (builder: BuilderType) => BuilderType> = {
-	sequentialGadgetExecution: (b) => b.withGadgetExecutionMode('sequential'),
-};
-
 /**
  * llmist backend — executes agents using the llmist SDK.
  *
@@ -122,16 +116,6 @@ export class LlmistBackend implements AgentBackend {
 			progressMonitor: progressReporter as Parameters<
 				typeof createConfiguredBuilder
 			>[0]['progressMonitor'],
-			// Post-configure hook from YAML definition (e.g., sequentialGadgetExecution for implementation)
-			postConfigure: await (async () => {
-				try {
-					const def = await resolveAgentDefinition(agentType);
-					const hookName = def.backend.postConfigure;
-					return hookName ? POST_CONFIGURE_REGISTRY[hookName] : undefined;
-				} catch {
-					return undefined;
-				}
-			})(),
 		});
 
 		// Convert ContextInjection[] from the unified adapter into synthetic gadget calls.
diff --git a/tests/unit/agents/definitions/loader.test.ts b/tests/unit/agents/definitions/loader.test.ts
index 88653f21..7e1cd375 100644
--- a/tests/unit/agents/definitions/loader.test.ts
+++ b/tests/unit/agents/definitions/loader.test.ts
@@ -131,11 +131,6 @@ describe('YAML agent definitions loader', () => {
 	});
 
 	describe('definition content spot checks', () => {
-		it('implementation has postConfigure hook', () => {
-			const def = loadAgentDefinition('implementation');
-			expect(def.backend.postConfigure).toBe('sequentialGadgetExecution');
-		});
-
 		it('implementation has requiresPR flag in hooks.scm', () => {
 			const def = loadAgentDefinition('implementation');
 			expect(def.backend.hooks?.scm?.requiresPR).toBe(true);
@@ -265,7 +260,6 @@ describe('YAML agent definitions loader', () => {
 			expect(caps.isReadOnly).toBe(false);
 			expect(def.backend.hooks?.scm?.enableStopHooks).toBe(true);
 			expect(def.backend.needsGitHubToken).toBe(true);
-			expect(def.backend.postConfigure).toBe('sequentialGadgetExecution');
 		});
 
 		it('review agent is read-only', async () => {
diff --git a/tests/unit/agents/definitions/schema.test.ts b/tests/unit/agents/definitions/schema.test.ts
index 72f9df59..3847a89b 100644
--- a/tests/unit/agents/definitions/schema.test.ts
+++ b/tests/unit/agents/definitions/schema.test.ts
@@ -350,7 +350,6 @@ describe('AgentDefinitionSchema', () => {
 			backend: {
 				...validDefinition.backend,
 				blockGitPush: false,
-				postConfigure: 'sequentialGadgetExecution',
 			},
 			trailingMessage: {
 				includeDiagnostics: true,
@@ -388,24 +387,6 @@ describe('AgentDefinitionSchema', () => {
 		}
 	});
 
-	it('rejects invalid postConfigure hook names', () => {
-		const bad = {
-			...validDefinition,
-			backend: { ...validDefinition.backend, postConfigure: 'nonexistentHook' },
-		};
-		const result = AgentDefinitionSchema.safeParse(bad);
-		expect(result.success).toBe(false);
-	});
-
-	it('accepts valid postConfigure hook name', () => {
-		const good = {
-			...validDefinition,
-			backend: { ...validDefinition.backend, postConfigure: 'sequentialGadgetExecution' },
-		};
-		const result = AgentDefinitionSchema.safeParse(good);
-		expect(result.success).toBe(true);
-	});
-
 	it('accepts requiresPR boolean', () => {
 		const good = {
 			...validDefinition,
diff --git a/tests/unit/agents/shared/builderFactory.test.ts b/tests/unit/agents/shared/builderFactory.test.ts
index 914ca02a..a27aff19 100644
--- a/tests/unit/agents/shared/builderFactory.test.ts
+++ b/tests/unit/agents/shared/builderFactory.test.ts
@@ -44,6 +44,7 @@ const mockBuilderInstance = {
 	withGadgets: vi.fn(),
 	withMaxGadgetsPerResponse: vi.fn(),
 	withBudget: vi.fn(),
+	withGadgetExecutionMode: vi.fn(),
 };
 
 // Each method returns the builder for chaining
@@ -232,22 +233,10 @@ describe('createConfiguredBuilder', () => {
 		await expect(createConfiguredBuilder(options)).rejects.toThrow('Unexpected budget error');
 	});
 
-	it('calls postConfigure callback when provided', async () => {
-		const customBuilder = { ...mockBuilderInstance, custom: true };
-		const postConfigure = vi.fn().mockReturnValue(customBuilder);
-		const options = createBaseOptions({ postConfigure });
-
-		const result = await createConfiguredBuilder(options);
-
-		expect(postConfigure).toHaveBeenCalled();
-		expect(result).toBe(customBuilder);
-	});
-
-	it('does not call postConfigure when not provided', async () => {
-		const options = createBaseOptions({ postConfigure: undefined });
-
-		// Should not throw and returns builder
-		await expect(createConfiguredBuilder(options)).resolves.not.toThrow();
+	it('calls withGadgetExecutionMode with sequential unconditionally', async () => {
+		const options = createBaseOptions();
+		await createConfiguredBuilder(options);
+		expect(mockBuilderInstance.withGadgetExecutionMode).toHaveBeenCalledWith('sequential');
 	});
 
 	it('returns a builder with max gadgets per response set', async () => {
diff --git a/web/src/components/settings/agent-definition-editor.tsx b/web/src/components/settings/agent-definition-editor.tsx
index aa8de8eb..62ea8fd1 100644
--- a/web/src/components/settings/agent-definition-editor.tsx
+++ b/web/src/components/settings/agent-definition-editor.tsx
@@ -6,13 +6,6 @@ import {
 import { Badge } from '@/components/ui/badge.js';
 import { Input } from '@/components/ui/input.js';
 import { Label } from '@/components/ui/label.js';
-import {
-	Select,
-	SelectContent,
-	SelectItem,
-	SelectTrigger,
-	SelectValue,
-} from '@/components/ui/select.js';
 import { Tabs, TabsContent, TabsList, TabsTrigger } from '@/components/ui/tabs.js';
 import { Textarea } from '@/components/ui/textarea.js';
 import {
@@ -449,27 +442,6 @@ function BackendSection({
 					description="Agent receives GitHub token for API access. Required for PR creation and code reviews."
 				/>
 			</div>
-
-			<div className="grid grid-cols-1 gap-3">
-				<div className="space-y-1">
-					<div className="flex items-center gap-1.5">
-						<Label>Post-Configure Hook</Label>
-						<InfoTooltip text="Hook run after builder configuration. 'sequentialGadgetExecution' forces serial gadget execution." />
-					</div>
-					<Select
-						value={def.backend.postConfigure ?? '_none'}
-						onValueChange={(v) => setBackend('postConfigure', v === '_none' ? undefined : v)}
-					>
-						<SelectTrigger className="w-full">
-							<SelectValue placeholder="None" />
-						</SelectTrigger>
-						<SelectContent>
-							<SelectItem value="_none">None</SelectItem>
-							<SelectItem value="sequentialGadgetExecution">sequentialGadgetExecution</SelectItem>
-						</SelectContent>
-					</Select>
-				</div>
-			</div>
 		</section>
 	);
 }