diff --git a/src-electron/db/query-session-notification.js b/src-electron/db/query-session-notification.js
index da05bcb9e5..ff5f58d2e9 100644
--- a/src-electron/db/query-session-notification.js
+++ b/src-electron/db/query-session-notification.js
@@ -164,13 +164,8 @@ async function searchNotificationByMessageAndDelete(db, sessionId, message) {
     [sessionId, message]
   )
   if (rows && rows.length > 0) {
-    let ids = rows.map((row) => row.NOTICE_ID)
-    let deleteResponses = []
-    for (let id of ids) {
-      let response = await deleteNotification(db, id)
-      deleteResponses.push(response)
-    }
-    return deleteResponses
+    const ids = rows.map((row) => row.NOTICE_ID)
+    return Promise.all(ids.map((id) => deleteNotification(db, id)))
   }
   return false
 }
@@ -212,9 +207,11 @@ async function setNotificationOnFeatureChange(db, sessionId, result) {
     outdatedWarningPatterns
   } = result
   if (disableChange) {
-    for (let message of warningMessage) {
-      await setWarningIfMessageNotExists(db, sessionId, message)
-    }
+    await Promise.all(
+      warningMessage.map((message) =>
+        setWarningIfMessageNotExists(db, sessionId, message)
+      )
+    )
   } else {
     await deleteNotificationWithPatterns(db, sessionId, outdatedWarningPatterns)
     if (displayWarning) {
@@ -288,13 +285,8 @@ async function deleteNotificationWithPatterns(db, sessionId, patterns) {
 
   let rows = await dbApi.dbAll(db, query, params)
   if (rows && rows.length > 0) {
-    let ids = rows.map((row) => row.NOTICE_ID)
-    let deleteResponses = []
-    for (let id of ids) {
-      let response = await deleteNotification(db, id)
-      deleteResponses.push(response)
-    }
-    return deleteResponses
+    const ids = rows.map((row) => row.NOTICE_ID)
+    return Promise.all(ids.map((id) => deleteNotification(db, id)))
   }
   return false
 }
diff --git a/src-electron/generator/generation-engine.js b/src-electron/generator/generation-engine.js
index b908a1d65e..0724715346 100644
--- a/src-electron/generator/generation-engine.js
+++ b/src-electron/generator/generation-engine.js
@@ -596,9 +596,13 @@ async function loadTemplates(
       templateData: []
     }
     if (genTemplatesJsonArray != null && genTemplatesJsonArray.length > 0) {
-      for (let jsonFile of genTemplatesJsonArray) {
-        if (jsonFile == null || jsonFile == '') continue
-        let ctx = await loadGenTemplatesJsonFile(db, jsonFile)
+      const filesToLoad = genTemplatesJsonArray.filter(
+        (f) => f != null && f !== ''
+      )
+      const loadResults = await Promise.all(
+        filesToLoad.map((jsonFile) => loadGenTemplatesJsonFile(db, jsonFile))
+      )
+      for (const ctx of loadResults) {
         if (ctx.error) {
           if (options.failOnLoadingError) globalCtx.error = ctx.error
         } else {
@@ -761,28 +765,32 @@ async function generateAllTemplates(
     hb: hb
   }
 
-  for (let pkg of packages) {
-    let outputOptions = await queryPackage.selectAllOptionsValues(
-      genResult.db,
-      pkg.id,
-      dbEnum.packageOptionCategory.outputOptions
-    )
-    outputOptions.forEach((opt) => {
-      if (opt.optionCode == 'iterator') {
-        pkg.iterator = opt.optionLabel
-      }
-    })
-    let generatorOptions = await queryPackage.selectAllOptionsValues(
-      genResult.db,
-      pkg.id,
-      dbEnum.packageOptionCategory.generator
-    )
-    generatorOptions.forEach((opt) => {
-      if (opt.optionCode == 'static') {
-        pkg.static = opt.optionLabel
-      }
+  await Promise.all(
+    packages.map(async (pkg) => {
+      const [outputOptions, generatorOptions] = await Promise.all([
+        queryPackage.selectAllOptionsValues(
+          genResult.db,
+          pkg.id,
+          dbEnum.packageOptionCategory.outputOptions
+        ),
+        queryPackage.selectAllOptionsValues(
+          genResult.db,
+          pkg.id,
+          dbEnum.packageOptionCategory.generator
+        )
+      ])
+      outputOptions.forEach((opt) => {
+        if (opt.optionCode == 'iterator') {
+          pkg.iterator = opt.optionLabel
+        }
+      })
+      generatorOptions.forEach((opt) => {
+        if (opt.optionCode == 'static') {
+          pkg.static = opt.optionLabel
+        }
+      })
     })
-  }
+  )
   // First extract overridePath if one exists, as we need to
   // pass it to the generation.
   packages.forEach((singlePkg) => {
diff --git a/src-electron/generator/helper-endpointconfig.js b/src-electron/generator/helper-endpointconfig.js
index 5e78bd0f89..c19f5d1beb 100644
--- a/src-electron/generator/helper-endpointconfig.js
+++ b/src-electron/generator/helper-endpointconfig.js
@@ -953,22 +953,30 @@ async function collectAttributes(
 
       c.attributes.sort(zclUtil.attributeComparator)
 
+      // Resolve all attribute default values in parallel, then process in order.
+      const attributeDefaultValues = await Promise.all(
+        c.attributes.map((a) =>
+          determineAttributeDefaultValue(
+            a.defaultValue,
+            a.type,
+            a.typeSize,
+            a.isNullable,
+            db,
+            sessionId
+          )
+        )
+      )
+
       // Go over all the attributes in the endpoint and add them to the list.
-      for (let a of c.attributes) {
+      for (let attrIdx = 0; attrIdx < c.attributes.length; attrIdx++) {
+        let a = c.attributes[attrIdx]
+        let attributeDefaultValue = attributeDefaultValues[attrIdx]
         // typeSize is the size of a buffer needed to hold the attribute, if
         // that's known.
         let typeSize = a.typeSize
         // defaultSize is the size of the attribute in the readonly defaults
         // store.
         let defaultSize = typeSize
-        let attributeDefaultValue = await determineAttributeDefaultValue(
-          a.defaultValue,
-          a.type,
-          typeSize,
-          a.isNullable,
-          db,
-          sessionId
-        )
         // Various types store the length of the actual content in bytes.
         // For those, we can size the default storage to be just big enough for
         // the actual default value.
diff --git a/src-electron/generator/matter/app/zap-templates/common/ClustersHelper.js b/src-electron/generator/matter/app/zap-templates/common/ClustersHelper.js
index 5faeb23e11..dba22fd918 100644
--- a/src-electron/generator/matter/app/zap-templates/common/ClustersHelper.js
+++ b/src-electron/generator/matter/app/zap-templates/common/ClustersHelper.js
@@ -111,20 +111,21 @@ async function loadEndpoints() {
 
   const endpoints = await queryEndpoint.selectAllEndpoints(db, sessionId);
 
-  // Selection is one by one since existing API does not seem to provide
-  // linkage between cluster and what endpoint it belongs to.
-  //
-  // TODO: there should be a better way
-  for (const endpoint of endpoints) {
-    const endpointClusters =
-      await queryEndpointType.selectAllClustersDetailsFromEndpointTypes(db, [
-        { endpointTypeId: endpoint.endpointTypeRef }
-      ]);
-    result.push({
-      ...endpoint,
-      clusters: endpointClusters.filter((c) => c.enabled == 1)
-    });
-  }
+  // Fetch cluster details per endpoint in parallel (API does not provide
+  // linkage between cluster and endpoint; one query per endpoint type).
+  const endpointResults = await Promise.all(
+    endpoints.map(async (endpoint) => {
+      const endpointClusters =
+        await queryEndpointType.selectAllClustersDetailsFromEndpointTypes(db, [
+          { endpointTypeId: endpoint.endpointTypeRef }
+        ]);
+      return {
+        ...endpoint,
+        clusters: endpointClusters.filter((c) => c.enabled == 1)
+      };
+    })
+  );
+  result.push(...endpointResults);
 
   return result;
 }
diff --git a/src-electron/generator/template-engine.js b/src-electron/generator/template-engine.js
index b0e0d137c1..edbfa8a1ba 100644
--- a/src-electron/generator/template-engine.js
+++ b/src-electron/generator/template-engine.js
@@ -118,22 +118,25 @@ async function produceIterativeContent(
     db,
     sessionId
   )
-  let res = []
-  for (let it of iterationArray) {
-    options.overrideKey = util.patternFormat(singleTemplatePkg.category, it)
-    options.initialContext = it
-    let r = await produceContent(
-      hb,
-      metaInfo,
-      db,
-      sessionId,
-      singleTemplatePkg,
-      genTemplateJsonPackage,
-      options
-    )
-    res.push(...r)
-  }
-  return res
+  let resultArrays = await Promise.all(
+    iterationArray.map((it) => {
+      const iterOptions = {
+        ...options,
+        overrideKey: util.patternFormat(singleTemplatePkg.category, it),
+        initialContext: it
+      }
+      return produceContent(
+        hb,
+        metaInfo,
+        db,
+        sessionId,
+        singleTemplatePkg,
+        genTemplateJsonPackage,
+        iterOptions
+      )
+    })
+  )
+  return resultArrays.flat()
 }
 
 /**
@@ -209,10 +212,11 @@ async function produceContent(
         )
       )
     ])
-    // Render deferred blocks
-    for (let deferredBlock of context.global.deferredBlocks) {
-      content += await deferredBlock(context)
-    }
+    // Render deferred blocks (parallel; order preserved by Promise.all)
+    const deferredParts = await Promise.all(
+      context.global.deferredBlocks.map((block) => block(context))
+    )
+    content += deferredParts.join('')
   } catch (error) {
     // Log the error and throw it
     notification.setNotification(
diff --git a/src-electron/main-process/startup.js b/src-electron/main-process/startup.js
index 715afe5378..e5cc6c7d7e 100644
--- a/src-electron/main-process/startup.js
+++ b/src-electron/main-process/startup.js
@@ -907,21 +907,22 @@ async function generateSingleFile(
   if (usedTemplatePackageIds.length === 0) {
     usedTemplatePackageIds = [templatePackageId]
   }
-  let genResults = []
-  for (let i = 0; i < usedTemplatePackageIds.length; i++) {
-    let genResult = await generatorEngine.generateAndWriteFiles(
-      db,
-      sessionId,
-      usedTemplatePackageIds[i],
-      output,
-      options
+  const genResults = await Promise.all(
+    usedTemplatePackageIds.map((templatePackageId) =>
+      generatorEngine.generateAndWriteFiles(
+        db,
+        sessionId,
+        templatePackageId,
+        output,
+        options
+      )
     )
-
+  )
+  for (const genResult of genResults) {
     if (genResult.hasErrors) {
       console.log(JSON.stringify(genResult.errors))
       throw new Error(`Generation failed: ${zapFile}`)
     }
-    genResults.push(genResult)
   }
 
   if (options.upgradeZapFile && isZapFileUpgradeNeeded) {