diff --git a/backend/index.js b/backend/index.js
index 89b7737..e095296 100644
--- a/backend/index.js
+++ b/backend/index.js
@@ -199,6 +199,10 @@ app.post('/api/data', authenticateAPIKey, async (req, res) => {
     })();
 });
 
+// In-memory Waiting Room for WhatsApp Marketing
+const waitingRoom = {};
+const N8N_WHATSAPP_TRIGGER_URL = process.env.N8N_WHATSAPP_TRIGGER_URL || 'http://localhost:5678/webhook/whatsapp';
+
 // POST stock (for n8n)
 app.post('/api/stock', authenticateAPIKey, async (req, res) => {
     res.status(201).json({ message: 'Stock data received, processing in background' });
@@ -225,13 +229,91 @@ app.post('/api/stock', authenticateAPIKey, async (req, res) => {
                 const idProduto = item.idProduto || item.ID_Produto || '';
                 if (!idProduto) continue;
 
+                const delta = parseInt(item.delta_estoque) || 0;
+                const nomeStr = item.nome || item.Descricao_Produto || 'Unknown';
+
                 const values = [
                     String(idProduto),
-                    item.nome || item.Descricao_Produto || 'Unknown',
+                    nomeStr,
                     parseInt(item.saldo) || 0,
-                    parseInt(item.delta_estoque) || 0
+                    delta
                 ];
                 await client.query(insertQuery, values);
+
+                // Waiting Room / Debounce Logic
+                if (delta >= 100) {
+                    const baseProductName = nomeStr.split(' TAMANHO')[0].trim();
+                    
+                    if (!waitingRoom[baseProductName]) {
+                        console.log(`[Waiting Room] Nova entrada: ${baseProductName}. Iniciando timer de 30m...`);
+                        waitingRoom[baseProductName] = {
+                            total_delta: 0,
+                            items: [],
+                            timeout: null
+                        };
+                    } else {
+                        console.log(`[Waiting Room] Atualização: ${baseProductName}. Timer reiniciado (30m).`);
+                    }
+
+                    waitingRoom[baseProductName].total_delta += delta;
+                    waitingRoom[baseProductName].items.push({
+                        id: String(idProduto),
+                        nome: nomeStr,
+                        delta: delta,
+                        saldo: parseInt(item.saldo) || 0
+                    });
+
+                    if (waitingRoom[baseProductName].timeout) {
+                        clearTimeout(waitingRoom[baseProductName].timeout);
+                    }
+
+                    waitingRoom[baseProductName].timeout = setTimeout(async () => {
+                        try {
+                            const aggData = waitingRoom[baseProductName];
+                            delete waitingRoom[baseProductName]; // Clear from waiting room
+                            
+                            console.log(`[Waiting Room] Timer finalizado para ${baseProductName}. Buscando top buyers...`);
+
+                            // Find Top 100 buyers for this Base Product
+                            const topBuyersQuery = `
+                                SELECT 
+                                    MAX(cliente_nome) as nome, 
+                                    cliente_fone as fone, 
+                                    SUM(quantidade) as total_comprado 
+                                FROM orders 
+                                WHERE produto_descricao LIKE $1 
+                                  AND cliente_fone IS NOT NULL 
+                                  AND cliente_fone != '' 
+                                GROUP BY cliente_fone 
+                                ORDER BY total_comprado DESC 
+                                LIMIT 100;
+                            `;
+                            const topBuyersResult = await pool.query(topBuyersQuery, [`${baseProductName}%`]);
+                            
+                            // Only trigger if we actually have buyers
+                            if (topBuyersResult.rows.length > 0) {
+                                console.log(`[Waiting Room] Disparando webhook do WhatsApp para ${topBuyersResult.rows.length} clientes (${baseProductName})...`);
+                                fetch(N8N_WHATSAPP_TRIGGER_URL, {
+                                    method: 'POST',
+                                    headers: { 'Content-Type': 'application/json' },
+                                    body: JSON.stringify({
+                                        baseProduct: baseProductName,
+                                        total_delta: aggData.total_delta,
+                                        sizes: aggData.items,
+                                        customers: topBuyersResult.rows
+                                    })
+                                }).then(res => {
+                                    if(res.ok) console.log(`[Waiting Room] Sucesso! Webhook disparado.`);
+                                    else console.log(`[Waiting Room] Aviso: Webhook retornou status ${res.status}`);
+                                }).catch(err => console.error("Failed to trigger WhatsApp webhook:", err));
+                            } else {
+                                console.log(`[Waiting Room] Nenhum cliente encontrado com telefone válido para ${baseProductName}. Webhook cancelado.`);
+                            }
+                        } catch (err) {
+                            console.error("Error in Waiting Room timeout:", err);
+                        }
+                    }, 1800000); // 30 minutes
+                }
             }
             
             await client.query('COMMIT');