Avoid hardcoding deployment-specific values—such as usernames, channel IDs, thresholds, or other identifiers—directly in source code. Instead, define them as environment variables or config entries (e.g., `CLICKHOUSE_HQL_USER` instead of a literal `"hql_user"`, or `ALERT_BANNER_ID_DELAY_IN_QUEUE`/`FIRE_ALERT_CHANNEL` as env vars rather than inline constants). This is especially important for self-hosted or multi-environment deployments where these values must be customizable without code changes. Additionally, when a feature depends on optional configuration (e.g., Slack webhook/channel settings), guard the code path so it skips gracefully if that configuration is not set, rather than attempting the action and failing. For example: ```ts if (!env.SLACK_ALERT_CHANNEL) { return; // skip sending alert if not configured } await alertManager.sendSlackMessageToChannel(env.SLACK_ALERT_CHANNEL, ...); ``` This keeps configuration centralized, makes deployments portable, and prevents runtime failures when optional settings are absent.