Twilio/TypeScript expert needed for migration and integration of multiple messaging services

We would like to migrate our messaging and telephony services to Twilio with two goals in mind: -Provide enterprise scale to our telephony services including messaging -Provide a simple to use Flex platform for our call-center / fulfilment team. Consolidating a number of scattered services into a single platform. Requirements: Write a lambda service that can interface with Twilio, one service for each functional area in Twilio (Number Validation, SMS, Voice): -Lookup (Number validation) -Centralized service to allow any service inside our organization to validate if a phone number is a cell phone or not. -Needs an event listener and REST API endpoint. (event schema to be provided) -No need to save the raw response, but the response should be returned in an appropriate manner (either event or REST response) -Outbound Messaging (SMS) -Create a Generalized outbound SMS service. -Allows any service inside our organization to trigger an outbound SMS -Needs an event listener and REST API endpoint. (event schema to be provided) -Record the response as JSON in an S3 bucket -Ensure SMS message response comes back into the SMS channel inside Twilio Flex. -Automatically process STOP requests. -Telephony (Voice) - Place a callback request into a Flex queue for an agent to pick up. -Returns estimated wait times -Log resulting wait time as JSON in an S3 bucket Migrate from current chat service to Twilio chat through Flex. Deliver detailed documentation for each Lambda service. All services should have usage alerts setup. Configure Flex for call, SMS and chat in a single interface Additional Information: - Schemas and data models to be provided. - Contractor will be provided with access to a Github repository to check in all code. Issues will be tracked in this same repository via Github issues or Zenhub. - Contractor will be provided access to Twilio