Set up an AWS Client VPN endpoint associated with a VPC subnet, configure a Client VPN self-service portal, and guide developers to connect using the Client VPN client.

Establish a transit gateway connected to the VPC, create an AWS Site-to-Site VPN with an attachment to the transit gateway, and instruct developers to use an OpenVPN client for connection.

Deploy a transit gateway linked to the VPC, arrange an AWS Direct Connect connection with a public VIF set up on the Direct Connect connection, associate the public VIF with the transit gateway, and advise developers to connect via the Direct Connect connection.

Deploy a bastion host in a public subnet of the VPC, set up the bastion host security group to permit SSH access from the company's CIDR ranges, and direct developers to connect using SSH.