Strong PHP knowledge (the primary backend language used in the project)
Solid experience with MySQL, including schema design, query optimization, and stored procedures
Backend development experience, including building integrations with external APIs
Good understanding of REST APIs, webhooks, message queues, and asynchronous data processing
Experience working with high-load or highly available systems
Experience with logging, monitoring, and troubleshooting distributed systems
Ability to independently work with third-party technical documentation and deliver stable production-ready integrations
Experience communicating with technical support teams and engineering teams of external partners
Experience in the telecom, VoIP, or CPaaS industry
Knowledge of SIP, RTP, WebRTC, and call routing principles
Experience integrating virtual number platforms, SMS providers, and voice service providers
Understanding of telecom billing principles and CDR (Call Detail Record) processing
Hands-on experience with Twilio, Vonage, Telnyx, Plivo, DIDWW, or similar platforms
Knowledge of international phone number regulations, KYC requirements, and local telecom compliance constraints