Case Study
UST helps a top telco provider strengthen API resilience to support 3.3B daily transactions and 99% reliability
OUR CLIENT
Our client is a global telecommunications provider operating one of the world’s largest consumer and enterprise mobility networks. This multinational telecommunication company was founded decades ago after a series of mergers and acquisitions. The company owns cellular service providers across North America and Europe that serve more than 100 million customers with a range of voice, messaging, data, and high-speed connectivity products. Its business depends on a high-throughput, Application Programming Interface (API)-driven ecosystem to deliver reliable, secure, and always-on services across multiple channels and markets.
THE CHALLENGE
API scale outpaced control, consistency, and confidence
As digital demand accelerated, the company’s API landscape expanded rapidly across teams, channels, and partners. While API use grew, the underlying operating model did not keep pace.
Key business challenges emerged:
- Rising continuity risk: Fragmented gateway patterns made it harder to ensure consistent performance during peak demand.
- Security exposure: Inconsistent API security and governance increased risk across external integrations.
- Operational drag: Manual onboarding and fragmented API lifecycle management slowed delivery and increased overhead.
- Limited visibility: Teams lacked a unified view of API usage, ownership, and reuse across the enterprise.
APIs had become mission-critical infrastructure. Any failure, latency spike, or security incident directly impacted revenue, customer trust, and brand reputation. Leadership needed a more disciplined approach to telecom digital transformation before scale became a liability.
THE TRANSFORMATION
Establishing an enterprise API Center of Excellence
UST partnered with the organization to establish a scalable API Centre of Excellence (CoE), anchored in a future-ready enterprise API management model. The program aligned technology delivery to business outcomes while enabling secure growth across the Content Security Policy (CSP) API platform.
The team delivered a modern API gateway platform architecture to manage high-scale traffic while centrally enforcing enterprise policies. Security was strengthened through standardized API authentication and authorization, including certificate-based authentication APIs, Zero Trust API architecture, and advanced encryption, including Post-Quantum TLS (PQTLS).
Operational resilience improved through API SRE (Site Reliability Engineering), performance tuning, API observability and monitoring, and optimized API traffic management across channels. UST also supported the development of the API control plane to manage policies, routing, and lifecycle workflows.
Developer experience advanced through API developer experience (DX) improvements, including API onboarding automation, credential self-service, and guided enablement. Meanwhile, intelligence matured through AI-enabled developer platforms, AI-powered API discovery, Language Learning Models (LLM)-based API search, and Intelligent API governance. Teams gained insights through agent-assisted API management, NLP-driven API enablement, and an enterprise API knowledge graph, improving reuse and delivery speed.
These upgrades formed the foundation of the customer’s enterprise API platform, delivering a resilient and secure telecom developer environment aligned to long-term growth and scalable innovation.
THE IMPACT
Delivering billion-scale performance and carrier-grade reliability
The API transformation delivered a step-change in performance, resilience, and business agility—directly strengthening revenue protection, customer experience, and operational continuity. By modernizing the architecture into a high-throughput, low-latency API platform, the enterprise can now reliably handle billion-scale traffic while maintaining carrier-grade stability.
The new platform processes ~3.3 billion daily transactions across digital, retail, and care channels, ensuring every customer interaction—whether browsing, buying, or seeking support—runs seamlessly. With a ~99% success rate and 99.999% uptime, the system consistently delivers the reliability expected in a mission-critical telecom environment, reducing service disruptions and protecting revenue streams.
Performance gains were equally transformative. Optimized routing now enables ~50ms latency, directly improving user experience and supporting faster delivery of new digital capabilities. Security posture improved dramatically as well, with the platform blocking 15 million intrusion attempts, safeguarding external integrations, and reducing cybersecurity risk.
During high-visibility product launches, the system can scale to 70K transactions per second, significantly increasing previous peak capacity and ensuring flawless execution during major revenue events such as large-scale device launches and seasonal demand spikes.
In addition to performance gains, the transformation delivered substantial cost efficiencies. The migration to the customer’s API gateway platform resulted in over $33 million in annual savings by eliminating legacy licensing and operational costs. Furthermore, token modernization initiatives contributed an additional $13 million in savings, strengthening the overall financial impact.
Together, these gains create a unified, compliant, and scalable telecom API platform that reduces operational risk, accelerates innovation, and unlocks new opportunities for API-driven monetization and competitive growth.
Modernize your APIs with confidence. Discover how UST helps you build secure, resilient, and high-performance telecom API platforms that scale faster and innovate smarter.
RESOURCES
https://www.ust.com/en/insights/the-world-is-opening-with-apis-application-programming-interfaces
https://www.ust.com/en/insights/smart-api-testing-automated-and-with-business-vision