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Case study · Telecommunications

Cloud-Native API Platform

Scaling enterprise APIs for high-volume digital services

Industry
Telecommunications
Focus
API Modernization · Cloud Native · Kubernetes · Microservices · Platform Engineering
Engagement
Architecture & Engineering
Overview

Scaling enterprise APIs for high-volume digital services

Modern telecommunications services depend heavily on APIs. Customer mobile applications, websites, retail channels, contact centers, partner ecosystems and internal platforms all rely on APIs to access customer, product, ordering, billing, payment, provisioning and operational capabilities.

As digital adoption grows, these APIs must support increasingly large transaction volumes while maintaining availability, predictable performance, security and operational visibility.

Traditional application and integration architectures can become difficult to scale when workloads increase rapidly or when hundreds of APIs share common infrastructure.

Digital Sarthi contributed architecture and engineering capabilities to modernize enterprise API workloads using a cloud-native API platform combining API management, containerized microservices, Kubernetes, automated CI/CD, observability and performance engineering.

The objective was to establish a platform capable of supporting high-volume API traffic and evolving digital services without requiring every application team to independently solve scalability, security and operational concerns.

Results at a glance
3–5x Higher throughput

Able to handle significantly more API transactions after modernization.

99.95% Improved availability

A more resilient platform, up from 99.5%, with reduced downtime.

~70% Lower latency

Faster API response times: from 450 ms to 120 ms.

~10x Less downtime

Self-healing architecture reduces the impact of failures.

3–5x Faster releases

Deployment of new features and updates moved from weeks to days.

80–90% Resource utilization

Average infrastructure utilization through auto scaling, up from 60%.

Developer building software at a workstation
The challenge

Growing digital services created increasing API demand

Telecommunications APIs support a broad range of customer and operational journeys:

  1. Digital Channels
  2. APIs
  3. Enterprise Services
  4. Systems of Record

Typical transactions include:

As more customer interactions shifted toward digital channels, API traffic increased substantially. The architecture therefore needed to evolve from supporting individual integrations to operating APIs as a high-volume enterprise platform.

Increasing Transaction Volumes

Digital traffic is rarely constant. API workloads can experience significant changes based on:

  • Customer campaigns
  • Product launches
  • Billing cycles
  • Service events
  • Mobile application releases
  • Seasonal activity
  • Partner traffic
  • Operational incidents

Infrastructure sized around average traffic can struggle during peaks. The platform needed the ability to dynamically scale processing capacity according to demand.

Availability Became Business Critical

When APIs become the integration layer for digital channels, an API failure can affect multiple customer journeys simultaneously.

  1. API Platform Unavailable
  2. Mobile App Impacted
  3. Website Impacted
  4. Contact Center Impacted
  5. Partner Integrations Impacted
  6. Internal Applications Impacted

High availability therefore needed to be designed across the complete architecture rather than only at the application level.

Application Scaling Was Not Enough

Adding more application instances does not automatically create a scalable platform. Potential bottlenecks can exist across:

  1. API Gateway
  2. Load Balancer
  3. Application
  4. Database
  5. Cache
  6. Downstream APIs
  7. Network

Scaling therefore required understanding the complete request path. For example, doubling application instances provides little benefit if all requests eventually reach a downstream system with limited capacity.

Complex Enterprise Integrations

Telecommunications APIs often aggregate information from multiple systems. A single customer request might require:

  1. API Request
  2. Customer Service
  3. Billing + Product + Order + Service Platforms
  4. Aggregate Response

Latency or failure in any downstream dependency can affect the overall API response. The architecture therefore required resilience patterns capable of isolating downstream problems.

Security Across a Large API Estate

As API adoption increased, security needed to be implemented consistently. Controls included areas such as:

  • Authentication
  • Authorization
  • TLS
  • API keys and tokens
  • Rate limiting
  • Secrets management
  • Input validation
  • Network policies
  • Access logging
  • Audit
  • Threat protection

Implementing these controls independently within every API would create inconsistency and duplicated effort.

Operational Visibility

High-volume APIs generate large quantities of operational data. Teams needed to understand:

  • How much traffic is the platform processing?
  • Which APIs have the highest latency?
  • Which services are producing errors?
  • Is the problem inside the API or downstream?
  • Are containers running out of CPU or memory?
  • Are requests being throttled?
  • Which customer journeys are affected?

Traditional application logs alone were not sufficient.

Our approach

A repeatable modernization lifecycle

Digital Sarthi structured the API modernization approach around a repeatable lifecycle:

  1. Assess
  2. Standardize
  3. Containerize
  4. Platform
  5. Secure
  6. Automate
  7. Observe
  8. Optimize

The objective was to modernize both the application architecture and the engineering practices required to operate APIs at scale.

  1. Assess the Existing API Landscape

    The first step was understanding the existing API ecosystem. The assessment considered:

    • API inventory
    • Traffic volumes
    • Peak transaction rates
    • Existing infrastructure
    • Application dependencies
    • Downstream integrations
    • Performance characteristics
    • Security requirements
    • Deployment processes
    • Operational incidents
    • Availability requirements

    APIs could then be classified according to characteristics such as:

    • Business Criticality
    • Traffic
    • Latency
    • Availability
    • Complexity
    • Dependency Risk

    This provided the foundation for modernization priorities.

  2. Establish API Standards

    A scalable platform requires consistency. Common API engineering standards were established around areas such as:

    API Design

    REST conventions · Resource modeling · HTTP methods · Status codes

    Contracts

    OpenAPI specifications · Schema standards · Versioning

    Security

    Authentication · Authorization · Encryption · Access policies

    Error Handling

    Standard error structures · Correlation IDs · Error classifications

    Reliability

    Timeouts · Retry policies · Idempotency

    Observability

    Logging · Metrics · Tracing · Health checks

    This reduced differences between individual services and simplified platform operations.

  3. Containerize API Workloads

    API applications were packaged as containers, creating a consistent runtime model across environments.

    1. Source Code
    2. Build
    3. Container Image
    4. Container Registry
    5. Kubernetes Deployment

    Containerization enabled:

    • Runtime consistency
    • Immutable deployments
    • Independent service releases
    • Horizontal scaling
    • Resource isolation
    • Automated deployment
    • Faster recovery

    Applications could then evolve independently rather than being tied to shared application-server infrastructure.

  4. Deploy on Kubernetes

    Kubernetes provided the orchestration foundation for containerized API workloads. The platform could manage:

    Deployment

    Declarative deployment of application workloads.

    Scaling

    Increase or decrease application replicas according to demand.

    Service Discovery

    Allow services to discover and communicate with each other.

    Health Management

    Detect unhealthy containers and replace them automatically.

    Resource Management

    Control CPU and memory allocation.

    Rolling Deployment

    Introduce new application versions gradually.

    Resilience

    Redistribute workloads when infrastructure components fail.

    This shifted significant infrastructure management from manual operational activities toward automated platform capabilities.

  5. Introduce an API Management Layer

    API management provided a controlled entry point into enterprise services.

    1. Digital Channel / Partner / Enterprise Application
    2. API Gateway / API Management
    3. Kubernetes Services
    4. Enterprise Systems

    The API management layer could provide:

    • Authentication
    • Authorization
    • Rate limiting
    • Traffic management
    • Routing
    • API versioning
    • Policy enforcement
    • Request transformation
    • Analytics
    • Developer access

    This separated cross-cutting API concerns from individual business services.

  6. Design for Microservices

    Where appropriate, large API applications could be decomposed into independently deployable services aligned with business capabilities. Examples might include:

    • Customer Service
    • Account Service
    • Product Service
    • Qualification Service
    • Order Service
    • Payment Service
    • Notification Service

    Each service can be:

    1. Developed
    2. Tested
    3. Deployed
    4. Scaled
    5. Monitored

    independently. The objective was not simply to create more services, but to establish appropriate boundaries that improved scalability and deployment independence.

  7. Build Resilience into API Processing

    Cloud-native APIs need to assume that dependencies can become slow or unavailable. Resilience patterns included:

    Timeout Management

    Prevent requests from waiting indefinitely for downstream services.

    Controlled Retry

    Retry transient failures where the operation is safe to repeat.

    Circuit Breakers

    Temporarily stop requests to an unhealthy dependency.

    Bulkheads

    Prevent problems in one dependency from consuming all available resources.

    Rate Limiting

    Protect services from excessive request volumes.

    Back-Pressure

    Control workload when downstream processing cannot keep pace.

    Graceful Degradation

    Return partial or alternative functionality where business requirements permit.

    Together, these patterns reduce the probability that a single failing component causes a wider platform outage.

  8. Automate Build & Deployment

    A cloud-native platform also requires modern software delivery practices. A typical delivery pipeline became:

    1. Developer Commit
    2. Build
    3. Unit Test
    4. Security Scan
    5. Container Build
    6. Image Scan
    7. Publish Artifact
    8. Deploy
    9. Automated Validation
    10. Promote

    Deployment strategies could include:

    • Rolling Deployment
    • Blue/Green
    • Canary

    depending on service criticality and operational requirements. This reduced manual deployment activities and improved release repeatability.

Solution architecture

Seven logical layers

The Cloud-Native API Platform can be represented through seven logical layers.

  1. Consumer & Channel Layer

    • Mobile
    • Web
    • Contact Center
    • Retail
    • Partners
    • Enterprise Applications
  2. Edge & API Management

    • API Gateway
    • Authentication
    • Authorization
    • Routing
    • Rate Limiting
    • Security Policies
  3. Cloud-Native Application Platform

    • Kubernetes
    • Containers
    • Services
    • Ingress
    • Service Discovery
    • Auto Scaling
  4. Microservices & APIs

    • Customer
    • Product
    • Order
    • Billing
    • Payment
    • Provisioning
    • Notification
  5. Integration Layer

    • REST APIs
    • Events
    • Queues
    • Enterprise Connectors
    • Integration Services
  6. Enterprise Systems

    • CRM
    • Billing
    • Ordering
    • Product
    • Network
    • Provisioning
    • Payments
  7. Data & Platform Services

    • Databases
    • Cache
    • Eventing
    • Secrets
    • Configuration
    • Logging
    • Monitoring

Across every layer:

API Request Lifecycle

A typical API request can follow:

  1. Customer / Application
  2. Load Balancer
  3. API Gateway
  4. Authentication & Policy Validation
  5. Kubernetes Ingress
  6. Microservice
  7. Cache / Database / Downstream API
  8. Response

At each stage, telemetry can be captured. For example:

  1. Correlation ID
  2. Gateway Trace
  3. Service Trace
  4. Downstream Trace
  5. Response

This creates end-to-end visibility into the transaction.

Scaling & performance

Scaling high-volume APIs

Scalability was designed across multiple layers rather than only at the application level.

Horizontal Application Scaling

Multiple service instances distribute incoming traffic:

  1. Service
  2. Pod 1
  3. Pod 2
  4. Pod 3
  5. Pod N

Additional replicas can be introduced as demand increases.

Auto Scaling

Scaling can respond to indicators such as:

  • CPU
  • Memory
  • Request rate
  • Queue depth
  • Custom application metrics

Independent Service Scaling

High-demand services can scale independently. For example:

  • Customer API — 20 replicas
  • Product API — 8 replicas
  • Order API — 12 replicas

This prevents the platform from scaling every component equally when only one capability is under pressure.

Performance Engineering

High-volume API platforms require performance engineering throughout the lifecycle.

Load Testing

Validate expected production traffic.

Stress Testing

Determine behavior beyond expected capacity.

Endurance Testing

Identify resource leaks or degradation over extended periods.

Spike Testing

Validate sudden traffic increases.

Dependency Testing

Understand how downstream latency affects the API.

Performance optimization can focus on:

The objective is not simply achieving a single response-time target—it is maintaining predictable performance as traffic increases.

Observability

Observability as a platform capability

Observability was treated as a platform capability rather than an afterthought.

Metrics

  • Request Rate
  • Response Time
  • Error Rate
  • CPU
  • Memory
  • Pod Count
  • Queue Depth

Logs

Centralized structured logging enables investigation across distributed services.

Distributed Tracing

A transaction can be followed across Gateway → API → Service → Database → Downstream Service.

Health Checks

Applications expose health information used by the platform for traffic routing and recovery.

Dashboards

Operational dashboards provide visibility into Traffic · Latency · Availability · Errors · Resource Utilization · Dependency Health.

Alerts

Teams can be notified when thresholds or service objectives are breached.

Key capabilities

What the platform brings together

API Engineering

Design and build standardized, secure and reusable enterprise APIs.

Cloud Native

Use cloud infrastructure patterns designed around elasticity, automation and resilience.

Kubernetes

Operate containerized workloads using automated deployment, scaling, health management and recovery.

Microservices

Create independently deployable and scalable services aligned with appropriate business capabilities.

API Management

Centralize security, traffic management, policies, routing and API analytics.

DevOps

Automate application build, testing, security validation and deployment.

Observability

Provide centralized metrics, logs, tracing, dashboards and alerts.

Performance Engineering

Validate platform capacity and optimize APIs for high-volume workloads.

Security

Implement consistent identity, access, secrets, network and API protection controls.

Resilience

Apply timeouts, retries, circuit breakers, isolation and recovery patterns.

Auto Scaling

Dynamically adjust application capacity according to workload.

Platform Engineering

Provide reusable infrastructure and deployment capabilities that application teams can consume consistently.

Before & after

From traditional APIs to a cloud-native platform

Before

  1. Channels
  2. Load Balancer
  3. Shared API/Application Layer
  4. Enterprise Systems

Common challenges can include:

  • Manual Scaling
  • Shared Failure Domains
  • Slow Deployment
  • Limited Observability
  • Infrastructure Dependencies

After

  1. Digital Channels & Enterprise Consumers
  2. API Management
  3. Cloud-Native Platform
  4. Containerized Microservices
  5. Enterprise Systems & Data

Supported by:

  • Auto Scaling
  • CI/CD
  • Observability
  • Security
  • Resilience

This creates a platform capable of evolving as API traffic and digital services grow.

Operational control

Visibility at every level

A cloud-native platform gives engineering and operations teams visibility at several levels.

API Level

Request volume · Latency · Success rate · Errors

Application Level

Service health · Dependencies · Application metrics

Kubernetes Level

Pods · CPU · Memory · Restarts · Scaling

Infrastructure Level

Compute · Network · Storage · Availability

Business Transaction Level

Customer journey · Correlation ID · Transaction status

Combining these perspectives allows teams to move quickly from:

"The API is slow"

"This downstream dependency is contributing most of the transaction latency."

That difference significantly improves operational diagnosis.

Engineering for High Availability

High availability requires eliminating single points of failure across the complete request path. The platform can incorporate:

  1. Multiple Application Instances
  2. Kubernetes Node Distribution
  3. Load Balancing
  4. Multi-Zone Deployment
  5. Replicated Data Services
  6. Automated Health Checks
  7. Self-Healing Containers
  8. Controlled Failover
  9. Disaster Recovery

Combined with observability and automated recovery, these patterns improve the ability of the platform to continue operating when individual components fail.

Results

A more scalable and resilient foundation

The Cloud-Native API Platform established a more scalable and resilient foundation for enterprise integrations and digital services.

It enabled organizations to:

  1. Support growing API transaction volumes
  2. Scale services independently according to demand
  3. Improve platform availability
  4. Reduce dependency on manual infrastructure scaling
  5. Standardize API security
  6. Improve deployment consistency
  7. Accelerate application releases
  8. Improve visibility into distributed transactions
  9. Detect performance issues earlier
  10. Reduce recovery time through automated health management
  11. Isolate failures more effectively
  12. Improve infrastructure utilization
  13. Support new digital channels
  14. Simplify enterprise API consumption
  15. Establish reusable engineering patterns

Most importantly, the architecture shifted APIs from being individual application interfaces to a strategic enterprise platform capability.

Enabling Faster Digital Innovation

A reusable API platform reduces the amount of infrastructure and integration work required when introducing new digital experiences.

Instead of every application building:

the platform provides these capabilities centrally.

Application teams can focus more heavily on:

This creates a model where Platform Engineering provides reusable capabilities to API & Product Teams, which accelerate delivery to Digital Channels & Enterprise Consumers.

  1. Platform Engineering
  2. API & Product Teams
  3. Digital Channels & Enterprise Consumers

Foundation for API & AI-Driven Services

The same architecture can also support emerging AI and agent-driven enterprise workloads.

AI applications frequently need controlled access to enterprise capabilities such as:

A governed API platform can provide that access while maintaining:

This allows future AI services and agents to consume enterprise capabilities through the same controlled integration foundation used by traditional applications.

Technology & engineering

Capabilities we applied

API Platform

  • API Gateway
  • API Management
  • REST
  • OpenAPI

Cloud Native

  • Containers
  • Kubernetes
  • Service Discovery
  • Auto Scaling

Microservices

  • Domain Services
  • Stateless Processing
  • Independent Deployment

Integration

  • REST
  • Events
  • Queues
  • Enterprise Connectors

DevOps

  • CI/CD
  • Infrastructure Automation
  • Automated Testing
  • Release Automation

Security

  • OAuth/OIDC
  • TLS
  • RBAC
  • Secrets
  • Network Policies
  • API Policies

Resilience

  • Timeouts
  • Retry
  • Circuit Breakers
  • Bulkheads
  • Graceful Degradation

Performance

  • Load Testing
  • Stress Testing
  • Capacity Planning
  • Optimization

Observability

  • Metrics
  • Logs
  • Distributed Tracing
  • Dashboards
  • Alerts

Operations

  • Health Monitoring
  • Auto Recovery
  • SLA/SLO Monitoring
  • Incident Diagnostics
A reusable foundation

Building a reusable enterprise API foundation

The long-term value of cloud-native modernization extends beyond migrating individual APIs. It establishes a reusable platform:

  1. Digital Channels & Enterprise Consumers
  2. API Management & Security
  3. Cloud-Native API Platform
  4. Microservices & Enterprise APIs
  5. Enterprise Systems & Data

supported by:

As traffic increases or new services are introduced, the organization can scale the platform rather than repeatedly redesigning the integration architecture.

The result is an API ecosystem designed to be scalable, resilient, observable, secure and continuously deployable.

Related solutions

Solutions behind this work

More case studies

Scale digital services with a modern API foundation

Digital Sarthi helps organizations modernize high-volume enterprise APIs through cloud-native architecture, Kubernetes, microservices, API management, DevOps, performance engineering, resilience and observability.

The objective is to build an API platform capable of supporting today's enterprise integrations while providing the scalability and engineering foundation required for tomorrow's digital and AI-driven services.