US Telco Mainframe Modernization with Cloud-Native Microservices

Client

A leading US telecommunications provider embarked on a large-scale transformation to modernize its consumer wireless applications operating on legacy mainframe systems

Challenges

High recurring costs from legacy mainframe and IBM Db2 platforms
Slow time‑to‑market due to rigid schemas and long development cycles
Complex COBOL dependencies limiting modernization speed
Fragmented data across multiple systems

Solution

Performed a detailed assessment of 8,000+ mainframe batch jobs
Re‑engineered the legacy workloads into a cloud‑native microservices model deployed on AWS
Retired 900 legacy jobs and modernized 290+ jobs using technologies such as Spring Boot, Angular, Spring Batch, Kafka-optimized for AWS runtime environments
Introduced cloud‑native, parallelized, and chunk‑based batch processing frameworks that leveraged AWS scalability
Embedded DevSecOps, CI/CD, and SRE practices aligned to AWS deployment standards
Executed a phased migration with controlled cutover, end‑to‑end validation, and enhanced observability

Outcomes Delivered

$7.35M annual TCO savings
900 legacy batch jobs retired
290+ jobs modernized and migrated
4,900 MIPS monthly reduction in mainframe consumption

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Contributors

Dhiraj Thakur is a Solutions Architect with Amazon Web Services, specializing in Generative AI and data analytics domains. He works with AWS customers and partners to architect and implement scalable analytics platforms and AI-driven solutions. With deep expertise in Generative AI services and implementation, end-to-end machine learning implementation, and cloud-native data architectures, he helps organizations harness the power of GenAI and analytics to drive business transformation. He can be reached via LinkedIn

Harish Bansal is a Senior Principal Technology Architect at Infosys with 20+ years of experience in telecom platforms spanning BSS/OSS, Digital, and AI. He leads Cloud and Digital Architecture for the CMT segment and the services.ai track, specializing in high‑throughput, low‑latency, and cost‑optimized platforms at enterprise scale

Vikas Kapoor is a Senior Technology Architect at Infosys with over 20 years of experience in enterprise architecture, technology consulting, and cloud solutions. His expertise spans the design and development of microservices, cloud-based architectures, application migration, and modernization, as well as large scale digital transformation initiatives