Sagar Tomer

Site Reliability Engineer with hands-on experience in observability and production monitoring of Finacle and surrounding banking applications hosted on AWS EKS. Experienced in building and managing observability solutions using Elasticsearch, OpenSearch, Grafana, Prometheus, Logstash, Filebeat, Metricbeat, Wazuh. Skilled in monitoring application availability, performance, logs, metrics, errors, transaction flows, and infrastructure health.

Experienced in incident management, RCA, SLI/SLO monitoring, capacity planning, performance troubleshooting, and proactive alerting to ensure reliability and availability of critical banking applications.

Senior Software Engineer at Quess Corp (2026-08 – Present)

• Provided end-to-end observability for Finacle and surrounding applications hosted on AWS EKS.
• Monitored application logs, metrics, availability, performance, errors, transaction health, and infrastructure resources.
• Used OpenSearch/Elasticsearch for centralized log management, log analysis, troubleshooting, and application performance investigation.
• Developed Grafana dashboards and Prometheus alerts for Finacle, Kubernetes, infrastructure, and supporting services.
• Implemented Filebeat, Metricbeat, and Logstash pipelines for centralized collection and processing of application and infrastructure telemetry.
• Performed incident management, RCA, SLI/SLO monitoring, performance troubleshooting, and capacity planning.
• Correlated logs and metrics across Finacle and dependent applications to identify transaction failures, latency, connectivity, and availability issues.
• Monitored and supported OpenSearch/Elasticsearch clusters, including cluster health, indexing, shards, JVM, storage, and performance.
• Used Wazuh for security monitoring and alerting across the environment.
• Supported observability components running on AWS EKS/Kubernetes and collaborated with application, database, infrastructure, and network teams during production incidents.

Senior Software Engineer at Paytm Payments Bank Limited (2025-06 – 2026-08)

• Designed, implemented, and managed centralized logging solutions using Elasticsearch, Logstash, Kibana (ELK Stack), Filebeat, and Metricbeat for finacle CBS application.
• Configured Logstash pipelines with Grok, Mutate, Date, and Split filters for log parsing, enrichment, and transformation.
• Created and optimized Elasticsearch indices, mappings, templates, ILM policies, snapshots, and cluster configurations.
• Developed Kibana dashboards, visualizations, and alerts to improve operational visibility and troubleshooting efficiency.
• Implemented ElastAlert-based alerting mechanisms for proactive monitoring and incident detection.
• Administered Splunk infrastructure, including forwarders, indexers, search heads, dashboards, and alert configurations.
• Designed and maintained Prometheus monitoring solutions with node/custom exporters.
• Developed Grafana dashboards for infrastructure, application, and business KPI monitoring.
• Conducted root cause analysis (RCA) and performance tuning for Elasticsearch clusters and observability platforms.
• Managed and supported Finacle Core Banking System (CBS) applications in Production, UAT, and DR environments.
• Monitored critical banking services, payment systems, and application health using enterprise monitoring and alerting tools.
• Performed End of Day (EOD), Beginning of Day (BOD), and batch processing activities, ensuring timely completion and issue resolution.
• Provided L2/L3 application support for banking transactions, payment processing, and customer-facing services.
• Monitored application logs, WebLogic servers, JVM performance, and system resources to ensure high availability.
• Investigated and resolved incidents, service disruptions, transaction failures, and performance bottlenecks within SLA timelines.
• Supported payment systems including NEFT, RTGS, IMPS, UPI, and other banking interfaces.
• Managed and monitored Product APIs and Custom APIs, troubleshooting integration and connectivity issues.
• Performed PL-SQL queries and database validation for troubleshooting, data verification, and report generation.
• Coordinated with development, infrastructure, and vendor teams for root cause analysis and permanent fixes.
• Executed source code deployments, application releases, configuration changes, and patch deployments following change management procedures.
• Participated in Disaster Recovery (DR) drills and Data Center (DC) to DR failover/failback activities to validate business continuity.
• Generated operational, transaction, reconciliation, and management reports for stakeholders.
• Configured and managed Jenkins and elastalert alerts for application availability, transaction failures, service degradation, and infrastructure issues.
• Supported middleware components including Oracle WebLogic Server, ensuring application uptime and optimal performance.
• Conducted proactive health checks, capacity monitoring, and preventive maintenance activities.
• Maintained incident records, problem management documentation, SOPs, and knowledge base articles.
• Worked closely with business teams during production issues, major incidents, and critical banking events.
• Ensured compliance with banking operational procedures, audit requirements, and security standards.

Technical Analyst at AU Small Finance Bank (2024-07 – 2025-06)

• Created and managing Elasticsearch cluster for test and production environment.
• Server monitoring using metricbeat.
• Ingesting events from Database using logstash JDBC input plugin.
• Kibana for data visualization and dashboards with Aggregation metrics, Bucket - scripts, Tabular, TVSB.
• Providing support for NEFT RTGS channels in CBS application.
• End to end knowledge of NEFT & RTGS transaction flow.

Senior Software Engineer at Paytm Payments Bank Limited (2018-11 – 2024-05)

• Providing Finacle Support For Production and Testing Environments for Finacle 10.
• Created ELK cluster for nonprod and prod env.
• Provide Support to Finacle Infra Related Queries.
• Maintaining Finacle Services, Logs Managements, Source Deployments.
• Checking CBC logs & FI logs, User Logs.
• Implemented Source Deployment using Bitbucket, git and Jenkins.
• Maintaining Start/Stop/Restart of Finacle Services Using Jenkins.
• Incident Management on Jira.
• Doing Interest Booking and Application.
• Doing Finacle 10 EOD/BOD.
• Created ELK stack for CBS.
• Handling Connect24, FI, UPI, NEFT, RTGS, IMPS, Custom API.
• Extracting reports from database using PLSQL queries and procedure/packages.
• Good hands-on on solaris, linux, plsql.
• Knowledge of source revision tool (svn, git).
• Maintaining DR drill for CBS application.
• Cron setup.
• Able to run query on hue and trino.

Project Engineer at Wipro Limited (2016-01 – 2018-11)

Finacle application engineer with hands on experience of PLSQL programming and Unix Shell Scripting

B.Tech / B.E. – Punjab Technical University (PTU) (2012 – 2016)

XIIth in English (2010 – 2012)

Xth in English (2010)