SMS Routing Engineer – International A2P Messaging

The SMS Routing Engineer plays a critical role in designing, operating, monitoring, and optimizing international SMS routing across a diverse network of mobile operators, aggregators, SMS hubs, and CPaaS partners worldwide. This position focuses on ensuring maximum message delivery rates, minimizing latency, optimizing routing costs, and maintaining compliance with contractual SLAs. The engineer also safeguards the messaging network against fraud, spam, and grey routes while collaborating closely with Carrier Relations, NOC, Product, Sales, Finance, and Technical Support teams.

Key Responsibilities

- Routing Management: Configure and maintain international SMS routing tables, develop Least Cost Routing (LCR) strategies, implement Quality Based Routing (QBR), design Priority Routing policies, configure failover routing, and implement load balancing across multiple suppliers. Continuously optimize routing based on delivery performance, country-specific policies, routing priorities, and dynamic routing policies.

- Carrier-hosted SMS-FW Management: Engage with SMS-FW managed services, investigate suspected A2P SMS revenue leakages, analyze penetration test results, propose improvements, and act as technical lead on related projects. Liaise with Mobile Operator customers on traffic analysis, revenue performance, and SLA compliance, responding to queries and service requests.

- Carrier-hosted OTT-FW Management: Work with OTT-FW managed services, investigate revenue leakages, analyze penetration tests, propose initiatives, and lead technical projects. Support Mobile Operator customers with traffic and revenue performance, SLA adherence, and service requests related to OTT-FW.

- Monetization Management: Maintain comprehensive reports on traffic levels, analyze traffic data, and propose initiatives to improve traffic and revenue.

- SMS Connectivity: Manage connectivity with SMSCs, SMPP gateways, SMS hubs, carrier interconnects, SS7, SIGTRAN, Diameter (where applicable), REST and HTTP APIs, and WhatsApp Business APIs.

- Routing Supplier Performance Management: Continuously monitor delivery rate, success ratio, latency, throughput, TPS, error codes, DLR accuracy, network availability, message queues, and supplier SLA compliance. Recommend routing changes based on KPI analysis.

- Traffic Optimization: Optimize routing considering cost, quality, delivery speed, customer SLAs, country regulations, network availability, traffic profiles, time-of-day routing, and seasonal traffic.

- Onboarding Support: Assist in onboarding new Mobile Network Operators, SMS Aggregators, SMS Hubs, CPaaS providers, and enterprise messaging partners.

- SMS Fraud Prevention: Monitor and mitigate SMS pumping fraud, artificial traffic inflation, grey routes, SIM farms, SMS spoofing, flash traffic attacks, revenue leakage, routing manipulation, and spam campaigns. Collaborate closely with Fraud Management teams.

- Incident Management: Participate in 24×7 operational support, investigate delivery failures, high latency, low DLR rates, carrier outages, routing loops, network congestion, and customer complaints. Perform root cause analysis and implement preventive measures.

- SMS Reporting: Prepare detailed reports covering delivery KPIs, supplier scorecards, routing efficiency, cost optimization, revenue assurance, traffic trends, SLA compliance, network availability, and customer performance.

Required Qualifications

- Bachelor’s degree in Telecommunications Engineering, Computer Engineering, Computer Science, Electronics Engineering, or Information Technology.

- 3 to 7 years of experience in international A2P messaging with hands-on management of international SMS routing.

- Proven experience working with Tier-1 carriers or global aggregators.

- Strong expertise in SMPP troubleshooting and routing optimization.

- Technical proficiency with SMPP, SS7, SIGTRAN, MAP, SMSC platforms, SMS Firewalls, routing engines, Linux, SQL, Wireshark, and TCP/IP.

- Familiarity with SMPP simulators, SMS analyzers, network monitoring platforms, Grafana, Kibana, Prometheus, Wireshark, Nagios, and Zabbix.

- Competencies including analytical thinking, problem-solving, attention to detail, decision-making under pressure, incident management, customer focus, vendor coordination, time management, communication, and documentation skills.

Preferred Qualifications and Benefits

- Experience with international SMS hubs and managing over 10 million A2P messages per day.

- Exposure to 100+ international carrier connections.

- Knowledge of WhatsApp Business messaging, OTT messaging, and AI-driven routing optimization.

- Familiarity with Diameter, IMS/VoLTE messaging, RCS, WhatsApp Business APIs, and CPaaS architecture.

- Experience with platforms such as OpenMarket, Mitto, GMS, Infobip, Twilio, Sinch, Tata Communications, Route Mobile, LINK Mobility, SAP Digital Interconnect, BICS, and Tata SMS Hub.

This role offers the opportunity to work at the forefront of global messaging infrastructure, ensuring efficient, secure, and cost-effective SMS routing while collaborating with diverse teams and partners worldwide.