Job Description: Software Development Engineer in Test (SDET), OSS/BSS
Job Title: Software Development Engineer in Test (SDET), OSS/BSS
Location: Pune, India
Reports To: Engineering Manager
About Telna
Telna provides Mobile Network Operators (MNOs), Communication Service Providers (CSPs), and Original Equipment Manufacturers (OEMs) with a fully managed global cellular connectivity platform. With access to the largest 2G–5G and LTE-M coverage from over 800 radio network operators—300 of which are direct partners—across 200 countries, Telna empowers seamless, high-performance connectivity worldwide.
Our global multi-network connectivity platform simplifies integration, offering localized break-out capabilities via cloud infrastructure. With a single integration into Telna's platform, millions of devices are powered by resilient, multi-network connectivity—enabling a wide array of innovative cloud-based solutions.
Position Overview
We are seeking an experienced Software Development Engineer in Test (SDET) to join our engineering organisation and operate as a core developer on quality. You will design and build the platforms, frameworks, tooling, and infrastructure that make our OSS/BSS systems (network provisioning, inventory, CRM, billing, charging, and mediation) testable, observable, and releasable with confidence at telecom scale.
Unlike a traditional QA role, you will spend most of your time writing production-quality software—test harnesses, simulators, data generators, CI/CD tooling, service virtualisation, and contributions into product code to improve testability. You will partner closely with backend, platform, and DevOps engineers, treat test infrastructure as a first-class product, and raise the engineering bar for quality across distributed, high-volume telecom services.
Key Responsibilities
- Design, build, and own end-to-end test platforms and frameworks for Java-based microservices, event-driven systems, and the GUI applications that sit on top of OSS/BSS components.
- Write production-quality code in Java (and supporting languages such as Python, Kotlin, or TypeScript) for test libraries, harnesses, SDKs, CLIs, and shared abstractions used across the engineering organisation.
- Build simulators, stubs, mocks, and service virtualisation for upstream/downstream telecom systems (network elements, mediation feeds, charging gateways, payment systems) to enable deterministic, isolated testing.
- Contribute directly to product code to improve testability—adding hooks, feature flags, contract definitions, observability, and clean seams between modules—as a peer of the backend developers.
- Design and implement end-to-end automated coverage spanning APIs, backend services, databases, message queues, and GUI workflows for CRM, billing, mediation, provisioning, and charging.
- Architect CI/CD test infrastructure (Jenkins, GitLab CI, GitHub Actions, ArgoCD): pipeline design, parallelisation, ephemeral environments, test data provisioning, quality gates, flaky-test detection, and self-service tooling for other engineers.
- Build automation that validates Call Detail Records (CDR/EDR), rating, charging, and invoicing flows end-to-end, ensuring revenue assurance and data integrity at scale.
- Design and run performance, load, soak, and resilience tests (JMeter, Gatling, k6, chaos tooling) for high-throughput telecom workloads, and turn the results into actionable engineering improvements.
- Drive a strong shift-left culture: pair with developers on testability, review their unit/integration tests in code review, and own framework-level patterns that the wider team builds on top of.
- Investigate complex failures across distributed services using logs, traces, metrics, and packet captures; isolate root causes, file high-quality defects, and contribute fixes where appropriate.
- Mentor QA and SDET engineers on software engineering practices, design patterns, framework design, and code quality; act as a technical reference for test engineering across the team.
- Participate in architecture discussions, design reviews, and Agile ceremonies; advocate for quality and testability as architectural concerns, not after-thoughts.
Required Qualifications
- 5+ years of software engineering experience, with significant time spent building test platforms, frameworks, or developer tooling (not just authoring test cases).
- Strong hands-on programming skills in Java (OOP, collections, concurrency, exception handling, design patterns) at a level comparable to a backend software engineer; ability to design, review, and ship production-quality code.
- Proven experience designing automation frameworks and test platforms from scratch, including architecture, modularity, extensibility, and adoption across multiple teams.
- Hands-on experience automating REST/HTTP APIs and backend services using REST Assured, Karate, or similar frameworks, including contract-style testing.
- Hands-on experience automating GUI applications using Selenium WebDriver, Playwright, or equivalent—including Page Object Model, dynamic UIs, waits, and cross-browser execution.
- Solid experience with build tools (Maven or Gradle), version control (Git), and modern code review workflows.
- Experience designing and operating CI/CD pipelines (Jenkins, GitLab CI, GitHub Actions, etc.) including parallel execution, test reporting, quality gates, and flaky-test mitigation.
- Proficiency in SQL for database verification and data setup; comfort with scripting languages (Python, Bash) for tooling and automation.
- Solid understanding of distributed systems, microservices, asynchronous messaging, and cloud-hosted architectures, and how each of these affects testing strategy.
- Strong understanding of REST APIs, HTTP, JSON, and common authentication mechanisms (tokens, OAuth, mTLS).
- Experience with test management and issue tracking tools (Jira, Confluence, TestMo, ALM, or similar) and treating quality data as a product.
- Strong analytical, troubleshooting, and problem-solving skills, including the ability to read logs, traces, and data records (CDRs, CSVs, DB tables) to isolate root causes.
- Strong written and spoken English communication skills, and the ability to work independently as well as in a global cross-functional team.
Preferred Qualifications
- Experience working in telecom OSS/BSS environments (CRM, billing, mediation, provisioning, charging) or MVNO/MVNE platforms.
- Familiarity with telecom protocols (e.g., SNMP, Diameter, SS7 concepts) and OSS/BSS architecture.
- Experience validating eSIM, SIM lifecycle, or mobile connectivity workflows.
- Experience with Charging, Rating, and Mediation systems, and with Online Charging Systems (OCS).
- Hands-on experience with public cloud platforms (AWS, GCP, or Azure) and containerised environments (Docker, Kubernetes, Helm).
- Experience with infrastructure-as-code (Terraform, Pulumi) and building ephemeral or on-demand test environments.
- Experience with message queues and event-driven systems (Kafka, RabbitMQ), including testing event-driven contracts.
- Experience with performance testing tools (JMeter, Gatling, k6), chaos engineering, and network tracing (Wireshark).
- Experience with contract testing (Pact), BDD frameworks (Cucumber, Karate), and consumer-driven testing strategies.
- Exposure to security testing (SAST/DAST, OWASP) and to supporting UAT and customer pilots.
- Open-source contributions to test frameworks, developer tooling, or quality infrastructure.
Why Join Us
- Contribute to the advancement of cutting-edge telecom technologies and infrastructure.
- Collaborate with a diverse, experienced, and multicultural team of engineers and industry professionals.
- Enjoy a flexible work environment with remote work options.
- Receive a competitive salary and a comprehensive benefits package.
- Grow your career through professional development opportunities and technical training.
