Senior QA Engineer

Would you like to build a career in a leading multinational IT company? We are looking for a Senior QA Engineer with a strong manual testing background and a technical mindset to join our team. This role is focused mainly on manual and system-level testing, including end-to-end validation, API/backend flows, and investigation of complex issues across the platform. At the same time, we are looking for someone interested in growing toward a more general QA role by contributing to automation efforts, working with existing frameworks, and collaborating on quality improvements across the product. Since 2007, MMDSmart has been a leading supplier in cloud communications, delivering game-changing IT products to businesses in over 100 countries. Our success is fueled by the inspiration and innovative ideas of our team members, encouraging their growth and impacting our Messaging and Voice solutions. These empower our clients to communicate more effectively with their customers. Don’t miss this chance to excel in a rapidly expanding tech company, where your potential and ambitions are not just recognized, but celebrated. Requirements What will you do at MMDSmart? - You will analyze business requirements and technical specifications for both web interfaces and backend, proactively challenging architectural assumptions to prevent issues before they reach production. -You will act as a System Investigator - performing deep-dive analysis of complex multi-channel message flows using platform logs, webhook payloads, and event traces to identify root causes of delivery and logic defects across SMS, Telegram, Viber, and other channels. -You will design and execute advanced end-to-end test strategies that cover the full message lifecycle - from operator action in the web UI, through API and channel gateway, to delivery confirmation - ensuring what the client experiences matches expected behavior. -You will contribute to performance testing efforts using Locust and other tooling, covering throughput of message delivery, API response times under load, and system resilience under concurrent channel activity. -You will drive quality improvements within an Agile environment, participating in architectural reviews and brainstorming sessions to advocate for testability, observability, and system stability. -You will support the existing Playwright-based automation efforts, collaborating with automation engineers to improve coverage for critical UI flows and helping ensure automated quality checks are reliable within the CI/CD pipeline. -You will maintain technical documentation and RCA reports, ensuring that complex, hard-to-reproduce bugs are well-documented and that the team learns from every critical defect. You are a perfect match if you have: -5+ years of software testing experience; -Strong understanding of web platform testing (UI + backend); -Ability to debug logic defects across distributed flows; -REST API testing (Postman, curl, or similar); -Experience validating webhook and callback flows; -Understanding of channel-specific delivery logic; -Understanding API automation (pytest, REST Assured, or similar); -Basic scripting in JS/TS or Python for test tooling; -Experience working in Linux environments and reading server logs; -Familiarity with Docker / Kubernetes for local/staging environments; -Experience with Grafana or similar monitoring/dashboarding tools. Nice to have: -Experience with Playwright or similar E2E framework; -Hands-on experience with Locust, k6, or JMeter; -Testing throughput under concurrent channel load; -Experience integrating tests into CI/CD pipelines; -Understanding of event-driven architecture patterns; -Familiarity with messaging provider APIs; -Understanding of SMS / chat platform delivery mechanics. Benefits Why do talents choose and stay at MMDSmart? Embrace the opportunity to work in a company that cares about: Your Wellness: Access to mental health programs, comprehensive medical insurance, and a sports card*. Your Happiness: Enjoy the company of cool teammates, a friendly atmosphere, a strong mentorship, and a variety of bonuses & corporate gifts. Your Development: Benefit from free educational events & courses, and English classes with native speakers. Your Career: Focus on your professional development in a supportive environment. Work-Life Balance: Choose your working format - remote, office-based, or hybrid and engage in team-building activities. Think this role's got your name on it? Go ahead and apply, we'd love to see what you've got! Equal-Opportunity Employment We are an equal opportunity employer committed to creating a diverse and inclusive work environment. All qualified applicants will receive consideration for employment without regard to race, color, religion, gender, gender identity or expression, sexual orientation, national origin, genetics, disability, age, or veteran status. *Medical Insurance and Sport Card perks are available for employees located in Bulgaria.