Senior Backend Engineer – Identity & Security Platform at Vonage

Join Vonage and help us innovate cloud communications for businesses worldwide! Vonage Applications Our Applications business unit focuses on delivering a suite of advanced communication tools designed to enhance customer engagement. From cloud contact centers to feature-rich unified communications solutions, our Applications team is dedicated to providing businesses with the tools they need to streamline operations and improve customer experiences. Why this role matters: Authentication and identity are the front door to every Vonage product — and the Cerberus team is the engineering team that keeps that door secure, reliable, and scalable for hundreds of thousands of business users worldwide. Sitting at the heart of the Vonage Business Communications and Vonage Contact Center platforms, we own the full identity stack — OAuth 2.0 / OIDC, SSO, MFA, SCIM, RBAC/ABAC, fraud detection, and more — processing hundreds of thousands of requests per minute in production. This is not a supporting role; it is core infrastructure where a single decision can affect the security and availability of Vonage's entire product suite. As a Software Engineer joining a team of 6 senior engineers, you will take end-to-end ownership of mission-critical microservices, contribute to the modernization of the VCC identity platform, and help shape the technical direction of a fast-moving, security-first team — with real impact visible at scale from day one. Your key responsibilities: • Design, develop, and maintain authentication and authorization microservices (backend-heavy, full-stack) serving the VBC and VCC platforms • Take full ownership of features end-to-end — from requirement kick-off and solution design through implementation, code review, testing, production deployment, and post-deploy monitoring • Participate actively in Agile ceremonies — daily stand-ups, sprint planning, retrospectives, and design discussions — contributing concrete technical insights and surfacing risks early • Manage production deployments using CI/CD pipelines (GitHub Actions / Bolt), including smoke tests, E2E test execution, log analysis (Kibana / Grafana), and incident response • Implement and maintain security-critical flows including OAuth 2.0, OIDC, SAML 2.0, JWT, MFA, passkey/FIDO, SCIM, and inter-service authentication patterns • Write and maintain technical documentation — architecture decision records, playbooks, runbooks, and knowledge-transfer materials • Participate in on-call rotation (OpsGenie), responding to production alerts, investigating issues, and driving root cause analysis • Leverage AI-assisted development tools (e.g., GitHub Copilot, Claude Code) to enhance personal productivity, code quality, and delivery speed. What you'll bring Required: • 5+ years of professional software engineering experience, with a strong track record of delivering production-quality software in a team environment • Full-Stack developer with a strong server-side orientation — comfortable owning backend services while able to contribute to frontend when needed • Proficiency in Node.js — ability to design, build, and maintain scalable backend services in JavaScript/TypeScript • Hands-on AWS experience — working knowledge of core AWS services (EKS/Kubernetes, EC2, Secrets Manager, WAF, S3, CloudFront, Lambda, ElastiCache) • Microservices architecture — experience designing and operating distributed microservice systems, including service-to-service communication, event-driven patterns (Kafka), and API design • PostgreSQL / relational databases — proficiency in schema design, query optimization, and database best practices • AI-augmented development — active user of AI coding assistants (GitHub Copilot, Claude Code, Cursor, or equivalent) as part of everyday development workflow • Strong software engineering fundamentals — SOLID principles, design patterns, clean code, unit and integration testing. Experience we consider a plus: • Authentication & Authorization deep knowledge — hands-on experience implementing OAuth 2.0, OIDC, SAML, JWT, MFA, SSO, SCIM, or RBAC/ABAC systems • NestJS — experience building backend services with the NestJS framework (the team's emerging standard for VCC services) • DevOps practices — familiarity with CI/CD pipelines, GitHub Actions, infrastructure-as-code (Terraform / CloudFormation / Helm charts), and Kubernetes manifests • C# and/or Java— working knowledge of either language, useful for contributing to legacy components and cross-team integrations. How you’ll benefit: • Discretionary Time Off • Private Medical Healthcare • Pension scheme • Ericsson support line • Hybrid work • Additional benefits and perks will be shared and discussed with you by the recruiter during the interview process. #LI-KF1 There’s no perfect candidate. You don't need all the preferred qualifications to make a valuable impact on our team. Our employees and customers come from diverse backgrounds, so if you're passionate about what you could achieve at Vonage, we'd love to hear from you. To learn how we process your personal data during the recruitment process, please refer to our Privacy Notice. Who we are: Vonage is a global cloud communications leader. And your talent will further help brands - such as Airbnb, Viber, WhatsApp, and Snapchat - accelerate their digital transformation through our fully programmable-based unified communications, contact center solutions, and communications APIs. Ready to innovate? Then join us today. Note: The purpose of this profile is to provide a general summary of essential responsibilities for the position and is not meant as an exhaustive list. Assignments may differ for individuals within the same role based on business conditions, departmental need or geographic location.