Software Engineer 2 - Message Security Products

About the Role Keystone AI AI is redefining cybersecurity with an AI-native platform that protects modern enterprises from advanced email attacks, account compromise, and human-targeted threats. Our products help security teams detect sophisticated attacks, investigate risk quickly, and automate response at enterprise scale. We're building a team of strong engineers who are excited to use modern AI development tools to build faster, make better decisions, and ship high-quality software with more leverage. We're looking for a Software Engineer II, Backend Engineer based in Singapore to join the CEP (Critical Email Products) in the MSP (Message Security Products) organisation. The CEP team ships the capabilities enterprises need to fully consolidate on Keystone AI and remove their legacy email gateway. This is feature parity work with direct business impact, and every capability CEP ships unblocks customers who are ready to move off their SEG but held back by missing functionality. The team currently owns a suite of SEG features that include, but are not limited to, URL Rewriting and Email Digest. If you enjoy moving fast, owning systems end to end, and working alongside engineers who hold a high bar, this is the team and opportunity for you! What You'll Do Build and maintain backend services powering CEP's product surface Design and evolve event-driven pipelines (Kafka consumers, Airflow DAGs) that process email traffic reliably at enterprise scale. Work across a multi-tenant, multi-cloud deployment footprint (M365 and Google Workspace customers, FedRAMP environments) Leverage AI-augmented development tools to explore solutions, refine outputs, and deliver reliable production outcomes faster. Collaborate with product and cross-functional partners to iterate quickly on features that move customers from legacy SEGs to Keystone AI. Contribute to service reliability, observability, and operational quality as the team scales its product surface. Must Haves 3+ years of professional experience in software development. Backend development experience with Python or Golang. Experience building scalable, enterprise-grade applications. Knowledge of cloud platforms (AWS, GCP, or Azure) and containerization (Docker, Kubernetes). Strong fundamentals in computer science, data structures, and performance optimization. Nice to Have Experience with AI development tools such as Cursor, GitHub Copilot, or Claude. Experience with event-driven systems: Kafka, SQS, or similar message queue / stream processing patterns. Familiarity with email delivery pipelines, email authentication standards (DMARC, DKIM, SPF), or email security products. Exposure to multi-tenant SaaS architectures or enterprise integrations (M365, Google Workspace APIs). Experience improving service reliability, observability, and operational tooling in production systems. Prior work in cybersecurity, email security, or compliance-adjacent domains. Ready to be part of AI transformation at Keystone AI Security? Apply Now! #LI-FS1 Keystone AI AI is an equal opportunity employer. Qualified applicants will receive consideration for employment without regard to race, color, religion, sex, national origin, disability, protected veteran status or other characteristics protected by law. For our EEO policy statement please click here . If you would like more information on your EEO rights under the law, please click here . Apply for this position