Senior Backend Engineer: Java & Python API Systems

S3tel. Inc. is seeking a Senior Backend Developer to design, build, and maintain scalable backend services using Java/Spring Boot and Python for modern web, mobile, and integrations.

You will own APIs, database design, service architecture, and production stability, collaborating with cross‑functional teams and mentoring juniors. The role emphasizes reliable, secure, and well‑documented code and fast, fault‑tolerant backend systems.