Senior Software Engineer – Product Foundations

About the role

Cast AI is building the trust and accounting layer for its autonomous cloud‑native platform. As a Senior Software Engineer you will design and ship critical backend services that ensure accurate billing, authentication, and real‑time pricing across multiple clouds.

Key responsibilities

• Design, develop, and operate high‑performance Go services that power authentication, authorization, billing, and pricing features.
• Own features end‑to‑end, from architecture and implementation to testing, production rollout, and on‑call support.
• Debug and resolve complex production incidents affecting security‑critical or financial flows.
• Collaborate with product, design, and other engineering teams to shape solutions for non‑standard problems.

Required profile

• Strong software engineering fundamentals with a focus on clean abstractions and maintainable code.
• Production experience in Go or comparable systems‑programming language.
• Hands‑on experience building trust‑critical systems such as authentication, billing, or financial data pipelines.
• Proven ability to drive complex projects from concept to delivery.
• Excellent English communication skills and a startup‑mindset.

Required skills

• Go programming language
• Kubernetes (pods, services, deployments)
• Cloud platforms: AWS, GCP, Azure
• Infrastructure as Code: Terraform
• Databases: PostgreSQL, ClickHouse
• Messaging & APIs: gRPC, REST, GCP Pub/Sub
• Observability: Prometheus, Grafana, Loki, Tempo
• CI/CD & GitOps: GitLab CI, ArgoCD

What we offer

• Competitive salary (€6,500 – €9,000 gross per month) plus on‑call compensation.
• Remote‑first work environment with occasional travel to Vilnius for onboarding.
• Equity options and a fast‑paced development cycle.
• Learning budget, personal project time, and annual hackathon.
• Team‑building events, equipment budget, and extra days off.