Senior Software Engineer | Product Foundations

Stack

Responsibilities

• ▹Design, build and operate backend services in Go that other teams and customers depend on being correct
• ▹Own features end-to-end from design through implementation, testing and production rollout
• ▹Debug complex production issues involving security-, money- or trust-critical flows
• ▹Collaborate with product and other engineering teams to solve problems that don't have textbook solutions
• ▹Contribute to product direction and backlog
• ▹Participate in the on-call rotation for teams that require it

Requirements

• ▹Strong software engineering fundamentals: clean abstractions, maintainable code, justified architecture choices
• ▹Production experience with Go (strongly preferred), or strong systems programming skills in a comparable language
• ▹Experience building or operating trust-critical systems at scale (authentication/authorization, billing, financial data)
• ▹Good understanding of API design best practices: versioning, backward compatibility, auth, idempotency, async patterns
• ▹Strong debugging, optimization and performance-tuning skills, including query profiling, index design and database tuning beyond ORM usage
• ▹Experience operating and optimizing systems under high load
• ▹Hands-on experience with Kubernetes (pods, services, deployments)
• ▹Experience with AI coding agents and agentic development workflows
• ▹Having personally driven a complex project end-to-end
• ▹Strong English skills, verbal and written
• ▹Startup mindset: adaptable, proactive, comfortable with ambiguity

Nice to have

• ▹Multi-tenant identity system design: authentication, authorization, SSO
• ▹Enterprise identity protocols: SAML, OIDC and SCIM
• ▹Billing, audit-trail, notification or feature-flag systems in production
• ▹Cloud provider pricing/billing APIs (AWS, GCP, Azure) or tracking Spot instance availability
• ▹High-cardinality time-series ingestion and querying at scale
• ▹Understanding of Kubernetes internals
• ▹CI/CD and DevOps practices
• ▹Observability tooling (Prometheus, Grafana, OpenTelemetry) in production

Soft skills

What we offer

• ▹Competitive salary (€6,500 – €9,000 gross, depending on experience) plus separate compensation for on-call
• ▹Flexible, remote-first global environment
• ▹Equity options
• ▹Fast feedback loop, most features ship in 1 to 4 weeks
• ▹10% of work time for personal projects or self-improvement
• ▹Learning budget including international conferences and courses
• ▹Annual hackathon
• ▹Team-building budget and company events
• ▹Equipment budget
• ▹Extra days off
• ▹Onboarding trip to Vilnius with travel costs covered

About the company

Cast AI is an automation platform that operates cloud-native and AI infrastructure at scale, embedding autonomous decision-making into Kubernetes and cloud environments. Over 2,100 companies use it; it operates across 34 countries and is headquartered in Miami.