Senior Software Engineer - Billy Team

Why Cast AI?

Cast AI is the leading Application Performance Automation (APA) platform, enabling customers to cut cloud costs, improve performance, and boost productivity – automatically.

Built originally for Kubernetes, Cast AI goes beyond cost and observability by delivering real-time, autonomous optimization across any cloud environment. The platform continuously analyzes workloads, rightsizes resources, and rebalances clusters without manual intervention, ensuring applications run faster, more reliably, and more efficiently.

Headquartered in Miami, Florida, Cast AI has employees in more than 32 countries worldwide and supports some of the world’s most innovative teams running their applications on all major cloud, hybrid, and on-premises environments. Over 2,100 companies already rely on Cast - from BMW and Akamai to Hugging Face and NielsenIQ.

What’s next? Backed by our $108M Series C, we’re doubling down on making APA the new standard for DevOps and MLOps, and everything in between.

About the role

Automation is our superpower and lies at the core of everything we do at Cast. We create solutions that drive efficiency by combining cutting-edge automation with deep Kubernetes expertise.

Behind every product feature our customers love, there’s a powerhouse of engineering excellence making it all possible. That’s where the Billy Team comes in.

The Billy Team builds the critical foundations for day-2 operations—everything that happens after customers adopt Cast AI. From reliable billing and audit trails to notifications and internal feature flags, we ensure the platform runs smoothly, transparently, and at scale every single day.

Why It Matters ?

The Billy Team is the backbone of CAST AI. Our mission is clear: to deliver the essential services that make Cast AI ready for real-world operations, beyond day one. When customers receive accurate invoices, when engineers safely roll out new features, when clusters send the right alerts—it’s because of us.

Requirements:

• Strong software engineering skills with experience in distributed systems and backend development (ideally GoLang, but not a hard requirement as long as you’re willing to transition to it)
• Strong debugging, optimization, and performance-tuning skills
• Experience using and configuring feature flag systems like Flagd, LaunchDarkly, or simillar is not a hard requirement but gives an advantage.
• Experience integrating platforms with payment providers such as Stripe or AWS/GCP/Azure SaaS marketplaces. Not a hard requirement, but it gives an advantage.
• Strong English skills, both verbal and written
• You have to be physically in any of the European countries, GMT +0 to GMT +3
• Ability to work independently and collaboratively within a team
• A proactive, problem-solving mindset with a “yes, we can” attitude.

Responsibilities

On the Billy Team, you’ll work on the core features that keep the Cast AI platform connected and running smoothly:

• Billing Systems – Owning everything from cloud SaaS marketplace integrations to platform usage tracking to internal invoicing.
• Internal Feature Flags – Giving our engineering teams the agility to innovate and ship features safely.
• Notification Systems – Empowering customers with real-time visibility into critical events happening in their Kubernetes clusters and our platform in general.
• Audit Systems – Building end-to-end auditing, from Kubernetes cluster activity to user trails, ensuring transparency and trust.
• Admin API - Enabling customer support and internal teams to work efficiently and deliver a great customer experience.

What’s in it for you?

• Competitive salary (€6,500 - €9,000 gross, depending on the level of experience)
• Enjoy a flexible, remote-first global environment.
• Collaborate with a global team of cloud experts and innovators, passionate about pushing the boundaries of Kubernetes technology.
• Enjoy a flexible, remote-first global environment.
• Equity options.
• Get quick feedback with a fast-paced workflow. Most feature projects are completed in 1 to 4 weeks.
• Spend 10% of your work time on personal projects or self-improvement.
• Learning budget for professional and personal development - including access to international conferences and courses that elevate your skills.
• Annual hackathon to spark new ideas and strengthen team bonds.
• Team-building budget and company events to connect with your colleagues.
• Equipment budget to ensure you have everything you need.
• Extra days off to help maintain a healthy work-life balance.