Senior Software Engineer - Billy Team

Location: Bulgaria; Greece; Hungary; Lithuania; Poland; Romania; Slovakia

Department: Technology

Why Cast AI?

Cast AI is an automation platform that operates cloud-native and AI infrastructure at scale. By embedding autonomous decision-making directly into Kubernetes and cloud environments, Cast AI continuously optimizes performance, reliability, and efficiency in production.

The old way doesn't work. As Kubernetes and AI environments grow, manual decisions don’t. Cast AI replaces tickets, alerts, and manual tuning with continuous automation that adapts infrastructure as conditions change. Efficiency and cost savings follow naturally from that automation.

Over 2,100 companies already rely on Cast AI, including Akamai, BMW, Cisco, FICO, HuggingFace, NielsenIQ, Swisscom, and TGS.

Global team, diverse perspectives
We're headquartered in Miami, but our impact is international. We take a global and intentional approach to diversity. Today, Cast AI operates across 34 countries spanning Europe, North America, Latin America, and APAC, bringing a wide range of perspectives into how we build and lead. 

Unicorn momentum
In January 2026, we achieved unicorn status with a strategic investment from Pacific Alliance Ventures, the corporate venture arm of Shinsegae Group (a $50+ billion Korean conglomerate). Our valuation now exceeds $1 billion, and we're just getting started.

Join us as we build the future of autonomous infrastructure.

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 in GoLang.
• 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.
• 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.

Hiring process

• Screening call with Recruiter
• Hiring Manager interview
• Technical interview (system design)
• Live coding
• Culture Check interview with an executive

*As part of our standard hiring process, we would like to inform you that a background check may be conducted at the final stage of recruitment through our third-party provider, Checkr.
*Please note that Cast AI does not provide any form of visa sponsorship/work permit.

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