Senior Backend Engineer – Proxmox / Virtualization Platform

Client: Enterprise Data Protection & Backup Solutions (Infrastructure & Virtualization)
Location: Remote (EU only)
Allocation: Full-time · 3 - 4 months (100% focus)

Role Overview

We are looking for a Senior Backend Engineer to join a project focused on building and maintaining robust backend integrations with an enterprise-grade virtualization platform used in mission-critical environments.

This is not an MVP and not a fast-delivery project. The primary focus is performance, reliability, stability, and code quality.
You will work with well-defined APIs and written requirements, in a context where testing and predictability are mandatory.

We are explicitly looking for engineers, not task-oriented programmers - and not profiles that rely on AI tools to generate solutions without understanding the underlying problem.

What You'll Do

Backend engineering & integration

• Implement and maintain backend integrations using REST APIs (OpenAPI 3).
  
  

• Work on clearly defined interfaces and requirements.
  
  

• Ensure deterministic, stable, and predictable system behavior.

Performance, reliability & quality

• Design solutions with strong attention to performance, concurrency, and resource usage.
  
  

• Maintain minimum 80% test coverage, with a strong focus on unit testing (integration testing handled externally).
  
  

• Proactively identify edge cases, failure scenarios, and system risks.

Engineering discipline

• Participate in strict and thorough code reviews.
  
  

• Work within a CI/CD environment (Jenkins).
  
  

• Produce concise technical documentation when required (decisions, trade-offs, constraints).

Responsibilities

• Deliver high-quality, well-tested backend code.
  
  

• Prioritize long-term reliability over short-term delivery speed.
  
  

• Work autonomously with minimal supervision.
  
  

• Communicate progress, risks, and limitations clearly.
  
  

• Actively participate in technical meetings (camera on).

Profile

• ~8+ years of experience in backend development, with strong exposure to multiple projects and technical contexts. Depth of experience and variety of challenges are valued over years alone, as they enable stronger problem-solving and better architectural decisions.
  
  

• Strong experience with Java or Go (Rust acceptable if used pragmatically).
  
  

• Solid background designing and consuming REST APIs.
  
  

• Strong quality mindset: testing, maintainability, and stability first.
  
  

• High autonomy and ownership.
  
  

• Fluent in English (spoken and written).

Must-Have

• Hands-on experience with virtualization platforms, ideally Proxmox, or closely related technologies (e.g. VMware, KVM-based platforms, hypervisor-level integrations).
  
  

• Experience building enterprise-grade systems.
  
  

• Strong unit testing culture.
  
  

• High attention to performance and reliability.
  
  

• Comfortable working without structured onboarding.
  
  

• Availability for full-time focus during the project.
  
  

• Engineering discipline:
  
  

  • Strong testing culture: candidates must be used to writing and maintaining their own tests (unit tests at a minimum).
    
    

  • Clear ownership of quality - “it works on my machine” is not acceptable.
    
    

  • Preference for predictable, well-tested delivery over fast but fragile solutions.
    
    

  • Comfortable defending code quality in strict code reviews.
    
    

  • Experience working in teams where quality gates and code reviews are taken seriously.
    
    

  • Strong bias toward reliability and maintainability over delivery speed.
    
    

  • Accountability mindset: bugs and regressions are owned, not externalized.

Culture & team fit

• Strong bias toward execution and impact.
  
  

• Pragmatic decision-making.
  
  

• Curiosity and willingness to explore unknown territory.
  
  

• Hands-on mentality - everyone builds.
  
  

• Fast, smart, low-ego team.
  
  

• Direct feedback and continuous learning.

What success looks like

After 1 month

• Full understanding of the system and API contracts.
  
  

• High-quality code delivered with strong test coverage.
  
  

• Clear autonomy and ownership demonstrated.
  
  

After 3 - 4 months

• Stable, predictable, and validated integration in production.
  
  

• No rework due to quality issues.
  
  

• High confidence from stakeholders in the technical output.

READY TO APPLY?

Send us your CV to people@scailution.com with the subject: Senior Backend Engineer – Proxmox / Virtualization Platform — {Your Name}