Open role

Senior Software Engineer

Apply now
ZeroWarsaw, PolandFull-time

About Us

Zero Hiring is building the AI hiring stack for modern recruiting teams. Our product helps employers run faster, more consistent hiring workflows through AI-led interviews, structured candidate evaluation, and intelligent automation across the recruiting process. We're a small, focused engineering team with paying customers and a product already delivering real value in production. As our platform grows, we're looking for experienced engineers who can help us scale thoughtfully while continuing to ship features that matter.

The Role

We're hiring a Senior Software Engineer to work across our backend systems, AI interview infrastructure, product workflows, and customer-facing features. You'll own critical parts of our product infrastructure—the systems customers depend on every day but may never see directly. This includes reliability, integrations, observability, data consistency, external API boundaries, and the quality of our LLM-driven scoring systems.

This is not a pure platform role. You'll ship product features alongside the rest of the team while strengthening the foundation that supports them. You'll have significant ownership and the opportunity to shape both our technical architecture and product direction.

What You'll Do in Your First 90 Days

  • Improve observability across backend services, interview flows, and AI scoring pipelines to give the team better visibility into system behavior
  • Harden webhook and integration paths to handle idempotency, retries, race conditions, and partial failures gracefully
  • Build regression tests and evaluation workflows for AI scoring, rubric changes, and prompt updates
  • Add timeouts, retry policies, and cost controls around external API calls to improve reliability and manage expenses
  • Ship several customer-facing features across both employer and candidate workflows

What We're Looking For

Required Qualifications:

  • 5+ years of experience building production software with strong backend engineering expertise
  • Proficiency in Python or similar languages, modern web frameworks, PostgreSQL, and asynchronous service design
  • Strong product engineering instincts with a focus on delivering value to users
  • Experience working with webhook-heavy, integration-heavy, or money-adjacent systems where reliability is critical
  • Practical observability experience including structured logging, useful dashboards, tracing, and alerting
  • Fluency with LLM-backed product development: managing prompt changes, structured outputs, regression tests, and navigating latency/cost tradeoffs
  • High agency, strong testing judgment, and clear communication skills
  • At least four hours of overlap with US Eastern time for collaboration with the team

Bonus Experience:

  • Real-time voice, video, WebRTC, or other latency-sensitive systems
  • Recruiting, HR, ATS, CRM, or workflow automation products
  • Billing, payments, subscriptions, or revenue-critical systems
  • Building evaluation frameworks, regression harnesses, or prompt versioning for LLM-powered features
  • Agentic development workflows using tools like Cursor, Claude Code, or similar AI-assisted development environments

Why Join Zero Hiring

You'll join a small, high-impact team working on a product that's already making a difference for real customers. You'll have meaningful ownership over important technical decisions and the opportunity to shape both our engineering culture and product direction. We're building in a space where AI can genuinely improve outcomes—making hiring more fair, consistent, and efficient for everyone involved.

If you're excited about working at the intersection of product engineering, AI systems, and infrastructure reliability, we'd love to hear from you.

Application

Apply for Senior Software Engineer

Zero

Zero Hiring processes the information you provide (including your resume and interview responses) on behalf of Zero to assess your application. Your application may be screened and scored using automated / AI systems. We keep your data as described in our Privacy Policy and you can exercise your privacy rights at privacy@zerohiring.com.

Some screening decisions are made with the help of automated systems. You have the right to request human review of a decision that affects you — contact privacy@zerohiring.com.

Read our Privacy Policy

Senior Software Engineer at Zero