Principal Back-End Engineer

Note from the Hiring Manager - Clement

I'm thrilled to welcome a Principal Platform Engineer who will help shape the future of our infrastructure. Our platform is strong and reliable, but we’re entering a new chapter where we’ll rethink how we build, scale, and bring AI into our work.

What makes this team special is our mix of curiosity, pragmatism, and solidarity. We move fast while staying thoughtful about quality and impact.

In this role, you’ll help guide our technical direction and make an immediate difference across engineering. If you care about autonomy, mentorship, and building systems that last, we’d love to meet you.

TL;DR

We’re hiring a Principal Platform Engineer to lead backend and platform architecture, lift reliability and developer velocity, and introduce safe, pragmatic AI to speed delivery and quality for thousands of users.

About PhantomBuster

PhantomBuster is a web automation SaaS that allows businesses to grow faster. We enable thousands of companies to boost their growth by finding and connecting with their ideal customers seamlessly.

Founded in 2016, PhantomBuster developed a toolbox of over 120 flows (Phantoms) to help businesses scale their sales and marketing processes. We allow our users to automate finding and enriching data about their potential customers and leverage that data to connect with them.

Today, we are quickly moving from a catalog of automation tools to an AI-powered Sales coach product. We need to empower and expand our technical teams to ensure this transformation is seamless, fast, and powerful.

About the Role and the Team

The Platform team at PhantomBuster is the technical backbone of our SaaS product. We ensure reliability, scalability, developer experience, and performance across our backend and infrastructure.

We run a squad of experienced engineers and tech leads (Joris and Olivier), supported by an Engineering Manager.

We are now hiring a Principal Platform Engineer (IC5) to strengthen the team’s technical leadership, provide a senior partner to our most senior Staff Engineers, and champion the thoughtful use of AI in engineering practices.

This role is critical to maintaining continuity, raising technical standards, and guiding long-term architectural direction.

About the technical stack:

• We use TypeScript with strict rules

• Node and databases as Redis and PostgreSQL

• Cloud-based architecture on AWS

• DevOps tools such as Docker, Ansible

• CI/CD thanks to GitHub Actions and CircleCI

What You’ll Do

Architecture & technical excellence

• Anticipate product and infrastructure needs for growth and reliability

• Set the bar for testing, observability, performance, and security

• Drive code reviews on critical paths, preventing bugs and debt from reaching production

AI adoption & best practices

• Champion AI-assisted engineering: from code generation and testing to debugging

• Establish guardrails for safe and effective use of AI (human review, bias detection, security)

• Identify opportunities to leverage AI internally (developer productivity, monitoring, anomaly detection)

Leadership & mentoring

• Mentor engineers and tech leads, helping them level up

• Share knowledge through workshops, design sessions, and documentation

Cross-team collaboration

• Partner with Product, Frontend, and AI squads to ensure seamless integration and zero-downtime releases

• Lead cross-functional initiatives on reliability, cost optimization, or security

Reliability & incident management

• Play a key role in high-impact incidents, post-mortems, and remediation planning

• Drive improvements in SLOs, alerting, and automation for resilience

Innovation & technical scouting

• Explore new technologies (cloud, orchestration, AI/ML pipelines)

• Propose POCs to validate technical opportunities

Who You Are

Experience & seniority

• 8–12+ years in backend/infrastructure engineering, ideally in SaaS at scale

• Proven track record in a Staff, Principal, or senior technical leadership role

• Experience leading large, distributed, or high-complexity systems

Technical skills

• Expert in TypeScript / Node.js, PostgreSQL, Redis, and modern caching/queuing systems

• Strong cloud experience (AWS preferred), infrastructure-as-code, containers, and CI/CD pipelines

• Solid grounding in system design, reliability, and security principles

• Strong observability skills (metrics, tracing, logging)

• Familiarity with modern AI/ML stacks: vector databases, embeddings, prompt engineering, LLM-based tools

Soft skills & leadership

• Exceptional communicator, able to explain complex tradeoffs clearly

• Pragmatic decision-maker balancing speed, quality, and sustainability

• Collaborative, approachable, and proactive in mentoring

• Strong ownership mindset, with the ability to anticipate risks and unblock others

Nice to have

• Experience with AI/ML production systems (model serving, evaluation pipelines)

• Experience with frontend frameworks (React) or full-stack development

• Contributions to open-source or technical publications

• Hands-on experience in cloud cost optimization or security hardening

What Success Looks Like (First 6–12 Months)

• Developer experience: CI runs about 30% quicker, and PR‑to‑prod time drops about 25%.

• Observability: 50% fewer noisy alerts and tracing on 80% of critical paths, with clear, actionable dashboards.

• Clear Platform direction: a 12–18 month roadmap and three approved decision records that unlock scale, cost, or security wins.

What's in it for you?

• Fully remote working environment.

• Freedom to make an impact at a small, self-funded, and profitable tech startup by laying the foundation for machine learning and AI.

• Working with a very talented team of Engineers. 

• Collaborative and open-minded culture based on rationality, humility, honesty, and long-term thinking.

• Benefits and perks are described below.

Recruitment Process

• Screening with our Talent Acquisition Partner, Jakub (45 min).

• Job Fit interview with the Platform Engineering Manager, Clément (60 min) + a Platform team member.

• Technical Case & Debriefing with Mehdi, our Principal Back-end Engineer, + a Platform team member (60 min).

• Cultural fit interview with two Colleagues from other departments (60 min).

AI Guidelines

At PhantomBuster, we use AI tools daily to build things faster. As the use of AI in recruitment might have multiple implications, we want to be transparent about how we might use it and how we expect you to use it during our recruitment processes.

How we use AI:

• Draft and refine job descriptions and case studies,

• Draft emails during the process,

• Find interview timeslots,

• Summarize interview notes,

How we don't use AI:

• Assess your CV or profile,

• Evaluate interview performance,

• Conduct interviews,

• Grade technical tasks or case studies.

You interact with humans. Period.

We invite you to use AI throughout the recruitment process. However, we want to meet YOU, not machine-generated responses. Your unique perspective matters so much more than perfect AI answers.

Feel free to use AI to:

• Research our company, team, or product,

• Refine your CV, portfolio, or LinkedIn profile,

• Prepare for interviews and brainstorm potential questions,

• Polish your case study or presentation,

• Draft emails to us,

Let us know throughout the process how you used AI - we are curious to learn.

Don't use AI to:

• Search for answers during interviews (unless we ask),

• Create documents (CV, portfolio, presentation) from scratch without your input,

• Build case studies or technical tests without your personal touch.

If you have any questions, we would love to hear from you → jakub.ossowski@thephantomcompany.com