Staff Backend Engineer (Ruby) M/F/Mx

Trustpair stops vendor fraud before it happens. We're the automated vendor validation platform protecting 400+ enterprise companies worldwide. Since 2017, finance and procurement teams have used Trustpair to eliminate vendor fraud while reclaiming 90% of the time they once spent on manual checks.

As vendor fraud grows more sophisticated, we stay ahead by combining deep expertise in financial crime with cutting‑edge technology. Our core product focuses on secure, reliable vendor account validation to wipe out fraud and boost efficiency.

Internally, teams across Trustpair use AI tools in their day‑to‑day work to automate repetitive tasks and unlock strategic insights that help us build and operate better. From day one, you’ll be encouraged and trained to integrate these tools into your workflow in a practical, hands‑on way.

With offices in New York, Paris, London, and Milan, we’re a diverse team united by a bias for action. We ship fast, learn from experiments, and tackle problems that matter: protecting billions in payments for companies worldwide. If you want to see your work make an immediate impact in financial security, Trustpair is built for you.

About The Role

As a Staff Software Engineer on our Core Evaluation team, you will be a technical authority driving the evolution of our most critical asset: the fraud detection engine. This is a pivotal role where you'll not only architect for scale and resilience, but also spearhead the integration of LLM‑based insights to rethink our evaluation process. You will be entrusted with our most complex and ambitious projects, shaping advanced solutions from ambiguous requirements. Working within a dedicated squad, you will collaborate closely with your Engineering Manager, Product Manager, and fellow engineers to turn a strategic vision into a technical reality that further strengthens Trustpair’s position as a market leader.

Location: Paris (hybrid), or full remote in France.

What You’ll Do

• Architect and own the technical vision for large‑scale distributed systems at the heart of our platform, focusing on complex evaluation workflows.
• Lead complex, cross‑functional technical projects from conception to completion, ensuring alignment with product strategy and client needs.
• Partner with Product and Engineering leadership to build and refine the technical roadmap, identifying key challenges and proposing innovative solutions that drive business forward.
• Champion a culture of innovation and continuous improvement, directly involved in transforming the Trustpair engine by exploring and implementing new technologies, especially LLM‑based solutions.
• Act as a technical mentor and force multiplier for engineers within your squad and across the organization, promoting best practices in software architecture, design, and strategic thinking.
• Promote and implement best practices for observability, scalability, and performance, ensuring our core systems are reliable and efficient.

What’s in it for you?

• High impact in a high‑growth environment: join a company with 50%+ business growth where technology accelerates success.
• Influence critical architectural, product, and organizational decisions during scale‑up.
• Work with a modern Ruby on Rails stack, state‑of‑the‑art DevOps, and growing AI adoption.
• Full engineering ownership and accountability for initiatives from design to impact.
• Accelerated career growth, skill development, and leadership opportunities.
• Collaborative and international team culture.

Why join Trustpair?

Explore our full list of perks and benefits.

Must Haves

• Mission‑driven and customer‑focused.
• Eight or more years of experience in high‑throughput environments, with at least 2–3 years in Ruby on Rails.
• Proven track record of architecting, building, and operating complex, large‑scale systems, especially asynchronous workflows.
• Hands‑on experience with observability tools such as Datadog, Prometheus, or Grafana.
• Strong DevOps mindset and experience scaling and tuning applications on Kubernetes.
• Deep expertise in performance analysis and optimization for application code, databases, and infrastructure.
• Excellent communication and collaboration skills, effective in agile teams and influencing direction without direct authority.
• Continuous learner who keeps a technical watch on evolving ecosystems and applies best practices creatively.

Bonus Points

• Direct experience designing, building, and deploying LLM‑powered applications.
• Experience in a high‑growth B2B SaaS environment.
• A data‑driven approach to decision‑making from product analytics to application monitoring.

Equal Opportunity Statement

Trustpair’s policy is to provide equal employment opportunity in all employment practices without regard to race, color, religion, sex, national origin, ancestry, marital status, veteran status, age, disability, sexual orientation, or gender identity or expression.

Applicants for all positions in Trustpair must be legally authorized to work in the country they are applying for, or be a citizen of the Schengen/EU zone. Verification of employment eligibility will be required as a condition of hire.