Senior II Product Engineer

Overview

As Senior Engineer II at 9fin, you own significant backend systems that power a rapidly growing debt markets platform. You will lead multi-sprint initiatives, shape scalable architecture, and mentor peers while collaborating with Product, Data, Editorial and Legal domains. You’ll tackle distributed systems challenges under real production load and push for high-quality, observable services. This is an opportunity to help scale a category-defining platform used by top financial institutions with AI-assisted engineering.

Pay / Benefits

• Competitive salary
• Pension with employer matching
• Private medical insurance
• Paid sick leave with income protection
• Group life assurance
• Hybrid working model

Responsibilities

• Own design and delivery of major backend systems across a product domain, from data modelling to API surface and operations
• Lead complex, multi-sprint initiatives involving multiple engineers and stakeholders
• Drive scaling with bottleneck identification, architectural changes, and safe production migrations
• Make pragmatic distributed-systems decisions on consistency, idempotency, partitioning, retries, and observability
• Contribute to platform-level discussions on service boundaries and data ownership as new markets enter
• Run thorough code reviews, mentor engineers, and uphold code quality standards
• Collaborate with Product, Data Engineering, editorial and legal teams to scope work and ship impactful features
• Improve developer experience through tooling, testing, observability, and streamlined processes
• Tackle legacy areas with high-leverage cleanups without delaying delivery
• Utilize AI-assisted engineering to accelerate understanding, prototyping, and shipping code

Key requirements

• Senior backend engineer with end-to-end technical leadership experience across a product domain
• Experience designing distributed systems with production realities: failure modes, observability, data consistency, graceful degradation
• Proven track record of solving scaling problems (DB scaling, throughput, latency, cost) with end-to-end example
• Experience in event-driven architectures (queues/streaming) with clear delivery guarantees and idempotency
• Strong API design, service boundaries, and data flow from storage to clients
• Strong Python experience with modern frameworks (FastAPI, Pydantic, typing)
• Deep SQL and relational data modelling knowledge
• Excellent collaboration and ability to explain complex systems to non-technical stakeholders
• Product and customer mindset balancing shipping value with long-term health
• High standard for code quality, testability, and operational maturity; mentorship focus

• collaboration and cross-functional communication
• mentorship and leadership
• problem solving under production constraints
• Python (FastAPI, Flask, Pydantic, typing)
• PostgreSQL and relational data modelling
• AWS (Lambda, cloud services)

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