Senior BackEnd Engineer

💥Senior Backend Engineer💥

Series A AI Fintech | High-growth | Backed by Tier 1 global VCs

📍 London

💸 £100–£200K + Significant Equity (≈$160K vested over 4 years)

Omnis Partners is working with a fast-scaling Series A AI fintech building next-generation workflow infrastructure for global financial institutions.

This is a rare opportunity to join early in the scaling phase and help architect the backend systems powering a production-grade AI platform already deployed with major enterprise clients.

🚀 The Opportunity

As a Senior Backend Engineer, you will play a central role in designing and scaling the core backend architecture behind a high-performance AI platform operating in complex, regulated financial environments.

You’ll collaborate closely with ML engineers, product teams, and infrastructure specialists to build systems that are resilient, secure, and capable of operating at enterprise scale.

This is a hands-on engineering role with real ownership, your decisions will directly influence system capability, scalability, and product direction.

🧩 What you’ll be doing

• Design and build scalable backend services and APIs powering a production AI platform.
• Develop and enhance high-volume data pipelines handling large-scale financial datasets.
• Work with ML engineers to bring machine learning models into production systems.
• Design, optimise, and scale PostgreSQL databases (schema design, indexing, performance tuning).
• Build secure systems aligned with regulatory standards including SOC 2, GDPR, and FCA expectations.
• Contribute to event-driven and distributed system architecture using async processing patterns.
• Improve system reliability, observability, and performance in live production environments.
• Participate in architecture decisions and provide mentorship to other engineers.

🔧 What they’re looking for

• 5+ years backend engineering experience building production systems at scale.
• Strong Python experience (FastAPI, Django, or Flask).
• Deep PostgreSQL expertise, including query optimisation and schema design for scale.
• Strong understanding of distributed systems, microservices, and event-driven architecture.
• Hands-on experience with Redis, caching strategies, and async processing (e.g. Celery).
• Cloud experience (Azure preferred; AWS or GCP also acceptable).
• Experience with Docker, Kubernetes, and modern CI/CD pipelines.
• Strong knowledge of security, authentication, and data protection in production systems.
• Ability to thrive in fast-moving, high-ownership engineering environments.

💡 Why this role

• Significant ownership over backend systems and architectural direction
• Opportunity to build AI infrastructure used in real-world enterprise finance use cases
• Direct access to founders with multiple successful venture-backed exits
• High-growth environment where engineering impact is immediate and visible
• Chance to help define a category-leading AI platform at Series A stage

⚠️The reality

This is not a slow-moving environment.

Priorities shift, complexity is high, and expectations are ambitious.

You’ll need to be comfortable working with autonomy, ambiguity, and rapid iteration.

In return, you’ll get genuine ownership, accelerated learning, and the opportunity to shape a company at a pivotal stage of growth.