Senior Backend Engineer

Saturn; Greater London; On-site; GBP 90,000 - 140,000; Full time

Benefits offered by this job

Competitive salary

Equity package

Office: The Dome

Private medical & dental insurance

Learning & development budget

Wellness centre access

High ownership & autonomy

Job summary

Saturn is seeking a Senior Backend Engineer to own substantial backend systems and platform capabilities, from design through reliable production operation. You will collaborate with product, AI engineers and leadership to turn complex financial and regulatory problems into durable systems.

You will shape architecture, make informed trade-offs with incomplete specs, and help Saturn become a coherent platform that scales with business needs.

Qualifications

• 4+ years shipping customer-facing software in production.
• Experience owning a substantial product area from ambiguous problem to adoption.
• Strong frontend engineering depth in TypeScript and modern web frameworks.
• Strong full-stack capability across systems with good judgment.

Responsibilities

• Own substantial backend systems and platform capabilities from design to production operation.
• Collaborate with product, AI engineers and leadership to turn complex problems into durable systems.
• Make engineering trade-offs when complete specifications are unavailable.
• Guide architectural decisions and contribute to shared foundations.

Skills

Backend engineering

Product ownership

Frontend depth (TypeScript)

Full-stack capability

Architecture decisions

Communication & documentation

Mentoring engineers

Startup pace & judgement

Tools

TypeScript

Web frameworks

Design systems & frontend platform

Job description

Your role

As a Senior Backend Engineer, you will own substantial backend systems and platform capabilities from design through to reliable production operation.

As a Senior Backend Engineer, you will own substantial backend systems and platform capabilities from design through to reliable production operation.

You will work closely with product engineers, AI engineers, domain experts and engineering leadership to turn complex financial and regulatory problems into durable systems.

You will not wait for every problem to arrive as a complete technical specification. You will be expected to understand the business objective, identify the important constraints and make sound engineering trade-offs.

Your work will help determine whether Saturn becomes a collection of useful applications or a coherent platform capable of supporting increasingly important financial workflows.

What We're Looking For

• 4+ years building and shipping customer-facing software in production
• Experience owning a substantial product area from an ambiguous problem through to adoption and iteration
• Strong frontend engineering depth in TypeScript and modern web frameworks
• Strong full-stack capability, with the judgement to work across the system where needed
• Experience contributing to frontend architecture and shared engineering foundations
• A record of making product decisions without relying on complete specifications
• Strong product judgement and the ability to explain trade-offs clearly
• Experience working closely with design while maintaining technical ownership
• Evidence of improving performance, accessibility and interaction quality in production products
• Experience building reliable interfaces around complex data, workflows or permissions
• Experience investigating production issues and translating findings into product improvements
• A record of scoping and delivering work measured in months from a business or customer objective
• Strong written communication, with the ability to document product and technical reasoning
• Experience improving standards across code review, testing, release and client-facing quality
• Comfort owning decisions with incomplete information and real deadlines
• Experience mentoring engineers and improving the quality of a team
• Experience working at startup pace without sacrificing judgement or craft

Preferred Experience

• Building software for financial services, healthcare, legal or another regulated domain
• Financial advice, wealth management or investment products
• Building AI-native products or interfaces around probabilistic systems
• Designing human review, approval or exception-handling workflows
• Mobile product development
• Complex forms, document workflows or data-heavy applications
• Design systems and frontend platform architecture
• Building enterprise products with sophisticated permissions and firm-specific configuration
• Accessibility standards and performance optimisation
• Taking a product from early adoption to broad production use

What Success Looks Like

Success in this role means:

• advisers can complete more of their working day inside Saturn
• complex workflows become simpler without losing regulatory control
• product decisions are grounded in evidence and clear reasoning
• client-facing engineering moves quickly without accumulating avoidable inconsistency
• the web and mobile experience feels coherent across products
• performance, accessibility and interaction quality improve as the product scales
• production issues are understood quickly and influence what gets built next
• engineers increasingly build on shared foundations rather than fragmented product patterns
• advisers trust Saturn with increasingly important parts of their work
• the product becomes harder to replace because it is deeply integrated into how firms operate
• Saturn develops a strong product engineering culture with a high bar for craft, ownership and judgement

The team

Our engineers care deeply about craft, speed and quality. They include early and founding team members from companies including Rippling, Postman, Gojek, CRED and Slice.

You will work alongside product designers, backend engineers, AI engineers and domain experts with decades of experience in financial advice and compliance.

We are building a small, high-calibre engineering organisation for people who want genuine ownership, difficult product problems and the opportunity to shape an important company while its foundations are still being formed.

Our values

We hire people who pursue greatness, care deeply about their work, seek truth over comfort, earn trust rather than assume it, and succeed or fail as one team.

What We Offer

• a competitive salary with regular appraisals
• a competitive equity package in an early-stage company with significant growth potential
• our new five-floor office, The Dome, with an on-site gym and roof terrace
• best-in-class private medical and dental insurance
• a dedicated learning and professional development budget
• access to a world-class gym and wellness centre two minutes from the office
• genuinely difficult problems at the intersection of fintech, regulation and AI
• high ownership and autonomy while building the foundations of a company with a credible path to 50 times revenue growth
• a tight-knit, ambitious team that cares deeply about quality and one another