Full Stack Engineer

Certus Sales Recruitment; Greater London; Hybrid; GBP 110,000 - 130,000; Full time

Job summary

Certus Recruitment in London is seeking a Senior Full Stack Software Engineer to power back-office ledger and accounting software at a fintech scale. The role involves building the core transaction infrastructure, ensuring auditable records, and integrating traditional financial systems with blockchain settlement.

You will own backend services, double-entry accounting logic, reconciliation, and settlement workflows, while collaborating on APIs and event schemas. Hybrid work model offered.

Qualifications

• 5+ years' professional software engineering experience.
• Proven experience building back-office ledger/accounting software.
• Strong experience with financial transactions, reconciliation and data integrity.
• Experience taking systems from prototype through to production.
• Strong back-end engineering capability.
• Experience with strongly typed languages.
• Strong SQL/PostgreSQL knowledge.
• TypeScript experience.
• Rust experience would be highly valuable, though other systems languages considered.
• Experience with event-driven architectures and transactional systems.
• Strong written communication and a design/documentation-led approach.

Responsibilities

• Back-end services and transaction workflows.
• Double-entry ledger and accounting systems.
• Settlement services and payment orchestration.
• Event-sourced financial records.
• Reconciliation and transactional integrity.
• Compliance and authorisation logic.
• Database design and integrity controls.
• Shared APIs and event schemas.
• Customer-facing and internal applications.
• Integration between traditional financial infrastructure and blockchain settlement.

Skills

Back-end engineering

SQL/PostgreSQL

Event-driven architectures

TypeScript

Rust

Strong typed languages

Documentation & design

Financial data integrity

Job description

Full Stack Software Engineer – Back Office Ledger/Accounting Software

London – Hybrid, 2 days per week

£110,000–£130,000 + benefits

Certus Recruitment is working with an ambitious UK fintech building a new regulated digital currency and payments platform.

We are looking for a Senior Software Engineer to play a key role in taking the platform from its current stage through to regulated, production-grade deployment.

This is a highly hands‑on engineering role, working across the application and protocol layer and building the services and core engines responsible for issuing, recording, reconciling and settling financial transactions.

The key requirement

We are particularly interested in engineers who have built back‑office ledger or accounting software.

You should have experience developing systems where financial transactions must be recorded accurately, balances must reconcile and there is a clear, auditable record of every movement of money.

Experience could come from payments, banking, fintech, accounting platforms, custody, financial infrastructure or another environment where transactional and accounting correctness is critical.

The role

You will take ownership across areas including:

• Back‑end services and transaction workflows
• Double‑entry ledger and accounting systems
• Settlement services and payment orchestration
• Event‑sourced financial records
• Reconciliation and transactional integrity
• Compliance and authorisation logic
• Database design and integrity controls
• Shared APIs and event schemas
• Customer‑facing and internal applications
• Integration between traditional financial infrastructure and blockchain settlement

This is very much a build role. You will be taking architecture and design documentation and turning it into robust, auditable production software.

What we're looking for

• 5+ years' professional software engineering experience
• Proven experience building back‑office ledger/accounting software
• Strong experience with financial transactions, reconciliation and data integrity
• Experience taking systems from prototype through to production
• Strong back‑end engineering capability
• Experience with strongly typed languages
• Strong SQL/PostgreSQL knowledge
• TypeScript experience
• Rust experience would be highly valuable, although strong engineers from other systems languages who are keen to learn Rust will be considered
• Experience with event‑driven architectures and transactional systems
• Strong written communication and a design/documentation‑led approach

Experience within payments, banking, fintech, custody or digital assets would be particularly relevant.

Blockchain or stablecoin experience is not essential, but you should be interested in developing your knowledge of on‑chain systems and comfortable working in a highly regulated financial environment.

The opportunity

This is an opportunity to join at a genuinely formative stage and help build the core financial infrastructure behind a new regulated platform.

Rather than maintaining an established product, you'll be directly involved in building the ledger, settlement and transaction infrastructure that ultimately needs to demonstrate that every movement of money is correct, reconciled and auditable.

£110,000–£130,000 + benefits

Hybrid – 2 days per week in London