Senior software engineer - 6 month O/IR35

Seccl; United States; Remote; USD 93,000 - 126,000; Full time

Job summary

Seccl is seeking a senior engineer for a remote UK role. You’ll design, build and operate reliable services using TypeScript and Node.js, shaping resilient financial workflow systems across multi‑region environments.

Join a cross‑functional squad, own end‑to‑end delivery, mentor engineers, and contribute to testing, observability and performance. You’ll work with AWS serverless tech and MongoDB, with on‑call duties and a focus on quality, scalability and regulatory considerations.

Qualifications

• Strong experience with Node.js and TypeScript in production
• Experience building in regulated financial services environments
• Familiarity with AWS serverless technologies and observability
• Experience mentoring engineers and leading technical delivery
• On-call experience and incident management understanding

Responsibilities

• Design, build and operate services within your domain
• Own SLAs and drive iterative improvements
• Maintain and extend documentation for services
• Mentor other engineers and share best practices
• Communicate with non-technical colleagues about Seccl system
• Be part of a cross-functional squad with product and operations

Skills

Node.js

TypeScript

AWS

Serverless

MongoDB

Mentoring

Delivery leadership

On-call

Regulated industry

Observability

Tools

Terraform

Serverless Framework

Job description

This role is remote within the UK, and we're looking for engineers available quickly to join us for 6 months under O/IR35 requirements.

About us

Seccl is the Octopus-owned embedded investment platform, on a mission to help more people invest, and invest well.

We’re building the infrastructure behind the next generation of investing. Our technology already powers some of the UK’s most ambitious fintechs, banks, financial advisers and wealth firms, with close to a million investors relying on Seccl-powered platforms. And we’re now expanding into Europe.

We’ve got a proven product, strong momentum and big ambitions for what comes next: helping more household-name brands launch and scale investment propositions, entering new markets and replacing outdated investment infrastructure with technology that’s faster, simpler and built for scale.

We’re proud to be part of Octopus, one of the UK’s most successful privately held investment and technology groups. That gives us the backing and long‑term perspective to build something substantial, while keeping the pace and energy of a high-growth business. Seccl and Octopus are both B Corp certified and share a belief that profit and purpose should go hand in hand.

If you want to help shape the future of investing in the UK and across Europe, you’ll be in good company.

Check out the Seccl website to see what we’re building and read more about our mission to shape the future of investments.

Our culture:

Never settle – We think of ourselves as ‘embedded hero-makers’ for our customers. We put them first, and if we say we’ll do something, we’ll move heaven and earth to do it. We think boldly and embrace change.

Take ownership - We think rigorously and deeply about a problem, but then charge at it, acting with and urgency and speed that sets us apart. But we never lose sight of quality or long-term scalability.

Be generous & candid - We encourage our people – and our customers – to challenge us and never shy away from tough conversations. We have a flat and inclusive culture where everyone can be themselves – and speak up.

Check out our Glassdoor page for the latest reviews or our LinkedIn for company updates and insights from the team.

Our engineering ways of working:

• Our Product and Engineering organisation is structured into four tribes: Custody, Accounts, Experience, and Cloud & Security. Each tribe contains multiple autonomous squads, with clear full ownership over specific product domains.

• The squads are intentionally small and cross-functional, typically made up of an Engineering Manager, Product Manager, and 3–5 engineers with complementary skills aligned to the domain they own.

• We operate in a build-and-run model, with teams responsible for the full software lifecycle, from architecture and delivery through to operational support and incident management.

• Our core platform is built on AWS serverless technologies including Lambda, SQS, EventBridge, API Gateway, S3, and ECS. We primarily develop in TypeScript and Node.js, with MongoDB as our primary document database. We also have a small number of C# services and are continuing to evolve our platform architecture, including expanding our use of ECS Fargate.

• Infrastructure is managed through a combination of Terraform and Serverless Framework. We use GitHub Actions for CI/CD and incident.io to support our incident management processes and operational workflows.

• We care deeply about engineering quality, pragmatic architecture, and continuous improvement. If you’d like to go deeper, we’re happy to share more about our engineering practices and technology radar during the interview process.

The role

As an engineer at Seccl you will design, build and operate reliable and scalable, testable and maintainable software solutions, building new functionalities and products using Typescript and Node.js. You play a key role in our software development and have a hands‑on approach throughout the development process supporting resilient financial workflow systems and regulated investment operations. As a senior member of the team, you are the ‘go‑to’ person for queries.

On a typical day you will…

• Work collaboratively in a domain aligned cross-functional squad made up of engineers and product along with colleagues from customer‑facing and operations teams

• Design, implement and operate your services within your domain

• Be accountable for the SLAs of your products and iterative improvements

• Maintain and extend documentation for your services

• Foster a culture of continuous improvement and technical excellence while understanding when “good enough for now” is appropriate

• Provide guidance and mentorship for other engineers

• Communicate with non‑technical colleagues to answer queries about the Seccl system

What you need…

• To own your services from design to operation. We operate a build‑and‑run model where engineers have autonomy but full accountability.

• We care deeply about correctness, resilience and operational excellence because our systems underpin real customer investments.

• Engineers are not passengers in their products but champions. Drive improvements and features while collaborating openly with product, operations and engineering colleagues, challenging ideas constructively and focusing on delivering the best outcomes for customers.

• Have a strong ability to understand business and customer problems and turn them into efficient, scalable solutions. Be curious about how investment and custody products operate, and pragmatic in balancing customer value, operational correctness, engineering quality and long‑term scalability.

• Experience building financial systems with multi‑region, multi‑currency or trading‑related complexity would be advantageous.

• Experience in a strongly/statically typed language.

• Have a strong understanding of designing, building, and running high‑quality, standards‑compliant workflow APIs, with a focus on testing, observability, and performance.

• Have worked with a cloud provider (AWS/Azure/GCP). We use AWS.

• Have worked with distributed systems and are comfortable debugging through tracing and observability.

• Willing to be on‑call for your services.

Core technical skills you must have:

• Strong commercial experience with Node.js, specifically TypeScript

• Experience with Amazon Web Services

• Experience with Serverless products

• Experience with document databases, ideally MongoDB

• Experience mentoring engineers

• Experience leading technical delivery in a build‑and‑run engineering model

• Experience in a structured on‑call process and incident management

• Experience working in regulated industries, ideally financial services or FinTech.

This role isn’t for you if...

• You rely on a lot of top‑down direction. Here, you’ll have a lot of freedom and ownership of your role, and you’ll be expected to shape your own progression, bring forward ideas, and spot opportunities to improve

• You’re not comfortable working in a fast‑paced environment. Our speed and scalability are what set us apart; you need to be able to act quickly and think on your feet

• You struggle to follow through on ideas. We value people who do what they say they will. If you care about something, you have the freedom here to make it happen

• You don’t like change. You’ll get on great here if you relish the ambiguity of rapid growth and are willing to embrace uncertainty