About the role
Behind every Kernel account is a Kiwi working towards something: a first home, a comfortable retirement, or just a bit more freedom. They trust us with their savings, and the systems you build are how we keep that trust.
This is a big moment for engineering at Kernel. We're modernising the systems that got us here, bringing core capabilities in-house and building for many more Kiwis. We need experienced engineers to help make the big technical calls, and to help a growing team do its best work.
As a Senior Software Engineer, you'll own the design, delivery and health of key backend systems, contribute to technical direction across the platform, and coach the engineers around you. You'll join a team of 3–5 engineers, work closely with Product and Design, and report to your Engineering Manager. This isn't a people management role: your impact comes from your technical judgement and how you raise the bar. It's based in our Auckland office, with at least 3 days a week on site.
About Kernel
We're a 100% Kiwi owned and operated fintech on a mission to make wealth accessible for every Kiwi. Our investment platform brings together KiwiSaver, Managed Funds, US shares and ETFs, and Smart Saver accounts, all in one place, and is trusted by 80,000+ investors.
We're at an exciting stage: scaling fast, expanding our team and building the foundations for what's next. Our culture is collaborative, hands-on and ambitious, built on trust, innovation and saying it like it is. Things move quickly here, and every person plays a key role in shaping our future.
Engineering at Kernel
What you'll build
• Services that move and track real money, where being right matters more than being first
• Core financial capabilities we're bringing in-house, so we own more of what happens to every dollar
• Reliable connections to the banks, fund managers and partners behind every transaction
• The systems that got us here, reshaped to scale with more teams and more customers
• Shared platform services that every product team builds on
How we build
• C# and .NET, written in a functional style that puts correctness, clarity and testability ahead of clever shortcuts
• Almost entirely serverless on AWS: event-driven services on Lambda, with DynamoDB at the core
• GitHub and GitHub Actions for CI/CD, with infrastructure as code on our roadmap
• AI-native by default: everyone gets a Claude licence, paid for by Kernel, and we build with Claude Code every day, so more of the job is design, trade-offs and making sure what ships is right
• Correctness over speed: when it's people's savings, a clear "service unavailable" beats a wrong number every time
How we work
• Small, stream-aligned teams of 3–5 engineers, each focused on one area of the platform
• Plan properly up front to surface risks, then deliver in small milestones that each add real value
• Work in 1–2 week cycles with regular check-ins and retros, not rigid sprints or long release plans
• Ship as often as we can, using feature flags where needed
• Engineers own quality, with QAs who coach and advocate rather than test for you
• Pairing, mobbing and whiteboarding are part of everyday work
What you'll do
• Design, build and operate backend services, APIs and integrations in C# and .NET on AWS
• Own the design, delivery and ongoing health of key systems, balancing scalability, security, performance and maintainability
• Shape architecture and technical decisions across multiple systems, including how they evolve as we add more teams
• Design event-driven, serverless solutions and DynamoDB data models around real access patterns
• Plan for failure: retries, idempotency, third-party outages and what customers see when something goes wrong
• Set the standard for testing, observability and code quality, and lead by example in production
• Mentor and coach other engineers through pairing, code reviews and whiteboarding
• Lead the way on building well with AI, using Claude Code every day while keeping quality and accountability high
• Partner with Product and Design on scoping and feasibility, turning customer problems into well-built solutions
You'll be great if you bring
• Strong commercial experience designing, building and running backend systems in production
• Deep C# and .NET skills, and an interest in functional programming concepts
• Hands-on serverless, cloud-native experience, ideally on AWS (strong Azure experience counts too)
• Experience with NoSQL databases such as DynamoDB, and comfort designing data around access patterns
• A strong grasp of distributed and event-driven systems, API design and the trade-offs of building for scale
• A track record of owning systems in production, including incidents and what you learned from them
• Experience mentoring engineers and lifting the quality of a team's work
• Everyday use of AI coding agents, with the judgement to know when to trust them and when to dig deeper
• The ability to explain and defend a design clearly, whether at the whiteboard or in a pull request
• Comfort with ambiguity and high ownership in a growing team, where one person can change how things are done
Bonus things you could bring
• Hands-on functional programming experience, in F#, C# or another language
• Experience in payments, banking, ledgers or other regulated financial systems
• Experience breaking larger systems into well-bounded services, and knowing when not to
• Experience pushing the limits of agentic workflows and AI-driven engineering
• Infrastructure as code, such as Terraform, and CI/CD pipelines such as GitHub Actions
Why you'll love it at Kernel
• Help shape a platform and an engineering culture at a pivotal stage, while the big decisions are still being made
• Work on hard problems with real stakes, where the systems have to be right because people's savings depend on them
• Grow your impact and your career as the team scales, with clear engineering levels beyond Senior
• Join a team built on trust, collaboration and flexibility, where feedback is constructive and everyone has a voice
• Competitive pay, reviewed annually, plus an annual performance bonus
• Enjoy the best of both worlds with a flexible hybrid setup: connect in person while keeping the freedom to work from home up to a couple of days each week (minimum 3 days a week in the office)
• Southern Cross health insurance that covers pre-existing conditions, with discounted cover for your family
• A 13-week parental leave top-up to full pay, and free, confidential wellbeing support through our EAP
• Professional development support and a learning budget
• Extra Kernel holidays, office snacks, coffee and a dog-friendly office
Join our team
Not sure you meet every requirement? We encourage you to apply. We value growth, impact and mindset just as much as specific experience.
To be considered, you'll need the right to work in New Zealand and to be based in Auckland, or already relocating here.
If this opportunity sounds like you, send us your cover letter explaining why you're excited about the role and working at Kernel, along with your CV.
Visit our careers page for more on working at Kernel and follow us on LinkedIn & Instagram. to stay connected.