Principal Site Reliability Engineer

iwoca; Greater London; Hybrid; GBP 100,000 - 140,000; Full time

Job summary

iwoca is seeking a Principal Site Reliability Engineer to enhance system reliability in their London headquarters or offer remote flexibility within the UK. The role combines technical leadership with hands-on work in data systems, requiring expertise in Kubernetes, PostgreSQL, and infrastructure automation. Candidates should have experience in shaping incident processes and a commitment to reliability principles. The company values a culture of learning and offers generous benefits, including flexible working, medical insurance, and a structured professional development plan, ensuring employees thrive in a dynamic environment.

Benefits

Flexible working

Medical insurance from Vitality

25 days’ holiday plus an extra day for your birthday

A one-month, fully paid sabbatical after four years

3% Pension contributions and share options

Generous parental leave and nursery tax benefit

Cycle-to-work scheme and electric car scheme

Qualifications

• Experience with designing and scaling data-intensive systems essential.
• Deep understanding of site reliability principles important.
• Experience in automation for monitoring and alerting needed.

Responsibilities

• Influence reliability improvements across multiple teams.
• Lead new practices for incident response and reliability.
• Design and implement systems for scalability and performance.

Skills

Experience designing data-intensive systems

Kubernetes

PostgreSQL

AWS RDS

Incident processes

Site reliability principles

Infrastructure automation

Monitoring and alerting

Education

Strong academic background in maths or related field

Tools

Terraform

DataDog

Python

SQL

Go

Job description

Principal Site Reliability Engineer - Core Systems

Hybrid in London or Remote within the UK

The company

Imagine a world where every small business has the power to thrive. That's the world we're building at iwoca. Small businesses aren't just statistics – they're the heartbeat of our communities, the character of our high streets, and the engine of our economy. Since 2012, we've revolutionised how these businesses access finance, turning what was once a lengthy, frustrating process into something remarkable: funding that's fast, flexible, and actually works for modern businesses.

Our impact speaks for itself: we've provided billions in funding to over 150,000 businesses across Europe, making us one of the continent's leading fintech innovators. But we're just getting started. Our mission? To empower one million businesses with the financial tools they deserve.

We combine cutting-edge technology and data science with genuine human understanding to make finance feel less like a barrier and more like a superpower. Whether it's managing cash flow or seizing unexpected opportunities, we ensure businesses get the funds they need – often within minutes.

The team

You’ll join the Core Systems team, who optimise development, build data systems, and continuously improve iwoca products. They follow Agile-inspired processes, using continuous integration and delivery so that features go live in days or weeks, not months or years.

The role

You’ll influence iwoca’s tech strategy to make our systems more reliable and as we get closer to our goal of funding one million businesses. The role will focus on complex data systems and flows that power multiple internal products and services.

Our biggest reliability challenges aren’t sudden spikes in users or data volume - they’re the accumulating complexity, interconnectivity, and constant evolution of these internal systems. So, you’ll need to empathise with different team’s pressures, have a practical, problem-solving mindset, and do some far-sighted SRE work.

You’ll combine hands-on work with technical leadership to:

• Influence without authority- understand our systems, advocate for reliability improvements, and build relationships with other teams and tech leads to help them prioritise and deliver reliability changes.

• Lead the adoption of new practices and tools - whether through prototypes, RFCs, working groups, or direct implementation. We want you to develop our engineering culture to think about reliability before, during, and after incidents.

• Collaborate with stream-aligned teams to design and deliver system improvements that benefit multiple internal consumers, not just a single application.

The projects

Some example projects might be:

• Set up load, performance, and stress tests to understand how our bespoke modelling system can scale and identify non-linear behaviours to improve.

• Work with development teams to design and implement controls that prevent common failures - like request killers or circuit breakers, and modify our incident-response process.

• Unpick some coupling in the production database

The requirements

Essential:

• Experience designing, building, and scaling data-intensive systems and ideally with Kubernetes, PostgreSQL hosted in AWS RDS, and Snowflake.

• A track record of shaping incident processes, on-call practices, or sharing reliability ownership across multiple teams.

• Deep understanding of site reliability principles and applying them to databases, including observability and limiting the impact of long-running or resource-heavy queries.

• Experience with infrastructure automation, like setting up monitoring and alerting for pipelines

Bonus:

• Strong academic background in maths, physics, computer science, engineering, or a related field.

• Active in tech or open-source communities, with a passion for sharing knowledge and inspiring others.

• An open mind and the flexibility to approach challenges from different angles.

• Experience with observability platforms such as DataDog.

• Experience with managing infrastructure management using Terraform.

• Familiarity Python, SQL, Go.

The salary

We expect to pay from £100,000 - £140,000 for this role. But, we’re open-minded, so definitely include your salary goals with your application. We routinely benchmark salaries against market rates, and run quarterly performance and salary reviews.

The culture

At iwoca, we prioritise a culture of learning, growth, and support, and invest in the professional development of our team members. We value diversity in thought and skill, and encourage you to explore new areas of interest to help us improve our products and services.

The offices

We put a lot of effort into making iwoca a brilliant place to work:

• Offices in London, Leeds, and Frankfurt with plenty of drinks and snacks

• Events and clubs, like bingo, comedy nights, yoga classes, football, etc.

The benefits

• Flexible working.

• Medical insurance from Vitality, including discounted gym membership

• A private GP service (separate from Vitality) for you, your partner, and your dependents.

• 25 days’ holiday, an extra day off for your birthday, the option to buy or sell an additional five days of annual leave,and unlimited unpaid leave

• A one-month, fully paid sabbatical after four years.

• Instant access to emotional and mental health support.

• 3% Pension contributions and share options.

• Generous parental leave and a nursery tax benefit scheme to help you save money.

• Cycle-to-work scheme and electric car scheme.

• Two company retreats a year, we’ve been to France, Italy, Spain, and further afield.

And to make sure we all keep learning, we offer:

• A learning and development budget for everyone.

• Company-wide talks with internal and external speakers.

• Access to learning platforms like Treehouse.