Machine Learning à Grande-Bretagne

We are on a mission to stop fraud and improve customer authentication within contact centres. With over £1.3bn stolen by fraudsters in the UK each year, it’s a huge problem affecting millions of people. Too often the solution has been to put in place cumbersome authentication processes that frustrate genuine customers, cause inefficiencies for organisations , and fail to actually prevent fraud.

Smartnumbers is changing this by providing enterprises with cutting edge solutions that give them real-time insight into caller risk. We combine patented machine learning technology with our deep domain knowledge to provide an invisible security layer for organisations and their customers.

Our cloud‑based SaaS software serves many large, regulated businesses in the UK, processing hundreds of millions of transactions year at low latencies and high availability.

We’re seeking a Principal Software Engineer to lead our Platform Group within the engineering department. This group is comprised of two small engineering teams (8 people in total), one focused on developing our core call event processing & media streaming platform and the other looking after our core SIP telephony services handling critical phone calls for our customers.

This role combines strategic leadership and line management responsibilities with hands‑on development work, and will report directly to the Chief Technology Officer.

You’ll spend 50% of your time driving technical direction, overseeing delivery, and supporting the growth and performance of your team, with the remaining time being spent actively coding and contributing to the development of your AWS hosted applications.

We have a hybrid working policy, with a minimum of two days per week at our smart City of London offices and the remaining days being trusted to work from home.

• Work with the CTO to define and evolve the technical vision and architecture for your teams’ services.
• Lead technical design decisions with a strong emphasis on resilience, scalability, security, and performance in AWS.
• Promote engineering excellence and modern DevOps practices.

• Partner with Product Managers to refine, prioritise and estimate work, ensuring engineering efforts align strongly with business goals.
• Ensure work flows in a Kanban style, frequently deploying changes whilst triaging and accommodating any issues.
• Optimise ways of working with the team and report on delivery effectiveness.

• Lead, mentor, and support a team of software engineers.
• Conduct 1 : 1s, performance reviews, and career development conversations.
• Foster a culture of collaboration, ownership, and continuous improvement.
• Run recruitment of new team members in line with company hiring processes.
• Manage approvals for leave requests and expense claims.
• Garner strong working relationships and collaborative practices across other business teams, including Product Management, Operations, Compliance and Executive.

• Actively contribute to the codebase, building and maintaining services / features.
• Guide the team through complex technical challenges and code reviews.
• Comply with coding and design standards to ensure high quality solutions.
• Use and advocate for AI tooling to streamline software development and delivery processes.

• Previous experience as a hands‑on Staff or Principal Engineer , ideally within a SaaS technology business serving large enterprise customers.
• Strong capability in AWS and event driven microservices architecture.
• Deep knowledge of object‑oriented programming best practices.
• Familiarity with Golang and / or Rust are a bonus.
• Experience with infrastructure‑as‑code (e.g. CloudFormation, AWS CDK).
• Understanding of CI / CD pipelines and containerisation (e.g. Docker, ECS, Fargate).
• Excellent communication and stakeholder management skills.
• Ability to influence and collaborate effectively across teams and leadership.
• Passion for mentoring and growing engineering talent.
• Background in agile methodologies , particularly Kanban.

As well as a competitive salary of circa £100k per annum , we also offer a comprehensive benefits package, covering a variety of areas, both professional and personal. These benefits include :

• Family friendly benefits including paid parental leave policies.
• An extensive health insurance policy for you ( option to add family members ).
• A workplace pension with Hargreaves Lansdown.
• Life insurance of 4x your salary.
• A discretionary annual bonus of up to 10% of your salary.
• 25 days of annual leave (plus bank holidays), your birthday off, and an opportunity to buy up to 5 days annual leave per year.
• A holistic wellbeing support plan encompassing a variety of offerings to assist you. We provide you with a monthly £50 allowance to fund activities to best support your wellbeing as well as workshops and training to provide tools and guidance. Additionally, there is a wide-ranging employee assistance programme available to advise on personal, family or financial matters.
• We have a hybrid working policy, with a minimum of two days per week at our smart City of London offices and the remaining days being trusted to work from home.

• Screening interview with the hiring manager
• Take home coding assessment
• Technical and competency-based interview with CTO & Senior Engineers
• Culture & values interview s with HR and Bar - r aiser

We help companies in the fight against fraud. Our solutions help protect organisations from downstream fraud by ensuring the contact centre stays secure. Through our consortium of customers and partners, we enable organisations to work together to fight fraud by sharing intelligence and best practice.

As a software company with a telecommunications pedigree, we create market‑leading security solutions for the contact centre. It’s why more than a thousand organisations trust us to help them fight fraud.

Our cloud‑based AI‑powered platform uses direct access to the carrier network, shared data on known fraudsters from our consortium and machine learning technology to protect your contact centre and your customers.

Find out more on how Smartnumbers helps organisations to prevent fraud and authenticate customers in one go here.

Smartnumbers is committed to promoting equal opportunities in employment. You will receive equal treatment regardless of age, disability, neurodiversity, gender, gender identity, gender reassignment, marital or civil partner status, pregnancy or maternity, race, colour, nationality, ethnic or national origin, religion or belief, sex and sexual orientation. We welcome all applications for this role.

We are committed to providing reasonable support / adjustments in our recruiting processes. If you need support, please reach out to the hiring contact.

Please see our privacy notice: https://smartnumbers.com/privacy-notice/