Senior Platform Engineer: Finance Tech & Modernisation

twentyAI; Greater London; On-site; GBP 90,000 - 130,000; Full time

Job summary

twentyAI is seeking an experienced software engineer to drive the modernization of core technology platforms and digital services in the UK. You will influence architecture across frontend, backend, data and infrastructure while collaborating with business teams and external vendors.

The role demands hands-on backend and full-stack expertise, strong Java, and a track record in delivering secure, scalable applications in a regulated financial context.

Qualifications

• Proven track record delivering production-grade software in a senior role.
• Strong Java backend development and API design experience.
• Full-stack knowledge across applications, data and infrastructure.
• Experience with service-based architectures and web applications.
• Proficient in automated testing, CI/CD and production support.
• Hands-on with Docker, Kubernetes and IaC tooling.
• Strong Linux administration and scripting skills.
• Understanding of observability and reliable service design.
• Experience in financial services or regulated environments.
• Excellent problem-solving and stakeholder communication, including executives.
• Experience with .NET and Python.
• Experience modernising legacy apps and platforms.
• Experience leading agile, cross-functional teams.
• Knowledge of Terraform and Helm and monitoring tools.

Responsibilities

• Design, build and improve secure, reliable and maintainable applications.
• Develop backend services and APIs using modern engineering practices.
• Translate business requirements into practical technology solutions.
• Contribute to solution design, implementation, deployment, testing and production support.
• Use automated testing, peer review, continuous delivery and clear documentation to maintain quality.
• Improve monitoring, logging, diagnostics and service reliability.
• Support team leadership, mentor colleagues and deputise for the technology lead when required.

Skills

Senior engineering

Java backend

Full-stack

API design

System integration

Web apps

Automated testing

Version control

CI/CD

Release management

Production support

Docker

Kubernetes

Infra as code

Linux admin

Scripting

Observability

Monitoring

FinServ experience

Leadership

Stakeholder comms

.NET and Python

Modernising legacy apps

Terraform

Helm

Prometheus

Grafana

Splunk

Agile leadership

Cross-functional teams

Education

A relevant degree or equivalent practical experience

Tools

Docker

Kubernetes

Terraform

Helm

Prometheus

Grafana

Splunk

Job description

twentyAI is seeking an experienced software engineer to drive the modernization of core technology platforms and digital services in the UK. You will influence architecture across frontend, backend, data and infrastructure while collaborating with business teams and external vendors.

The role demands hands-on backend and full-stack expertise, strong Java, and a track record in delivering secure, scalable applications in a regulated financial context.