Back End Engineer

Keystone AI's mission is bold – to properly and permanently rid the world's banks of legacy technology. To achieve this, we have developed the foundations of modern banking through core and payments technology which run natively in the cloud. What we are attempting is hard and means we need great people working together to build great technology.
We have grown rapidly in the past few years – growing our team to more than 550 individuals across offices in London, New York, Singapore, Sydney and our newly established Engineering Hub in Lisbon. We have raised more than £500m in funding and our investors include Molten Ventures, Eurazeo, Intesa Sanpaolo, Temasek, Nyca Partners, JPMorgan Chase Strategic Investments, Standard Chartered Ventures, and more.
We have created a culture that enables our team to produce the best work in the industry while ensuring we have fun along the way. We're regularly cited as having a fantastic workplace culture and have been recognised by Sifted magazine as having one of the highest Glassdoor ratings for a UK fintech company and the industry's most generous employee share package. Named one of the world's most innovative fintechs by Global Finance Magazine, we were also recognised by the Financial Times as one of Europe's fastest-growing companies for two consecutive years—and a UK Best Employer for 2026.
Back End Engineering is a key role within Keystone AI as Back End Engineers lead the development of Keystone AI’s Vault product. We pride ourselves in excellence in this role, adopting the best practices in continuous deployment monorepo style development.
While development at Keystone AI is fast paced, you will be expected to develop code to a high standard and production ready state.
Duties
– Design, implement and develop scalable, performant microservices using best practices.
– Write automated unit tests, integrate tests, etc.
– Interfacing with other engineering teams to ensure that features are added in a structured and coherent way.
– Managing and debugging your deployments from testing environments all the way to production.
– Translating customer requirements into trackable tickets.
Requirements
Essential
– Experience with either Python or Golang.
– Experience in developing automated tests as an integral part of the development cycle.
– Interest in working on client-facing projects, conducting scoping and defining deliverables.
Desirable
– Knowledge of banking / finance.
– Experience with AWS or other cloud providers.
– Familiar with databases (SQL or noSQL).
– Experience with client/server software architectures & networking, or microservice architectures.
– Experience using orchestration tools such as Kubernetes or Mesos.
Benefits
– Highly competitive salary
– Pension plan (match up to 5%)
– Life insurance - three times annual salary
– Competitive maternity (six months fully paid) and paternity leave (four weeks fully paid)
– Shared parental leave (matched to our maternity leave for the same point in time)
– 25 days holiday and bank holidays
– Flexible working hours
– Cycle-to-work scheme
– Electric car scheme
– Season ticket loan
– Access to outstanding learning materials and courses
– Sports and hobby clubs, subsidised by Keystone AI
– All the latest tech you need
– Start the day properly with fresh fruit and cereals
– Huge range of healthy (and not-so-healthy) snacks, smoothies and drinks
– A talented and experienced team as your colleagues
– An environment where we encourage learning and progress
– Two charity days a year
– Weekly food pop-up
We actively hire candidates who demonstrate technical excellence in their field and welcome people of all ages and backgrounds, providing everyone with equal access to professional development. You are encouraged to apply even if your experience doesn't accurately match the job description. We also encourage applications from those with different abilities, including candidates with ADHD, autism, dyslexia or dyspraxia.