Senior Golang Engineer - AI Product & Platforms

We are Citi's Application, Platform and Engineering team, a start-up with the exciting mission of shaping the direction of travel for the entire bank under the Chief Technology Office, by defining the tech and engineering strategy for the bank. We are a team of talented engineers, product managers and tech SMEs, taking ambiguous concepts and making them real by engineering cutting edge products at planetary scale! We are solely focused on the most modern technology and engineering disciplines such as generative AI, cloud, security, modern app stacks (with Golang, Gatekeeper), open source and the latest and greatest in the Kubernetes ecosystem.

Generative AI is a growing space, as a result, we ask that you share with us any specific AI engineering projects utilising LLMs that you're proud of in your application. Ideally these projects should show off complex and clever architectures or a systematic evaluation of an LLM's behaviour.

You might be a good fit if you:

• Golang expertise essential.
• Bring your deep-dive Golang engineering expertise from building high-performance, large-scale production systems.
• Thrive in a results-driven environment, where flexibility fuels impact.
• Be a game-changer, ready to step beyond your designated role.
• Love the synergy of pair programming? So do we!
• Seize the opportunity to engineer robust, scalable platforms that power AI applications at enterprise scale.
• A relentless passion to learn more about distributed systems, cloud-native architectures, and bringing your knowledge to shape Citi's engineering future.

What you'll do within the Tech Strategy team:

• Build AI-powered products from 0-1 – Engineer production-grade, business-facing AI platforms with clean, performant, and maintainable Go code from day one.
• Design and build high-performance backend services – Architect and implement low-latency, high-throughput microservices in Go that operate reliably at planetary scale.
• Design and build developer tools and frameworks – Create reusable libraries, SDKs, and internal tooling in Go that accelerate development across fast-paced engineering teams.
• Tackle complex distributed systems challenges – Design solutions for concurrency, fault tolerance, data consistency, and service orchestration across large-scale distributed environments.
• Champion engineering excellence – Drive best practices in code quality, testing strategies, CI/CD pipelines, and observability to maintain velocity without sacrificing reliability.
• Mentor and elevate the team – Guide other engineers on Go idioms, system design patterns, performance optimisation, and building software that scales.

Experience That Will Help You Succeed In This Role:

• Production system builder – proven track record of architecting and building large-scale, high-availability production applications and business-facing platforms from the ground up using Go.
• Advanced Go expertise – deep proficiency in Go's concurrency model (goroutines, channels, select), memory management, profiling, and performance tuning for latency-sensitive systems.
• Microservices and API design – extensive experience designing, building, and maintaining RESTful and gRPC APIs with a focus on clean contracts, versioning, and backward compatibility in high-traffic production systems.
• HashiCorp Vault and secrets management – experience integrating with Vault for dynamic credentials, secrets engines, and enterprise-scale secrets management within Go services.
• Enterprise authentication & authorization – designing and implementing OAuth, JWT, RBAC, and complex identity systems with fine-grained access controls in business-critical applications.
• Cloud-native and Kubernetes expertise – building, deploying, and operating containerised Go applications in Kubernetes, leveraging service meshes, Helm charts, and cloud-native patterns at enterprise scale.
• AI/ML platform engineering – experience building backend infrastructure and APIs that serve AI/ML models, manage inference pipelines, and support LLM-powered applications at scale.
• Observability and reliability engineering – implementing comprehensive logging, metrics, distributed tracing, and alerting to ensure system health and rapid incident resolution.
• Database and data layer proficiency – strong experience with both SQL (PostgreSQL, MySQL) and NoSQL (Redis, MongoDB, DynamoDB) databases, including schema design, query optimisation, and caching strategies.
• Testing and CI/CD mastery – building robust test suites (unit, integration, end-to-end) and designing CI/CD pipelines that enable rapid, confident deployments to production.

What We Believe In:

• We do not have boundaries between backend engineering and product development, and we expect all our technical staff to contribute to both as needed.
• We take a product-focused approach to engineering and care about building solutions that are robust, scalable, and easy for developers to use.
• We enjoy working in a fast-paced team tackling cutting-edge engineering problems by constantly testing and learning.
• We enjoy pair programming for our platform services; we are lean in our approach and remove bureaucracy where we see it.
• We believe in delivering working software fast, iterating and pivoting as we go, rather than defining the perfect architecture upfront.

What we’ll provide you:

This is a unique role that will put you in the position to be part of a new venture and actively drive change. Every day there will be new challenges that will help you develop new skills that can drive your career. By joining Citi London, you will not only be part of a business casual workplace with a hybrid working model (up to 2 days working at home per week), but also receive a competitive base salary (which is annually reviewed), and enjoy a whole host of additional benefits such as:

• 27 days annual leave (plus bank holidays)
• A discretional annual performance related bonus
• Private Medical Care & Life Insurance
• Employee Assistance Program
• Pension Plan
• Paid Parental Leave
• Special discounts for employees, family, and friends

Visit our Global Benefits page to learn more.