Senior Software Engineer, Tech Lead - Citi in Belfast

Energy Jobline ZR; Belfast; Hybrid; GBP 80,000 - 100,000; Full time

Job summary

A leading global energy job board is seeking a Backend Engineer to shape the Developer Experience platform at their Belfast office. In this role, you will develop and maintain server-side code and infrastructure, ensuring that robust systems support thousands of engineers. Candidates must have strong skills in Kotlin, RESTful APIs, and containerization technologies, with a range of benefits including competitive salary and annual leave.

Benefits

27 days annual leave

Private Medical Care

Life Insurance

Pension Plan

Paid Parental Leave

Employee discounts

Learning and development resources

Qualifications

• Strong server-side engineering skills.
• Proficiency with relational and/or NoSQL databases.
• Experience with message queuing systems.
• Deep understanding of containerization and orchestration.
• Comfortable collaborating with product and design teams.

Responsibilities

• Build and maintain backend infrastructure and data pipelines.
• Integrate with upstream APIs to enhance system functionality.
• Design system architecture for near real-time data processing.
• Own server-side code and infrastructure.
• Solve complex engineering problems and gain consensus.

Skills

Kotlin

RESTful APIs

Asynchronous programming

PostgreSQL

MongoDB

Apache Kafka

Docker

Kubernetes

CI/CD tools

Tools

Spring Boot

Helm

Tekton

Harness

Job description

Energy Jobline is the largest and fastest growing global Energy Job Board and Energy Hub. We have an audience reach of over 7 million energy professionals, 400,000+ monthly advertised global energy and engineering jobs, and work with the leading energy companies worldwide.

We focus on the Oil & Gas, Renewables, Engineering, Power, and Nuclear markets as well as emerging technologies in EV, Battery, and Fusion. We are committed to ensuring that we offer the most exciting career opportunities from around the world for our jobseekers.

What you will do

Discover your future at Citi <Taken as part of role description> This role is to help build our next-Developer Experience (DevEx) platform at Citi using Kotlin. You'll be joining a small, high-impact team, shaping the daily lives of our 50,000 engineers globally by building the platform where engineers can see all parts of the software development life cycle, such as code reviews, JIRAs and deployments, all tied together into a workflow in near real-time. This is an exciting technical challenge for an ambitious candidate.

Where you'll work

You'll sit within Development Enablement, part of Citi's CTO organisation. A group focused on innovation, developer platforms and internal tools used across the bank, where we experiment and ship fast, like a startup inside a global bank. Our mission is to save our engineers tens of minutes per day, equating to £10,000,000s of savings at Citi's scale.

What you will do in your first year

By day 45

• Have worked with an external team to connect with an upstream system and shipped to production
• You'll have a fully documented OpenAPI contract agreed between client and server
• Created a performant API endpoint, with the time to first byte within 200ms

By 3 months - Create system architecture and establish key relationships

• Established some working relationships with engineering teams across Citi.
• Begun designing a systems architecture that takes into consideration our future near real-time requirements and the ability to link that data together into a workflow, such as being able to connect a JIRA ticket to a deployment in production
• Aligned the team on architectural principles, ways of working and system requirements. For example: you might choose dependency inversion for the code structure; opting for Availability and Partition tolerance over Consistency data; we also may decide that we want data to appear on the UI less than 1 second after it was received.

By 6 months - Architecture patterns established, integrated with several services

• You will have integrated with several upstream APIs - for example, a service that consolidates CI/CD status across multiple pipelines, or an aggregation service for production error metrics.
• Using your architectural principles and requirements, you'll have solved hard engineering problems, making the pros and cons visible and gaining consensus from the team.
• You will have bought additional technologies online (e.g., Kafka, Postgres, etc.) as needed to realize the architectural vision, meeting the requirements agreed upon by month 3.
• You will have received majority positive feedback from your colleagues on your technical leadership.

By 12 months - Own and run the backend infrastructure

• You'll own the server-side code and infrastructure data pipelines that support complete workflows, such as tracing a JIRA ticket's progression through build, test, and deployment into production.
• You will have taken full technical ownership of the backend platform with the team's approval and had a meaningful impact on the speed and scalability of the platform.
• The application will be capable of supporting 10,000 - 20,000 users per day in near real-time.

What you will bring

• Strong server-side engineering skills: Kotlin, building and consuming RESTful APIs, asynchronous programming.
• Proficiency with relational and/or NoSQL databases: PostgreSQL, MongoDB.
• Experience with message queuing systems: Apache Kafka.
• Deep understanding of containerization (Docker) and orchestration (Kubernetes).
• Familiarity with CI/CD tools like Tekton and deployment automation platforms like Harness.
• Comfortable collaborating with product, design, and UI engineers, and other stakeholders to understand requirements and deliver robust backend solutions.

Tools and technologies you might use

• Kotlin /Java, Spring Boot, PostgreSQL, MongoDB, Apache Kafka, Docker, Kubernetes, Helm, Tekton, Harness
• Mac or PC - it's up to you
• Access to time-saving AI tools such as GitHub Copilot

Why you'll love working here

• You'll shape the daily experience of tens of thousands of engineers at one of the largest engineering organizations in the world by building the resilient systems they rely on.
• You'll work in a small autonomous team, with impact across our global organization.
• You'll get to use your strong backend engineering skills on hard problems to build and shape a greenfield platform.

What we'll provide you

By joining Citi Belfast, 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 discretionary annual performance related bonus
• Private Medical Care & Life Insurance
• Employee Assistance Program
• Pension Plan
• Paid Parental Leave
• Special discounts for employees, family, and friends
• Access to an array of learning and development resources

Visit our About Us | Culture, Values & Benefits page to learn more. Alongside these benefits Citi is committed to ensuring our workplace is where everyone feels comfortable coming to work as their whole self, every day. We want the best talent around the world to be energized to join us, motivated to stay and empowered to thrive.

If you are interested in applying for this job please press the Apply Button and follow the application process. Energy Jobline wishes you the very best of luck in your next career move.