StackOne
About StackOne: StackOne is the AI Integration Gateway for SaaS products and AI Agents. Backed by GV and Workday Ventures ($24M raised), we help builders of SaaS platforms and AI Agents orchestrate hundreds of scalable, accurate, and enterprise-grade integrations. Our platform combines 25,000 pre-mapped actions on 200 connectors, an AI-powered integration development toolkit, plus security by design: a real-time architecture, managed authentication and permissions, and end-to-end observability. Join us on our fast trajectory to build the future of agentic integrations. Why this role exists StackOne's product experience is our brand. As our first dedicated UX Engineer you will be the in house authority on taste, polish, and performance. You will own the component library, shape our micro frontend architecture, and ensure that every pixel, motion, and millisecond of latency makes customers feel like they're using the best engineered platform on the market. What you'll do 80 % Front-end craft & design systems 20 % API aware performance engineering Collaborate with our Designer to define & steward our design system - set the visual language, build reusable primitives, and maintain libraries that power every StackOne user interface. Ship pixel perfect UIs - React (primarily) plus; own theming, performance, and thoughtful motion. Make performance a feature - instrument Core Web Vitals, budget bundle sizes, optimise hydration patterns, and chase performance where it matters. Provide and maintain internal tooling as well as AI rules to allow every technical team to contribute to the front end while aligning with the best practices you will help set. Prototype & validate - turn product ideas into interactive proofs of concept that help PMs and designers converge on the right solution fast. Champion taste & detail - host design quality critiques, stamp out visual debt, and be the go to voice when "good enough" isn't. What you'll bring Must haves 4+ yrs professional front end engineering with a portfolio that focus on the details. React & TypeScript at production scale; comfortable with hooks, suspense, and server components. Deep CSS fluency (Tailwind or equivalent) and experience of modern browser APIs. Proven track record building or migrating component libraries/design systems. Strong performance tuning instincts: Lighthouse, Core Web Vitals, bundle analysis, code splitting. Familiarity with monorepo tooling (NX or Turborepo) and micro frontend patterns. Ability to dive into back end code (Node, React router, sveltekit) to remove perf bottlenecks, instrument metrics, or adjust API shape. Nice to haves Svelte, Web Components, or other framework experimentation. Experience with auth flows (OAuth2, OpenID Connect) and secure front end patterns. Web Motion & animation chops Prior work on B2B developer tools or dashboards at seed to Series B stage. Why Join Us? Meaningful share options (EMI) - share in the company's success as we grow 25 days holiday + 1 additional day per year of tenure Private health insurance - including dental & optical £15/day lunch budget when working from our London office, up to £120/month £1,000 for your home office set up + £500/year top up Annual team offsite to sunny spots (last ones were in Spain and Portugal ️) Join one of Europe's fastest growing startups Work with a veteran team of ex employees of Google, Microsoft, Oracle, Coinbase, JP Morgan and more Health, fitness and gift card discounts Cycle2Work and Electric Cars scheme Hybrid work set up - typically 2 days in the office Ready to help us change the game for SaaS integrations? Get in touch and let's chat! We believe diversity drives innovation. We encourage individuals from all backgrounds to apply. As an equal opportunity employer, we celebrate diversity and are committed to creating an inclusive environment for all employees.
About StackOne: StackOne is the AI Integration Gateway for SaaS products and AI Agents. Backed by GV and Workday Ventures ($24M raised), we help builders of SaaS platforms and AI Agents orchestrate hundreds of scalable, accurate, and enterprise-grade integrations. Our platform combines 25,000 pre-mapped actions on 200 connectors, an AI-powered integration development toolkit, plus security by design: a real-time architecture, managed authentication and permissions, and end-to-end observability. Join us on our fast trajectory to build the future of agentic integrations. Why this role exists StackOne's product experience is our brand. As our first dedicated UX Engineer you will be the in house authority on taste, polish, and performance. You will own the component library, shape our micro frontend architecture, and ensure that every pixel, motion, and millisecond of latency makes customers feel like they're using the best engineered platform on the market. What you'll do 80 % Front-end craft & design systems 20 % API aware performance engineering Collaborate with our Designer to define & steward our design system - set the visual language, build reusable primitives, and maintain libraries that power every StackOne user interface. Ship pixel perfect UIs - React (primarily) plus; own theming, performance, and thoughtful motion. Make performance a feature - instrument Core Web Vitals, budget bundle sizes, optimise hydration patterns, and chase performance where it matters. Provide and maintain internal tooling as well as AI rules to allow every technical team to contribute to the front end while aligning with the best practices you will help set. Prototype & validate - turn product ideas into interactive proofs of concept that help PMs and designers converge on the right solution fast. Champion taste & detail - host design quality critiques, stamp out visual debt, and be the go to voice when "good enough" isn't. What you'll bring Must haves 4+ yrs professional front end engineering with a portfolio that focus on the details. React & TypeScript at production scale; comfortable with hooks, suspense, and server components. Deep CSS fluency (Tailwind or equivalent) and experience of modern browser APIs. Proven track record building or migrating component libraries/design systems. Strong performance tuning instincts: Lighthouse, Core Web Vitals, bundle analysis, code splitting. Familiarity with monorepo tooling (NX or Turborepo) and micro frontend patterns. Ability to dive into back end code (Node, React router, sveltekit) to remove perf bottlenecks, instrument metrics, or adjust API shape. Nice to haves Svelte, Web Components, or other framework experimentation. Experience with auth flows (OAuth2, OpenID Connect) and secure front end patterns. Web Motion & animation chops Prior work on B2B developer tools or dashboards at seed to Series B stage. Why Join Us? Meaningful share options (EMI) - share in the company's success as we grow 25 days holiday + 1 additional day per year of tenure Private health insurance - including dental & optical £15/day lunch budget when working from our London office, up to £120/month £1,000 for your home office set up + £500/year top up Annual team offsite to sunny spots (last ones were in Spain and Portugal ️) Join one of Europe's fastest growing startups Work with a veteran team of ex employees of Google, Microsoft, Oracle, Coinbase, JP Morgan and more Health, fitness and gift card discounts Cycle2Work and Electric Cars scheme Hybrid work set up - typically 2 days in the office Ready to help us change the game for SaaS integrations? Get in touch and let's chat! We believe diversity drives innovation. We encourage individuals from all backgrounds to apply. As an equal opportunity employer, we celebrate diversity and are committed to creating an inclusive environment for all employees.
Citigroup Inc.
Citi is a world-leading global bank. We have approximately 200 million customer accounts and a presence in more than 160 countries and jurisdictions worldwide. We provide consumers, corporations, governments, and institutions with a broad range of financial products and services, including consumer banking and credit, corporate and investment banking, securities brokerage, transaction services, and wealth management. We enable clients to achieve their strategic financial objectives by providing them with cutting edge ideas, best in class products and solutions, and unparalleled access to capital and liquidity. About Us Join the Technology Application Strategy team, where we empower Citi's global developer community to build better, faster, and with greater satisfaction. We are a dynamic and globally distributed team of passionate technologists across London, Belfast, and the US, dedicated to designing, building, and deploying cutting edge productivity and tooling solutions. Our mission is to revolutionise the developer experience at Citi, providing innovative tools and platforms that streamline workflows, enhance efficiency, and foster a culture of continuous improvement. If you thrive on solving complex problems and aspire to make a significant impact on how thousands of developers operate worldwide, you'll find your challenge here. Role Overview / What will you do? You will play a key role in developing tooling for the Citi developer community using a range of technologies including Java and SpringBoot microservices on Linux on OpenShift. You'll build APIs to integrate with other systems across the bank using industry best practices. You will engage across the entire Software Development Lifecycle (SDLC), from initial design and architecture to development, testing, deployment, and ongoing support, ensuring the delivery of high quality, impactful solutions. Act as a trusted consultant and partner to developers worldwide within Citi. You will provide expert guidance, facilitating their onboarding and maximizing their utilization of the innovative tools and platforms you help create. You will serve as a subject matter expert for both senior stakeholders and team members. You will role model engineering excellence and play your part in actively fostering a culture of continuous learning and openly sharing your knowledge and experience. Key Skills and Experience You will be a highly motivated self starter who is comfortable taking on new challenges with an open and inquisitive mind and a readiness to learn. You will be a competent Java developer who drives with tests and understands the importance of writing clean, testable code. You will have a strong understanding of core Java and have experience building apps using SpringBoot. You will have experience working with build tools such as Gradle. You will be comfortable working with Linux and be familiar with standard developer tooling, such as Git, BitBucket/GitHub, Jira, Confluence, etc. You will have a knowledge of build pipelines, CI/CD and the pathway to production. Desirable Skills Working knowledge of app containerisation and deploying applications on cloud platforms (e.g. OpenShift, AWS, GCP) with Docker or Podman. Experience with relational databases such as Oracle. 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 Job Family Group Technology Job Family Applications Development Time Type Full time EEO Statement Citi is an equal opportunity employer, and qualified candidates will receive consideration without regard to their race, color, religion, sex, sexual orientation, gender identity, national origin, disability, status as a protected veteran, or any other characteristic protected by law. If you are a person with a disability and need a reasonable accommodation to use our search tools and/or apply for a career opportunity review Accessibility at Citi. View Citi's EEO Policy Statement and the Know Your Rights poster.
Citi is a world-leading global bank. We have approximately 200 million customer accounts and a presence in more than 160 countries and jurisdictions worldwide. We provide consumers, corporations, governments, and institutions with a broad range of financial products and services, including consumer banking and credit, corporate and investment banking, securities brokerage, transaction services, and wealth management. We enable clients to achieve their strategic financial objectives by providing them with cutting edge ideas, best in class products and solutions, and unparalleled access to capital and liquidity. About Us Join the Technology Application Strategy team, where we empower Citi's global developer community to build better, faster, and with greater satisfaction. We are a dynamic and globally distributed team of passionate technologists across London, Belfast, and the US, dedicated to designing, building, and deploying cutting edge productivity and tooling solutions. Our mission is to revolutionise the developer experience at Citi, providing innovative tools and platforms that streamline workflows, enhance efficiency, and foster a culture of continuous improvement. If you thrive on solving complex problems and aspire to make a significant impact on how thousands of developers operate worldwide, you'll find your challenge here. Role Overview / What will you do? You will play a key role in developing tooling for the Citi developer community using a range of technologies including Java and SpringBoot microservices on Linux on OpenShift. You'll build APIs to integrate with other systems across the bank using industry best practices. You will engage across the entire Software Development Lifecycle (SDLC), from initial design and architecture to development, testing, deployment, and ongoing support, ensuring the delivery of high quality, impactful solutions. Act as a trusted consultant and partner to developers worldwide within Citi. You will provide expert guidance, facilitating their onboarding and maximizing their utilization of the innovative tools and platforms you help create. You will serve as a subject matter expert for both senior stakeholders and team members. You will role model engineering excellence and play your part in actively fostering a culture of continuous learning and openly sharing your knowledge and experience. Key Skills and Experience You will be a highly motivated self starter who is comfortable taking on new challenges with an open and inquisitive mind and a readiness to learn. You will be a competent Java developer who drives with tests and understands the importance of writing clean, testable code. You will have a strong understanding of core Java and have experience building apps using SpringBoot. You will have experience working with build tools such as Gradle. You will be comfortable working with Linux and be familiar with standard developer tooling, such as Git, BitBucket/GitHub, Jira, Confluence, etc. You will have a knowledge of build pipelines, CI/CD and the pathway to production. Desirable Skills Working knowledge of app containerisation and deploying applications on cloud platforms (e.g. OpenShift, AWS, GCP) with Docker or Podman. Experience with relational databases such as Oracle. 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 Job Family Group Technology Job Family Applications Development Time Type Full time EEO Statement Citi is an equal opportunity employer, and qualified candidates will receive consideration without regard to their race, color, religion, sex, sexual orientation, gender identity, national origin, disability, status as a protected veteran, or any other characteristic protected by law. If you are a person with a disability and need a reasonable accommodation to use our search tools and/or apply for a career opportunity review Accessibility at Citi. View Citi's EEO Policy Statement and the Know Your Rights poster.