Junior Software Engineer jobs in United Kingdom

London, UK

Postman is the world’s leading API platform, used by more than 40 million developers and 500,000 organizations, including 98% of the Fortune 500. Postman is helping developers and professionals across the globe build the API‑first world by simplifying each step of the API lifecycle and streamlining collaboration—enabling users to create better APIs, faster.

The company is headquartered in San Francisco and has offices in Boston, New York, and Bangalore – where Postman was founded. Postman is privately held, with funding from Battery Ventures, BOND, Coatue, CRV, Insight Partners, and Nexus Venture Partners. Learn more at postman.com or connect with Postman on X via @getpostman.

The Client Platform team is seeking a Senior Frontend Engineer to join our UI Platform charter and help us raise the quality bar across our frontend ecosystem. You'll establish engineering excellence through improved architecture, performance optimization, and maintainable code patterns that ensure our platform delivers exceptional experiences.

You'll work alongside other senior engineers to own different aspects of our UI Platform (design system, accessibility, internationalization, theming, etc.). This is a unique opportunity to have an immediate impact on the foundation that hundreds of Postman engineers and our 40+ million customers rely on daily.

The Client Platform team is a global engineering organization responsible for creating a "paved path" for all Postmanauts to develop and release web-based applications. Our platform is the foundation that 240+ engineers at Postman rely on daily to deliver new features and improvements to over 40 million customers.

• Design and implement scalable, maintainable front-end solutions, focused on the presentation layer
• Design system and component library
• Application shell & layout
• Global UI patterns
• Accessibility
• Theming/styling architecture
• Keyboard shortcuts
• Own technical initiatives end‑to‑end from design through delivery and maintenance
• Establish best practices and standards for SDK development
• Collaborate with cross‑functional teams to ensure SDK meets product requirements
• Mentor other engineers and contribute to technical decision-making
• Drive technical initiatives that enhance the SDK's performance, reliability, and developer experience
• Identify and proactively address technical debt and opportunities for improvement in our platform
• Participate in production support and incident resolution for SDK‑related issues

• 5-10 years of professional software engineering experience
• 2+ years in a similar senior role
• Experience with design systems, accessibility compliance (WCAG2.1AA), or internationalization at scale

• Communicates clearly and listens effectively. You seek new perspectives and build trust with your colleagues.
• Loves the challenge of constraints and excels at finding creative solutions.
• Takes ownership of problems, not solutions, and celebrates success as a team.
• Has demonstrated expertise in code quality, performance optimization, and engineering excellence.
• Has experience designing and implementing maintainable, scalable frontend architectures for complex applications, including component libraries and SDKs that can be effectively reused across multiple systems.
• Has a proven track record of raising the quality bar in previous roles through both technical solutions and positive cultural impact.

• Experience with cross‑platform applications (Electron or similar) and understanding the unique challenges of desktop/web hybrid environments.
• Creating widely‑adopted (open source) libraries/SDKs with 1000+ active developers.

In addition to Postman's pay‑on‑performance philosophy, and a flexible schedule working with a fun, collaborative team, Postman offers a comprehensive set of benefits, including full medical coverage, flexible PTO, wellness reimbursement, and a monthly lunch stipend. Along with that, our wellness programs will help you stay in the best of your physical and mental health. Our frequent and fascinating team‑building events will keep you connected, while our donation‑matching program can support the causes you care about. We’re building a long‑term company with an inclusive culture where everyone can be the best version of themselves.

At Postman, we embrace a hybrid work model. For all roles based out of San Francisco Bay Area, Boston, Bangalore, Hyderabad, London, and New York, employees are expected to come into the office 3‑days a week. We were thoughtful in our approach which is based on balancing flexibility and collaboration and grounded in feedback from our workforce, leadership team, and peers. The benefits of our hybrid office model will be shared knowledge, brainstorming sessions, communication, and building trust in‑person that cannot be replicated via zoom.

At Postman, we create with the same curiosity that we see in our users. We value transparency and honest communication about not only successes, but also failures. In our work, we focus on specific goals that add up to a larger vision. Our inclusive work culture ensures that everyone is valued equally as important pieces of our final product. We are dedicated to delivering the best products we can.

Postman is an Equal Employment Opportunity and Qualitative Action Employer. Qualified applicants will receive consideration for employment without regard to race, color, religion, sex, sexual orientation, gender perception or identity, national origin, age, marital status, protected veteran status, or disability status. Headhunters and recruitment agencies may not submit resumes/CVs through this website or directly to managers. Postman does not accept unsolicited headhunter and agency resumes. Postman will not pay fees to any third‑party agency or company that does not have a signed agreement with Postman.