Staff Application Engineer in London

The Onyx Research Data Tech organization represents a major investment by GSK R&D and Digital & Tech, designed to deliver a step-change in our ability to leverage data, knowledge, and prediction to find new medicines. We are a full-stack shop consisting of product and portfolio leadership, data engineering, infrastructure and DevOps, data / metadata / knowledge platforms, and AI/ML and analysis platforms, all geared toward:

• Building a next-generation data experience for GSK's scientists, engineers, and decision-makers, increasing productivity and reducing time spent on "data mechanics".
• Providing best-in-class AI/ML and data analysis environments to accelerate our predictive capabilities and attract top-tier talent.
• Aggressively engineering our data at scale to unlock the value of our combined data assets.
• Implementing scientific technology products that leverage the data and capabilities provisioned by Onyx.

As a Staff Application Engineer (Individual Contributor), you are a highly experienced technical leader who delivers high-impact engineering outcomes across multiple teams and products without formal people management responsibilities. You will take ambiguous, cross-functional problems from concept to scalable solutions; drive architecture and systems design that meet Onyx's standards for security, reliability, and performance; raise the quality bar for engineering excellence; and mentor engineers to level up their technical and operational capabilities. You will own the operation of the applications you build, lead the resolution of complex incidents, and champion best practices in observability, testing, and automation. Your work directly increases the value we deliver to GSK's scientific community.

In this role you will:

• Lead architecture and systems design for full-stack, data-driven, loosely coupled cloud applications; make pragmatic trade-offs that balance speed, quality, and long-term stability.
• Take poorly defined, high-ambiguity problems and drive them to a clear specification and execution plan; deliver solutions with cross-organizational impact and value.
• Own end-to-end delivery of large, strategic engineering initiatives, often crossing collective boundaries; ensure alignment to agreed target architectures and standards.
• Write high-quality, well-tested code and documentation; produce proposals, runbooks, and operational playbooks that enable clarity, maintenance, and scaling.
• Champion operational excellence: design for reliability and security, implement comprehensive observability (metrics, logs, traces), and ensure robust alerting and SLOs.
• Operate and support production systems: participate in on-call, lead incident resolution when needed, perform root-cause analysis, and drive durable follow-ups that reduce risk.
• Proactively refactor and simplify complex systems; repay technical debt with intent and measurable outcomes; improve performance, scalability, and cost efficiency.
• Develop APIs (REST/GraphQL/gRPC) and integration contracts that are resilient, secure, and well documented; advocate for consistent patterns across teams.
• Collaborate closely with product, design, data science, compliance/risk, and platform teams to align architectural decisions with user needs and organizational strategy.
• Mentor and sponsor engineers across teams (including senior engineers): raise coding standards, guide design choices, and help others navigate trade-offs and delivery.
• Elevate engineering practices across Onyx: standard-bearer for code reviews, test automation, CI/CD, accessibility, performance, and security-first design.
• Use data to inform decisions; introduce monitoring where needed to improve product and operational outcomes; communicate risk clearly to non-technical stakeholders.
• Stay current with relevant technologies (cloud-native services, data platforms, front-end frameworks); bring strategic insights that shape area-level technology direction.
• Contribute to cross-team initiatives that improve ways of working, incident management, support processes, and the overall quality bar for Onyx Application Engineering.

Qualifications & Skills:

We are looking for professionals with these required skills to achieve our goals:

• Bachelor's degree in Computer Science or related field, or equivalent experience.
• Significant experience delivering complex, production-grade, cloud applications at scale.
• Deep knowledge and practical use of at least one backend language and ecosystem (e.g., Python, Java, Scala, JavaScript/Node.js), including documentation, testing, observability, and operations.
• Proficiency in front-end technologies: JavaScript/TypeScript with React.js, Angular, or similar frameworks.
• Strong experience designing and building APIs (REST/GraphQL/gRPC); solid understanding of integration patterns and interoperability.
• Cloud experience developing and deploying in environments like Google Cloud (preferred), AWS, or Azure; hands-on with cloud-native services and infrastructure-as-code patterns.
• Experience with authentication and authorization mechanisms (e.g., OAuth2, OIDC); security-first mindset throughout the SDLC.
• Strong experience with modern SDLC and DevOps tooling: git/GitHub, CI/CD pipelines, automated testing, containerization/orchestration, metrics/monitoring (e.g., Prometheus, Grafana, OpenTelemetry).
• Demonstrated ability to lead architectural designs for complex systems, drive cross-team solutions, and deliver measurable improvements in reliability, performance, and scalability.
• Proven ability to debug and resolve complex production issues under pressure; leads incident resolution and drives durable prevention.
• Excellent communication skills (verbal and written); can articulate technical risk and decisions to technical and non-technical stakeholders; collaborates effectively across disciplines.
• Experience in agile software development and common environments such as Jira and Confluence.
• Track record of mentoring engineers and elevating team standards and ways of working.

Preferred Qualifications & Skills:

If you have the following characteristics, it would be a plus:

• Master's degree or higher in Computer Science or related field.
• Experience leading large, strategic, complex engineering projects across multiple teams or collectives.
• Knowledge of database modelling, relational and non-relational data concepts, and SQL; performance tuning and data lifecycle management at scale.
• Experience with data visualization frameworks (e.g., D3.js, Plotly, Matplotlib) and building scientific data experiences.
• Evidence of embedding operational excellence (runbooks, on-call discipline, SLOs, post-incident learning) across teams.
• Familiarity with regulated environments and collaboration with compliance/security functions.

Behaviours and Ways of Working:

• Standard-bearer for engineering discipline, code quality, testing, observability, and secure-by-design.
• Calm and structured during incidents or emergencies; leads others to clarity and resolution.
• Proactively mentors and sponsors engineers; seeks and gives timely, constructive feedback.
• Challenges teams to increase urgency on high-priority outcomes; raises visibility of work and impact.
• Stays up to date with technology trends and contributes to area-level strategy; proposes pragmatic changes aligned to business priorities.
• Uses data to guide decisions; introduces monitoring where gaps exist; improves operational and product metrics over time.

Closing Date for Applications: Tuesday 6th January 2026 (COB)

Please note: As we approach the holiday season, our recruitment team and hiring managers will have limited availability between now and early January. We encourage you to apply and will review all applications, however response times may be longer than usual, and interviews may be scheduled after the New Year. We appreciate your understanding and look forward to connecting soon!

Please take a copy of the Job Description, as this will not be available post closure of the advert.

When applying for this role, please use the 'cover letter' of the online application or your CV to describe how you meet the competencies for this role, as outlined in the job requirements above. The information that you have provided in your cover letter and CV will be used to assess your application.

During the course of your application, you will be requested to complete voluntary information which will be used in monitoring the effectiveness of our equality and diversity policies. Your information will be treated as confidential and will not be used in any part of the selection process. If you require a reasonable adjustment to the application / selection process to enable you to demonstrate your ability to perform the job requirements, please contact 0808 234 4391. This will help us to understand any modifications we may need to make to support you throughout our selection process.

GSK is a global biopharma company with a purpose to unite science, technology and talent to get ahead of disease together. We aim to positively impact the health of 2.5 billion people by the end of the decade, as a successful, growing company where people can thrive. We get ahead of disease by preventing and treating it with innovation in specialty medicines and vaccines. We focus on four therapeutic areas: respiratory, immunology and inflammation; oncology; HIV; and infectious diseases – to impact health at scale.

People and patients around the world count on the medicines and vaccines we make, so we're committed to creating an environment where our people can thrive and focus on what matters most. Our culture of being ambitious for patients, accountable for impact and doing the right thing is the foundation for how, together, we deliver for patients, shareholders and our people.

GSK is an Equal Opportunity Employer. This ensures that all qualified applicants will receive equal consideration for employment without regard to race, color, religion, sex (including pregnancy, gender identity, and sexual orientation), parental status, national origin, age, disability, genetic information (including family medical history), military service or any basis prohibited under federal, state or local law.

We believe in an agile working culture for all our roles. If flexibility is important to you, we encourage you to explore with our hiring team what the opportunities are.