897 Back End Developers jobs in London

About Medly AI

We're the fastest growing EdTech startup in London, on a mission to change education forever.

We're living through a once-in-a-generation moment where AI-native companies are redefining entire industries - Cursor for code, Midjourney for image gen, Harvey for law. Medly is building a generational company for education.

In just 4 months since launch, we’ve achieved retention rates that beat Duolingo and delivered personalized education to over 100,000 users. We’re looking for ambitious talent to join our team.

Backed by impact-focused VCs and supported by partners including UCL, Innovate UK, Microsoft, and Google, we're becoming the go-to AI education platform for all major exams worldwide.

The Role

We are looking for a passionate Back-End Engineer to join our growing team at Medly. This is a new role working closely with our hands-on Technical CEO other Full Stack Engineers to shape the backbone of our data infrastructure. You will play a pivotal role in high-impact projects such as migrating our systems to AWS, consolidating our databases, worked on our python based AI backend and building a unified environment optimized for cost, latency, and scalability. This is a high-impact opportunity for someone eager to take ownership, solve complex challenges, and help power the next generation of educational technology.

Role Responsibilities

• Build and optimize a unified, cost-efficient, low-latency data environment within AWS
• Work on our AI backend and help make it scale proof
• Help with migration to AWS
• Consolidate mobile and web databases into one optimized Postgres environment
• Develop processes for importing and editing data directly in the database
• Collaborate closely with the CEO and other Full Stack Engineers on high-impact projects

Technical Requirements

• 2–3 years of back-end engineering experience, ideally in a startup environment
• Strong knowledge of Python and Flask
• Proficiency with SQL and Postgres
• Experience with AWS services (migration experience is a plus)

Ideal Candidate

• Quality Focus: Obsessive attention to detail and commitment to shipping polished, bug-free experiences
• Collaborative Spirit: Ability to work closely with designers, product managers, and other developers
• Office Presence: Able to commute 4 out of 5 days a week to our office in Kings Cross, with Wednesday being work from home
• Educational Interest: Passion for education and learning, though specific EdTech experience isn't required
• Startup Mindset: Thrives in fast-paced environments with rapid iteration and high impact
• Innovation Drive: Excited by the opportunity to build cutting-edge educational technology

What We Offer

• Competitive salary
• Opportunity to make a real impact on educational outcomes for students worldwide
• Collaborative, diverse team united by a powerful mission
• Fast-paced environment with significant growth and development opportunities
• Regular team events and a culture focused on innovation and impact
• Work on products used by tens of thousands of students daily
• Shape the future of AI-powered education

Overview

GSK is a science-led global healthcare company with a special purpose: to help people do more, feel better, live longer. We are on an audacious journey to impact the health of 2.5 billion people over the next decade. Our R&D division is at the forefront of this mission, dedicated to the discovery and development of groundbreaking vaccines and medicines. We are transforming the landscape of medical research by integrating cutting-edge science and technology and harnessing the power of genetics and new data. By fostering a collaborative environment that unites the talents of our people, we are revolutionizing R&D to pre-empt and defeat diseases. Join us in our commitment to uniting science, technology, and talent to get ahead of disease together.

Role/Project Overview

At GSK we see a world in which advanced applications of Machine Learning and AI will allow us to develop novel therapies to existing diseases and to quickly respond to emerging or changing diseases with personalized drugs, driving better outcomes at reduced cost with fewer side effects. It is an ambitious vision that will require the development of products and solutions at the cutting edge of Machine Learning and AI, as well as extensive safety and robustness evaluations. We’re looking for a highly skilled full stack engineer to help us make this vision a reality.

Competitive candidates will have a track record of writing and shipping quality, well-documented and well-tested software in the AI/ML industry. We are looking for candidates with experience in the field of Responsible AI, preferably for generative AI or language applications. In addition to ML engineering and data science skills, ideal candidates will demonstrate a keen interest in ethical and safety aspects of using AI in drug discovery and the clinic.

The Responsible AI team is built on the principles of ownership, accountability, continuous development, and collaboration. This fixed-term position is a unique opportunity to contribute to the development and evaluation of generative AI for drug discovery in a fast-paced environment, with a focus on impact and in collaboration with a large team. Our leaders will be committed to your career and development from day one.

 Key Responsibilities

• Backend development of generative AI evaluations for a Python web application.
• Integration of AI/ML components with frontend, backend, data and compute infrastructure.
• Responsible for high quality software implementations according to best practices, including automated test suites and documentation.
• Participate in code reviews, continuously improving personal standards as well as the wider team and product.
• Liaise with other technical staff and data engineers in the team and across allied teams, to build an end-to-end pipeline consuming other data products.
• Deliver ML- and data-driven insights on GenAI datasets.

Minimum Qualifications

• A degree in a quantitative or engineering discipline (e.g., computer science, computational biology, bioinformatics, engineering, among others); OR equivalent work experience as a professional ML engineer or data scientist.
• Strong skills in Python, with experience in backend development and unit testing.
• Knowledge of generative AI, specifically Large Language Models.
• Knowledge of agile practices and able to perform in agile software development environments.
• Strong knowledge of modern software development tools / ways of working (e.g. git/GitHub, DevOps tools for deployment) – should be able to show practice of commit early and deploy often.

Preferred Qualifications

• Experience with safety and/or robustness evaluations of generative AI, e.g. defining guardrails, red teaming or persona-based evaluations.
• Knowledge of AI/ML approaches and deployment of AI/ML powered applications – especially using language models or NLP and agent-based approaches (e.g. LangGraph, PydanticAI, AutoGen),
• Knowledge of AI/ML evaluation and benchmarking approaches, experience with iterative improvement of AI/ML models and products.
• Research experience (e.g., Master’s project, internship at research organization).
• Cloud experience (e.g. Google Cloud and cloud run preferred) including core web application infrastructure.

Why GSK?

Uniting science, technology and talent to get ahead of disease together.

GSK is a global biopharma company with a special purpose – to unite science, technology and talent to get ahead of disease together – so we can positively impact the health of billions of people and deliver stronger, more sustainable shareholder returns – as an organisation where people can thrive. We prevent and treat disease with vaccines, specialty and general medicines. We focus on the science of the immune system and the use of new platform and data technologies, investing in four core therapeutic areas (infectious diseases, HIV, respiratory/ immunology and oncology).

Our success absolutely depends on our people. While getting ahead of disease together is about our ambition for patients and shareholders, it’s also about making GSK a place where people can thrive. We want GSK to be a place where people feel inspired, encouraged and challenged to be the best they can be. A place where they can be themselves – feeling welcome, valued, and included. Where they can keep growing and look after their wellbeing. So, if you share our ambition, join us at this exciting moment in our journey to get Ahead Together.

Inclusion at GSK

GSK is an Equal Opportunity/Affirmative  Action Employer. All qualified applicants will receive equal consideration for employment without regard to race, color, national origin, religion, sex, pregnancy, marital status, sexual orientation, gender identity/expression, age, disability, genetic information, military service, covered/protected veteran status or any other federal, state or local protected class.

If you need any adjustments in the recruitment process, please get in touch with our Recruitment team ( ) to further discuss this today.

Important notice to employment businesses/agencies

GSK does not accept referrals from employment businesses and/or employment agencies in respect of the vacancies posted on this site. All employment businesses/agencies are required to contact GSK's commercial and general procurement/human resources department to obtain prior written authorization before referring any candidates to GSK. The obtaining of prior written authorization is a condition precedent to any agreement (verbal or written) between the employment business/ agency and GSK. In the absence of such written authorization being obtained any actions undertaken by the employment business/agency shall be deemed to have been performed without the consent or contractual agreement of GSK. GSK shall therefore not be liable for any fees arising from such actions or any fees arising from any referrals by employment businesses/agencies in respect of the vacancies posted on this site.

Please note that if you are aUS Licensed Healthcare Professional or Healthcare Professional as defined by the laws of the state issuing your license, GSK may be required to capture and report expenses GSK incurs, on your behalf, in the event you are afforded an interview for employment. This capture of applicable transfers of value is necessary to ensure GSK’s compliance to all federal and state US Transparency requirements. For more information, please visit GSK’s Transparency Reporting For the Record site.

About Seapoint
Seapoint is building the financial home for European startups and scale-ups. We're an AI-powered business account that handles everything from payroll and expenses to invoice payments and reporting - all in one place.

Founded by Sean Mullaney (former European CIO at Stripe) and a team of alumni from Stripe, Wise, Wayflyer, Nubank and Tide, we've just raised $3M in pre-seed funding led by Frontline Ventures. After 9 months of building, we're now in private beta with dozens of VC-backed startups who are finally getting the bird's-eye view of their finances they've always needed.

The problem we're solving is real: European startups are stuck between neobanks (too small) and traditional corporate banking (too big). They're juggling 4-6 different financial products, running processes manually, and earning no interest on cash deposits. We're changing that with AI automation that handles the tedious financial work, so founders can focus on building their businesses instead of managing spreadsheets.

Read more about what we’re building here .

About the role
Build the financial infrastructure that powers the next generation of startups.

You'll architect core systems for multi-currency accounts, automated payments, and treasury management—technology that high-growth companies depend on to scale. Working with modern distributed systems, you'll tackle complex financial challenges while ensuring the reliability and security our users trust.

We're looking for engineers with varying backgrounds who are passionate about building something new. You'll work alongside ex-founders and veterans from Stripe, Wise, and Tide who understand what startups need to scale.

Languages and frameworks can be learnt, but if you’re curious we use a modern typescript and bun backed stack with postgreSQL and a bunch of AWS services. We are always curious about new ways of building software and embrace AI tools.

Note: Open to candidates authorised to work in Ireland/UK. Exceptional remote candidates across Europe considered.

Requirements

What matters: Systems thinking, attention to detail, and a drive to solve real problems for founders.

Essential Qualifications:

• Strong software engineering skill and a passion for startup life and helping founders
• 5+ years of professional software development experience
• Fluency in Typescript or a major programming language like Java, Ruby, Go, Python, etc

• Strong product instincts—showcase prior experience in designing and developing key customer features at scale
• Interest in leveraging AI for genuine financial solutions
• Fintech domain experience will be highly valued but not required

Benefits

• Competitive salary with meaningful equity in a fast-growing fintech startup
• Work directly with experienced founders and engineers from Stripe, Tide, Wise, Nubank, Wayflyer and other fintech unicorns
• Front-row seat to building category-defining financial infrastructure for Europe's startup ecosystem
• Flexible hybrid working from our Dublin base
• Learning and development opportunities in fintech and AI

Salary banding: £65,000 - £80,000 dependent on experience

Working pattern: Hybrid; 1-2 days per week in the office

Location: London

As a business which has AI at its core, we need to have a reliable, scalable and secure real-time ML platform to deliver our product to customers. The Engineering team makes this happen.

The team is UK-based, with a significant contingent in London, and is made up of pragmatic, curious and collaborative problem-solvers who are passionate about working with our Data Scientists to build state of the art AI products. Our Software Engineers bring together a diverse range of expertise and backgrounds; what unites us is a desire to learn, a mastery of our discipline and strong technical prowess.

Our engineers are responsible for all aspects of the software development lifecycle. You will get the opportunity to work across our entire stack building features which deliver AI capabilities to some of the biggest names in the insurance industry.

We are developing a modern real-time ML platform using technologies like FastAPI, PyTorch, Ray, k8s (helm + flux), Terraform, Postgres, Flink on AWS, React & Typescript. We operate a fully Python stack except for frontend and infrastructure code. We are very big fans of Infrastructure-as-Code and enjoy Agile practices. 

As a team, we're driven by a relentless focus on delivering real value to customers at speed. We embrace modern engineering practices such as automated testing, continuous monitoring, feature flags, and on-demand production-like environments to support frequent, reliable releases.

Our team is tackling several exciting challenges, including:

• Deploying all changes, including complex machine learning models, reliably to customers within 15 minutes
• Building a real-time, configuration-driven platform that seamlessly adapts to diverse customer needs
• Ensuring autoscaling and cost-efficient model serving in production, with robust support for ML monitoring and experimentation
• Centralised reporting/metrics for both the business and our customers
• Powering user experience of internal and external users through agentic workflows

We are looking for an engineer passionate about developer enablement and infrastructure as code, who is eager to expand their expertise by contributing to impactful product features. You'll play a key role in improving the lives of millions of insurance policyholders globally, working with a modern and powerful technology stack that includes:

• Python for application development
• Terraform for AWS infrastructure provisioning
• Kubernetes (with Helm and Flux) for managing services
• GitLab for CI/CD and version control
• AWS as our infrastructure platform
• PostgreSQL for application data and event sourcing architecture
• Apache Flink for real-time service interactions and state management

• Collaborate with Engineers, Product Managers, and the Engagement team to understand problem spaces, contribute to solution design, and support the development of our product.
• Take responsibility for maintaining and improving parts of our backend stack, following engineering best practices.
• Write robust and well-tested code, including unit, integration, and end-to-end automated tests for backend services that power customer-facing features.
• Participate in code reviews, share feedback with peers, and stay informed about emerging backend technologies and patterns.
• Contribute to platform-related work, using infrastructure-as-code tools (AWS, Terraform, Kubernetes) to help keep our systems reliable and scalable.
• Support the growth of the team by sharing knowledge and collaborating closely with engineers and data scientists.
• Help improve engineering workflows and contribute ideas for refining team processes and delivery methods.
• Play a role in feature rollouts by using feature flags, monitoring metrics, and responding to logs and alerts.
• Embody and promote the Engineering and Sprout company values in your day-to-day work.

• Technical proficiency
• Solid proficiency in software architecture using Python and FastAPI.
• Experience working in fully cloud-hosted environments (e.g. AWS).
• Solid RDBMS experience, preferably with PostgreSQL
• Experience building RESTful APIs (e.g. FastAPI) and real-time data processing pipelines
• Bonus points for experience with Kubernetes, Apache Flink, Flux or Infrastructure-as-Code frameworks (e.g. Terraform).
• Experience of maintaining your own code in a production environment.
• A good foundational understanding of modern software development lifecycles, including code quality, pull requests, code reviews, CI/CD, QA, and production releases in an agile, fast-paced environment
• Strong problem-solving skills with the ability to think critically and creatively
• Collaborative by nature, with excellent communication and teamwork abilities
• Self-motivated, with a strong sense of ownership and accountability

Salary banding: £65,000 - £80,000 dependent on experience

Working pattern: Hybrid; 1-2 days per week in the office

Location: London

As a business which has AI at its core, we need to have a reliable, scalable and secure real-time ML platform to deliver our product to customers. The Engineering team makes this happen.

The team is UK-based, with a significant contingent in London, and is made up of pragmatic, curious and collaborative problem-solvers who are passionate about working with our Data Scientists to build state of the art AI products. Our Software Engineers bring together a diverse range of expertise and backgrounds; what unites us is a desire to learn, a mastery of our discipline and strong technical prowess.

Our engineers are responsible for all aspects of the software development lifecycle. You will get the opportunity to work across our entire stack building features which deliver AI capabilities to some of the biggest names in the insurance industry.

We are developing a modern real-time ML platform using technologies like FastAPI, PyTorch, Ray, k8s (helm + flux), Terraform, Postgres, Flink on AWS, React & Typescript. We operate a fully Python stack except for frontend and infrastructure code. We are very big fans of Infrastructure-as-Code and enjoy Agile practices. 

As a team, we're driven by a relentless focus on delivering real value to customers at speed. We embrace modern engineering practices such as automated testing, continuous monitoring, feature flags, and on-demand production-like environments to support frequent, reliable releases.

Our team is tackling several exciting challenges, including:

• Deploying all changes, including complex machine learning models, reliably to customers within 15 minutes
• Building a real-time, configuration-driven platform that seamlessly adapts to diverse customer needs
• Ensuring autoscaling and cost-efficient model serving in production, with robust support for ML monitoring and experimentation
• Centralised reporting/metrics for both the business and our customers
• Powering user experience of internal and external users through agentic workflows

We are looking for an engineer passionate about developer enablement and infrastructure as code, who is eager to expand their expertise by contributing to impactful product features. You'll play a key role in improving the lives of millions of insurance policyholders globally, working with a modern and powerful technology stack that includes:

• Python for application development
• Terraform for AWS infrastructure provisioning
• Kubernetes (with Helm and Flux) for managing services
• GitLab for CI/CD and version control
• AWS as our infrastructure platform
• PostgreSQL for application data and event sourcing architecture
• Apache Flink for real-time service interactions and state management

• Collaborate with Engineers, Product Managers, and the Engagement team to understand problem spaces, contribute to solution design, and support the development of our product.
• Take responsibility for maintaining and improving parts of our backend stack, following engineering best practices.
• Write robust and well-tested code, including unit, integration, and end-to-end automated tests for backend services that power customer-facing features.
• Participate in code reviews, share feedback with peers, and stay informed about emerging backend technologies and patterns.
• Contribute to platform-related work, using infrastructure-as-code tools (AWS, Terraform, Kubernetes) to help keep our systems reliable and scalable.
• Support the growth of the team by sharing knowledge and collaborating closely with engineers and data scientists.
• Help improve engineering workflows and contribute ideas for refining team processes and delivery methods.
• Play a role in feature rollouts by using feature flags, monitoring metrics, and responding to logs and alerts.
• Embody and promote the Engineering and Sprout company values in your day-to-day work.

• Technical proficiency
• Solid proficiency in software architecture using Python and FastAPI.
• Experience working in fully cloud-hosted environments (e.g. AWS).
• Solid RDBMS experience, preferably with PostgreSQL
• Experience building RESTful APIs (e.g. FastAPI) and real-time data processing pipelines
• Bonus points for experience with Kubernetes, Apache Flink, Flux or Infrastructure-as-Code frameworks (e.g. Terraform).
• Experience of maintaining your own code in a production environment.
• A good foundational understanding of modern software development lifecycles, including code quality, pull requests, code reviews, CI/CD, QA, and production releases in an agile, fast-paced environment
• Strong problem-solving skills with the ability to think critically and creatively
• Collaborative by nature, with excellent communication and teamwork abilities
• Self-motivated, with a strong sense of ownership and accountability

• Design, develop, and deploy high-quality backend services and APIs using modern programming languages and frameworks.
• Lead the architecture and implementation of new features, ensuring scalability and maintainability.
• Collaborate closely with frontend developers, product managers, and other stakeholders to define and deliver product requirements.
• Write clean, efficient, and well-documented code, adhering to best practices and coding standards.
• Conduct code reviews, provide constructive feedback, and mentor junior engineers.
• Optimize application performance and troubleshoot complex issues.
• Stay up-to-date with emerging technologies and industry trends to drive innovation.
• Contribute to the development and maintenance of CI/CD pipelines.
• Ensure the security and integrity of our data and systems.

• Proven experience as a Senior Backend Software Engineer or similar role.
• Strong proficiency in (Specify Programming Language, e.g., Python, Java, Go, Node.js) and relevant frameworks.
• Extensive experience with database technologies (SQL and/or NoSQL).
• Deep understanding of distributed systems, microservices architecture, and cloud platforms (AWS, Azure, GCP).
• Experience with RESTful API design and development.
• Familiarity with containerization technologies like Docker and Kubernetes.
• Excellent problem-solving and analytical skills.
• Strong communication and collaboration abilities, essential for a remote role.
• Bachelor's or Master's degree in Computer Science, Engineering, or a related field, or equivalent practical experience.