Senior software engineer fullstack Work, Jobs in London (with Salaries)

Senior Fullstack Software Engineer
Outsmart Insight —London
- Weekend availability
- Hybrid work
- AI
Senior Fullstack Engineer (Python + React.js)
Parser Limited —London
- Full-time
- Hybrid work
- Computer Science
- Engineering
- AWS
Quick apply
Senior/Staff Fullstack Engineer, Backend Leaning
Synthesia —London
- £130 an hour
- Full-time
- Remote
- Leadership
- Communication skills
Fullstack Senior Software Engineer (TypeScript, C#, React, AWS)
Alto —London
- Full-time
- Hybrid work
- AWS
- AI
- Annual leave
- Referral programme
Quick apply
Senior Fullstack Engineer, Scale
Airwallex —London
- £74,822 - £138,955 a year
- Full-time
- Hybrid work
Senior Fullstack Developer — Java or Kotlin, React and TypeScript
Zühlke —London
- Full-time
- Travel
- APIs
- Agile
Senior Fullstack Software Engineer (.NET/Java)
Sky —London
- Full-time
- Hybrid work
- Mentoring
- Communication skills
Software Engineer
Murphy AI —London
- £50,000 - £100,000 a year
- Hybrid work
- AI
- Communication skills
Quick apply
14d
Fullstack Software Engineer
MLabs —London
- Full-time
- Computer Science
- Master's degree
- In-person
Quick apply
Senior Full Stack Engineer
Macrobond Financial AB —London
- Full-time
- Agile
- AI
- Life insurance
Senior Backend Engineer
BRAHMA —London
- Master's degree
- Machine learning
- APIs
12d
Senior AI Fullstack Engineer – Cloud Applications
HiveMQ GmbH —London
- £58,000 - £110,000 a year
- Full-time
- Remote
- DevOps
- Master's degree
- AWS
Quick apply
Senior/ Staff Software Engineer
Healthtech-1 —London
- £90,000 - £130,000 a year
- Overtime
- AI
- School
- Annual leave
- Work from home
Staff/Lead Fullstack Engineer (Frontend-focused)
Mimica —London
- Full-time
- Remote
- English
- Communication skills
- Annual leave
- Flexible schedule
Senior Fullstack Engineer
Capsa AI —London
- Full-time
- AI
Quick apply
Fullstack Engineer (Frontend focus)
CoreWeave Europe —London
- Machine learning
- AI
- Employee assistance programme
Quick apply
Senior Fullstack Engineer, Vendor Risk Management - UK
Vanta —London
- Full-time
- Hybrid work
- AI
- Communication skills
- Annual leave
Senior Fullstack Engineer, Vendor Risk Management
Vanta —London
- Full-time
- Hybrid work
- Leadership
- Communication skills
- Annual leave
Senior AI engineer
Healthtech-1 —London
- £90,000 - £130,000 a year
- Overtime
- AI
- School
- Annual leave
- Work from home
Senior Full Stack Engineer
Xapien —London
- £100,000 - £105,000 a year
- Full-time
- Hybrid work
- Software troubleshooting
- Communication skills
- Life insurance
Quick apply

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senior software engineer fullstack jobs near london

Senior Fullstack Software Engineer

Outsmart Insight
London

Apply Now

Job details

Qualifications

Data modelling
Cloud infrastructure
Relational databases
NoSQL
Back-end development
REST
AI
Debugging

Full job description

The pitch. It’s a serious engineering role with a great team – and meaningful responsibility.

This is not a narrow “ticket-closing” developer job.

You won’t be handed tightly scoped Jira tasks inside a heavily layered team structure. You won’t be maintaining a disposable MVP. And you won’t be managing people.

Instead, you’ll be working on the core platform that underpins Outsmart’s crowdsourcing operations – a mature, revenue-generating system that has evolved over years and continues to scale.

If you enjoy owning real systems, thinking architecturally, improving legacy code thoughtfully rather than rewriting it, and being trusted to deliver without heavy supervision, this role will feel unusually well-matched.

The role

As Senior Fullstack Software Engineer, you will help design, build and maintain the production systems that power Outsmart’s platform.

You’ll work closely with our CTO, operating as a high-agency individual contributor with genuine ownership across backend systems, infrastructure and platform evolution.

This is a role for someone who wants to:

Work on real, live systems with meaningful operational responsibility
Make architectural decisions, not just implement them
Improve and extend an existing platform with care and judgement
Help shape the engineering foundations for the next stage of company growth

You will be trusted to take product and operational requirements and translate them into robust, production-ready solutions.

What you’ll be doing

Designing and maintaining backend services primarily in Python
Developing and evolving well-structured RESTful APIs
Designing and improving data models across relational (e.g. PostgreSQL) and NoSQL databases
Working across the stack where needed, including JavaScript, modern HTML/CSS, and utility frameworks such as Tailwind
Contributing to cloud-based infrastructure (e.g. Google Cloud), deployment pipelines and DevOps practices
Debugging live production issues with a calm, root-cause mindset
Incrementally improving system architecture using sound design principles (including modular design, DDD-style thinking, and pragmatic architectural patterns)
Reviewing code, raising standards constructively, and contributing to a disciplined engineering culture
Leveraging modern tooling (including AI-assisted development) to improve quality and velocity

This is not greenfield experimentation. It is thoughtful, high-quality engineering on systems that matter.

The environment

We are a small, intellectually serious company. That has advantages and responsibilities.

You will:

Speak directly with senior decision-makers when needed
Operate without perfect documentation
Balance speed with long-term maintainability

This role suits someone comfortable with autonomy, accountability and cross-functional collaboration.

Who this role is for

This role is designed for someone who is:

8–15 years into their engineering career
Has worked in a small company (c. 5–30 people) or similarly lean environment without heavy process
Experienced in inheriting and improving mature systems
Comfortable reading and navigating complex legacy code
Strong in systems thinking (trade-offs, scalability, cost implications)
Backend-heavy, with strong Python expertise
Operationally mature – you’ve supported production systems, not just built features

You are likely:

Calm under pressure
Direct but not ego-driven
Curious and thoughtful rather than dogmatic
Comfortable challenging ideas constructively

If you primarily identify as a manager, a greenfield-only builder, or someone who prefers heavy structure and layered sign-off, this role is unlikely to be a good fit.

Practicalities

Schedule: Monday to Friday
Weekends: No
Location: UK-based
Working style: Hybrid (remote and London office)

Why Outsmart Insight?

Outsmart Insight operates at the intersection of technology, intelligence and large-scale coordination. Our internal platform powers a global network and supports complex, high-trust client engagements.

We are deliberately serious about quality, reliability and long-term thinking.

As we grow, we are investing in strengthening our engineering foundations – building systems that are robust, scalable and thoughtfully designed.

If you want to work somewhere where your engineering judgement genuinely matters, this is that opportunity.

Our values

Smart minds, working together
Quality delivered every time
Strong client relationships built on trust
Hard work, rewarded
A happy, healthy team

Apply

Send a short cover letter and a two-page CV to [email protected], outlining why this role, and this type of engineering work, appeals to you.

Please note: only applications sent directly to this email address will be considered.

Apply

Send a two-page CV to [email protected] highlighting your suitability for this role.

Apply Now

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The role

What you’ll be doing

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Who this role is for

Practicalities

Why Outsmart Insight?

Our values

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