Senior Full-Stack Software Engineer

PAIR; Greater London; Hybrid; GBP 90,000 - 130,000; Full time

Benefits offered by this job

Equity

Hybrid schedule

Anchor weeks

Holidays

Visa sponsorship

Job summary

PAIR is hiring a Senior Full-Stack Engineer to lead development across frontend and backend. You will build high-quality features, own critical technical decisions and mentor peers in a hands-on, non-managerial capacity.

You will shape architecture and standards for a modern web platform, collaborating with product and design to deliver scalable, AI-powered solutions in a hybrid London-based team.

Qualifications

• Must have proven senior engineering experience building production web platforms across frontend and backend.
• Hands-on with at least one modern frontend framework (Vue, React or Angular).
• Deep experience building APIs and backend services in a modern language (Python preferred).
• Solid experience with relational databases.
• Ability to own technical decisions and trade-offs across a product area.
• Collaborate closely with product and design to deliver user-centric features.
• Experience harnessing AI-native ways of working to ship quickly while maintaining quality.

Responsibilities

• Build end-to-end product features across frontend and backend.
• Set standards for full-stack quality, testing and design.
• Translate customer needs into robust, user-facing functionality with the team.
• Make pragmatic technical decisions across frontend architecture, APIs and data models.
• Improve platform quality, usability, performance and reliability as adoption grows.
• Own key product areas and connect AI-powered flows, content, authentication and UX.

Skills

Senior engineer

Frontend and backend

Modern frontend framework

APIs and backend services

Relational databases

Technical decision making

Collaboration with product/design

AI-native working practices

Job description

Who We Are

PAIR is a fast-growing AI adoption startup on a mission to help professionals and teams harness AI to do their best work. Our platform delivers personalised, AI-powered learning experiences and adoption support that help organisations rapidly harness AI at scale.

We've already achieved:

• 30,000+ users
• Major enterprise deployments live today with the likes of the Ministry of Justice, you.com and PWC
• Backing from top-tier UK investors including Seedcamp, Venrex, Tom Hulme (Google Ventures) & Steve Garnett (ex-Chairman EMEA, Salesforce)
• US Expansion

We're a small, high-calibre team that ships fast. Engineers here have a direct and visible impact on the product, users, and company trajectory. If you want meaningful ownership and an environment that values great engineering, you'll thrive.

You'll be joining shortly after our Seed round, at a point where the core product is proven and live with enterprise customers, with huge scope to shape product, architecture, standards and technical direction as we take the platform to the next level.

The Role

We're hiring a Senior Full-Stack Engineer to help lead the development of our product platform across frontend and backend. You'll be responsible for building high-quality end-to-end product features while raising the bar for how we design, build and ship reliable software across the stack.

This is a hands-on senior engineering role: you'll write production code, own key technical decisions, work closely with product and design, and mentor other engineers, without people management responsibilities.

You'll:

• Build end-to-end product features, transforming how organisations adopt AI
• Set standards for full-stack quality, testing, maintainability and technical design
• Work closely with the CTO, Director of Engineering, product and design to translate customer needs into robust, user-facing functionality
• Make pragmatic technical decisions across frontend architecture, API design, data modelling and integrations
• Improve the quality, usability, performance and reliability of the existing platform as usage grows
• Own the full-stack role of key product areas, connecting AI-powered flows, learning content, authentication, core platform capabilities and user experience

Our Stack

Frontend: Vue 3, TypeScript

Cloud: Azure as primary (plus a small number of services on GCP)

Infra & DevOps: Terraform, GitHub Actions, OpenTelemetry

You don't need to know this exact stack, but you should be very comfortable working across a modern web application and able to make sound technical decisions across both frontend and backend systems in production.

What We're Looking For

Must-have experience

• Strong track record as a senior engineer building production web platforms across frontend and backend
• Strong experience with at least one modern frontend framework (Vue, React or Angular)
• Deep experience building APIs, backend services and data-driven product features in a modern language (Python preferred, but strong experience elsewhere is acceptable)
• Solid experience working with relational databases
• Comfort being the go-to person for technical decisions and trade-offs across a product area
• Comfort working closely with product and design to shape practical, user-centred solutions
• Proven skills harnessing AI-native ways of working to ship quickly without sacrificing quality

Nice to have

• Vue and TypeScript experience
• Python + FastAPI experience
• Experience with multi-tenant SaaS systems
• Familiarity with cloud platforms (Azure, AWS or GCP)
• Experience working in a startup or small product team

Why Join PAIR?

Real impact:

You'll help shape the product platform that enterprise customers rely on to stay relevant in the age of AI.

Ownership:

This is not a narrow role: you'll have real technical authority and responsibility across the stack.

Work closely with the product:

You'll collaborate directly with product and design and see how your work impacts customers.

A-player environment:

We hire carefully. You'll work with thoughtful, driven engineers who care about their craft.

AI-native organisation:

We practice what we preach and invest the time to make sure that we are harnessing AI across our business as our competitive advantage.

Backed by top investors:

Strong financial footing and backing from some of the best with meaningful revenue traction.

Mission:

Help people and organisations use AI confidently, not fear it

Compensation & Working Setup

• Equity: £53k at current market value, vested over four years
• Hybrid: 1 day/week in our central London office (Tuesdays)
• 7 company-wide Anchor Weeks (in-person Mon-Thu) each year for deep collaboration
• 25 days holiday + public holidays
• Right to work: We can sponsor visas for exceptional candidates; applicants normally have UK work rights

Hiring Process

We keep the process simple and respectful of your time.

• Application form - basic details, skills matrix and a short case-study question.
• 30 minute introductory Teams call to talk about PAIR, the role, and how you might fit into it
• Technical interview (remote) - a practical exercise to see your hands-on coding experience
• Final stage - meet the team in person, take on a system design challenge, and talk about how you'd help us scale PAIR over the next 12-24 months