Senior Software Engineer

Avallo Partners; Greater London; Hybrid; GBP 90,000 - 120,000; Full time

Job summary

Avallo is hiring a Senior Software Engineer in Greater London to lead implementation across a modern, shared stack. This hands-on role requires owning technical decisions, writing production code, and delivering scalable systems across multiple PE portfolio products.

You will design APIs and backend services, build web apps and dashboards, and integrate Stripe/Auth0 while maintaining high engineering standards in a fast-moving environment.

Qualifications

• 5+ years of professional software engineering experience with a focus on TypeScript and full-stack web development.
• Strong command of Node.js, NestJS, and Prisma — you've built and shipped production APIs.
• Solid experience with React and Next.js — you're comfortable with both the frontend and the framework.
• Familiarity with monorepo tooling; pnpm and Turborepo experience is a strong advantage.
• Experience integrating authentication systems such as Auth0 or similar.
• Comfortable working with PostgreSQL and Redis in production environments.
• A track record of writing maintainable, well-tested code and holding a high quality bar under real delivery pressure.
• Strong communication skills — you can articulate technical decisions clearly to both engineers and non-engineers.
• Able to operate independently, manage your own priorities, and take end-to-end ownership of features.

Responsibilities

• Design and build RESTful and GraphQL APIs using NestJS and Prisma on PostgreSQL.
• Develop modern web applications and internal dashboards in Next.js, React, and Vite with Tailwind CSS and shadcn/ui.
• Integrate third-party systems including Stripe, Auth0, and other client-specific tools.
• Write clean, well-tested TypeScript across frontend and backend codebases.
• Establish and improve engineering standards, patterns, and documentation across multiple product environments.
• Participate in architectural decisions and technical design reviews.
• Work directly with internal teammates and client stakeholders to translate business requirements into robust technical solutions.
• Identify and address performance, reliability, and scalability concerns proactively.
• Contribute to observability and monitoring practices using Sentry and OpenTelemetry.
• Mentor and support other engineers on the team.

Skills

TypeScript

Full-stack development

Node.js

NestJS

Prisma

PostgreSQL

Redis

React

Next.js

GraphQL

REST APIs

Monorepo tooling

pnpm

Turborepo

Auth0

Stripe

Sentry

OpenTelemetry

Tools

pnpm

Turborepo

NestJS tooling

Next.js tooling

Job description

We're hiring a Senior Software Engineer to lead implementation across our shared modern stack. This is a hands-on role for someone who owns technical decisions, writes production code, and delivers high-quality systems across multiple PE portfolio products.

Avallo partners with private equity firms and their portfolio companies to design, build, and scale software that drives measurable business value. We work across multiple products and client environments, and many of those projects are built on a shared modern stack. That gives our engineers the opportunity to move quickly, apply patterns repeatedly, and deliver high-quality systems across a range of business contexts.

We are hiring a Senior Software Engineer to help lead implementation across that stack. This is a hands-on role for someone who is comfortable owning technical decisions, writing production code, and contributing across both frontend and backend systems. You should be energized by building software from the ground up, improving engineering standards, and working in a fast-moving environment where priorities can shift across projects but the bar for quality stays high.

Our core stack includes TypeScript, Node.js, pnpm, Turborepo, NestJS, Prisma, PostgreSQL, Redis, React, Next.js, Vite, Tailwind CSS, shadcn/ui, TanStack Query, Stripe, Auth0, Sentry, OpenTelemetry, Jest, ESLint, and Prettier. Many of our engagements run on this same foundation, so we are looking for an engineer who can operate confidently within these tools and patterns while helping evolve them over time.

In this role, you will design and build APIs and backend services, develop modern web applications and internal dashboards, integrate third-party systems such as Stripe and Auth0, and help shape the standards we use across multiple products. You will be expected to think beyond implementation alone, making sound technical tradeoffs, improving maintainability, and helping ensure that what we build is scalable, reliable, and aligned with business goals.

You will work closely with internal teammates and client stakeholders to translate ideas into practical technical solutions. That means strong communication matters as much as strong execution. The right person for this role is comfortable moving between product discussions, architectural decisions, and hands-on development without losing momentum or attention to detail.

This is a strong fit for an engineer who combines technical depth with a product mindset. We value people who take ownership, care about quality, and can help raise the level of the team while still moving quickly. If you enjoy solving real business problems, working across a modern full-stack environment, and building software that has visible impact, this role is for you.

What you'll do

• Design and build RESTful and GraphQL APIs using NestJS and Prisma on PostgreSQL
• Develop modern web applications and internal dashboards in Next.js, React, and Vite with Tailwind CSS and shadcn/ui
• Integrate third-party systems including Stripe, Auth0, and other client-specific tools
• Write clean, well-tested TypeScript across frontend and backend codebases
• Establish and improve engineering standards, patterns, and documentation across multiple product environments
• Participate in architectural decisions and technical design reviews
• Work directly with internal teammates and client stakeholders to translate business requirements into robust technical solutions
• Identify and address performance, reliability, and scalability concerns proactively
• Contribute to observability and monitoring practices using Sentry and OpenTelemetry
• Mentor and support other engineers on the team

What we're looking for

• 5+ years of professional software engineering experience with a focus on TypeScript and full-stack web development
• Strong command of Node.js, NestJS, and Prisma — you've built and shipped production APIs
• Solid experience with React and Next.js — you're comfortable with both the frontend and the framework
• Familiarity with monorepo tooling; pnpm and Turborepo experience is a strong advantage
• Experience integrating authentication systems such as Auth0 or similar
• Comfortable working with PostgreSQL and Redis in production environments
• A track record of writing maintainable, well-tested code and holding a high quality bar under real delivery pressure
• Strong communication skills — you can articulate technical decisions clearly to both engineers and non-engineers
• Able to operate independently, manage your own priorities, and take end-to-end ownership of features

Nice to have

• Experience working across multiple simultaneous products or client engagements
• Familiarity with Stripe Billing, Connect, or usage-based pricing models
• Exposure to private equity or technology consulting environments
• Experience with TanStack Query, Zod, or similar libraries in our stack
• Understanding of observability patterns using OpenTelemetry
• Prior involvement in establishing engineering standards, onboarding processes, or internal tooling