Web Infrastructure Engineer

Methodfi; Greater London; On-site; GBP 95,000 - 125,000; Full time

Job summary

A forward-thinking tech company in Greater London seeks a Web Infrastructure Engineer to enhance their AI-native CRM infrastructure. Responsibilities include leading performance initiatives for frontend and backend, optimising build processes, and defining best practices. The ideal candidate will have deep expertise in JavaScript and TypeScript, strong communication skills, and familiarity with performance tooling. The position offers a competitive salary of £95,000 to £125,000 along with attractive benefits including equity and enhanced family leave.

Benefits

Competitive salary

Equity in an early-stage tech company

25 days holiday plus local public holidays

Apple hardware

Private medical insurance

Pension contribution

Enhanced family leave

Team off-sites in fun places

Qualifications

• Deep expertise in JavaScript and TypeScript performance on both client and server.
• Proven experience designing and optimising internal API and service-layer architecture.
• Strong familiarity with performance tooling like Chrome DevTools and APM platforms.
• Strong understanding of frontend performance patterns and caching strategies.
• Experience using RUM to guide performance improvements.

Responsibilities

• Lead initiatives to improve frontend and backend performance.
• Identify and eliminate bottlenecks in Node.js services.
• Build and integrate metrics and performance dashboards.
• Optimise dependency management and CI/CD pipelines.
• Define internal best practices for web infrastructure.

Skills

Deep expertise in JavaScript and TypeScript performance

Experience designing and optimizing API architecture

Familiarity with performance tooling

Understanding frontend performance patterns

Experience using Real-User Metrics (RUM)

Systems-level understanding of build pipelines

Excellent communication skills

Job description

Attio is on a mission to redefine CRM for the AI era.

We’re building the first AI-native CRM — designed for the most ambitious go-to-market teams. We recently announced our $52M Series B, led by GV (Google Ventures), with support from Redpoint, Balderton, Point Nine, and 01A. Our team thrives on solving complex technical challenges, delighting our users, and setting a new standard for the industry.

About the role

Our engineering team tackles the toughest challenges so our users never have to. Real-time infrastructure, AI-native architecture, and a frontend that feels effortless — all powered by a team that moves fast, thinks rigorously, and holds an exceptionally high bar for quality.

We’re looking for a Web Infrastructure Engineer who lives and breathes the systems, runtimes, and tooling that enable engineers at Attio to ship fast and confidently. You’ll own performance across the stack — from the Node.js runtime and TypeScript pipelines to client-side rendering, bundling, and real-user metrics — and help shape the web infrastructure that powers Attio’s product.

What you’ll do

• Lead initiatives to improve performance in both the frontend (React, web workers, bundling) and backend (Node.js runtime, TypeScript pipelines, and I/O efficiency)

• Use profiling and benchmarking techniques to identify and eliminate bottlenecks and memory leaks in our Node.js services and client-side application code

• Build and integrate metrics, tracing, and performance dashboards to make performance data accessible and actionable across teams

• Reduce build and CI/CD overhead by optimising dependency management, incremental builds, caching strategies, and monorepo workflows

• Define internal best practices, guidelines, and tooling for the web infrastructure that scale with the company

• Represent Attio’s Product & Engineering values both internally and externally

What you'll bring

• Deep expertise in JavaScript and TypeScript performance on both client and server, including event-loop behaviour, garbage collection, async I/O, and memory management

• Proven experience designing and optimising internal API and service-layer architecture — particularly frameworks that coordinate data fetching, caching, and state management across large React/TypeScript codebases.

• Strong familiarity with performance tooling such as Chrome DevTools, Node profiler/inspector, flamegraphs, Lighthouse, APM platforms, and runtime exploration tools

• Strong understanding of frontend performance patterns (lazy loading, route-level splitting, bundle analysis, caching strategies, web workers)

• Experience using Real-User Metrics (RUM) to guide and prioritise performance improvements, and comfort working with tools such as Datadog, Sentry, Prometheus, Grafana, or OpenTelemetry

• Systems-level understanding of build and CI/CD pipelines (Yarn, pnpm, npm, esbuild, Vite, Turborepo, Rsbuild, incremental builds)

• Excellent communication skills and the ability to influence engineers across product teams to align on performance strategy

Nice to have:

• Experience with React internals, reconciliation debugging, or custom performance instrumentation

• Contributions to open-source infrastructure projects, performance tooling or JavaScript/TypeScript runtimes

• Familiarity with TypeScript compiler internals, V8 engine behaviour, or WebAssembly tooling

• Familiarity with Go, Rust and native profilers such as dtrace, xctrace and Linux perf

• Experience optimizing large-scale real-time or collaborative web applications

What we offer

• Competitive salary of £95,000 to £125,000

• Equity in an early-stage tech company on an incredible trajectory

• 25 days holiday plus local public holidays

• Apple hardware

• Private medical insurance through AXA

• Pension contribution through Hargreaves Lansdown

• Enhanced family leave

• Team off-site in fun places! (We've been to Barcelona, Lisbon, Malta, and Split so far)