Top Tech Jobs & Startup Jobs in London

Serves as the CEO’s strategic partner, translating priorities into organizational alignment and decision-ready actions. The Chief of Staff filters issues for CEO attention, supports executive leadership coordination, prepares the CEO for Board and external engagements, represents delegated authority, and aligns Investment Committee work with Foundation strategy. The role influences without formal authority, drives cross-functional priorities, manages high-stakes information, and supports governance, fundraising, and major organizational decisions.

Sells Mozilla’s digital advertising products to Fortune 500 brands and agencies across the UK and Europe. Responsibilities include developing client relationships, prospecting, managing sales pipelines, meeting revenue targets, presenting advertising solutions, analyzing campaign performance, maintaining CRM records, and communicating client feedback to product and marketing teams.

Analyze Gecko browser engine telemetry across Desktop and Android, build leadership dashboards, identify telemetry gaps, develop frameworks to remove bot and hardware noise, and correlate performance metrics with user behavior. The role requires advanced SQL, statistical analysis, data visualization, browser component knowledge, and independent problem solving to translate engineering data into product strategy.

Implement and ship Storage Encryption Everywhere in Firefox/Gecko, including schema migrations, encrypted data storage, integration and platform testing. Collaborate through code review, resolve specification questions, and shepherd the feature across Nightly, Beta, and Release. Diagnose and fix correctness, performance, and regression issues in a multithreaded browser-engine codebase while contributing openly through public bugs and upstream landing.

Design, build, deploy, and operate software and systems supporting Firefox engineering. Develop developer tooling, CI/CD, workflow automation, and AI-assisted development tools. Own complex problems across software, cloud, and operations while improving reliability, performance, observability, and cost efficiency. Collaborate across engineering and infrastructure teams, use telemetry and metrics for technical decisions, contribute to architecture and strategy, and help establish reusable operational standards and patterns.

Develop privacy, anti-tracking, and phishing protections for Firefox and improve the Gecko browser engine. Build performant, low-latency C++, Rust, and JavaScript software while independently delivering complex features within release windows. Collaborate asynchronously with a distributed international team and communicate technical decisions clearly.

Improve Firefox Gecko’s Session History reliability by expanding Web Platform and Gecko mochitest coverage, debugging failures, fixing correctness issues, and landing changes through code review. The role requires substantial browser-engine experience, strong C++ and JavaScript skills, and comfort working with public bugs, module owners, and upstream development processes.

Diagnose and verify long-tail Firefox WebCompat bugs, reproduce and triage site-breakage reports, write WebCompat interventions, and implement simple AI-assisted fixes. The role converts reported breakages into actionable or resolved bugs and requires strong HTML, CSS, JavaScript, browser DevTools, and cross-browser debugging skills.

Lead and mature Mozilla's ISMS and compliance programs (ISO 27001 and SOC 2 Type 2). Manage SoA, risk treatment, audits, policy lifecycle, gap remediation, internal audits, and cross-functional control ownership while advising security leadership on certification readiness and compliance strategy.

Design, implement, test, and ship Firefox security and hardening features for enterprise users. Improve browser security architecture across operating systems, including privilege isolation, trust boundaries, cryptographic protocols, WebPKI, and security-sensitive web APIs. Investigate security issues, deliver maintainable fixes, and resolve stability, correctness, performance, memory, and multithreading challenges in a complex native codebase.