Data Lead

Who we areWe create outsized returns through hands-on delivery of designed solutions. We bring together strategy, product, design, engineering and data to solve the hardest problems in financial technology. We work as one accountable team, and own outcomes rather than outputsWe are leading the transformation with one of the UK’s largest financial services firms; a global trading platform with ambitions far beyond its current business. We are reshaping how it develops products, creates value, builds technology and uses data to make decisions. You will be Sumara’s second data hire embedded within that transformationWhat this isThis is not a reporting or support role. We focus on hard skills and ownership: you will join the foundational squad and own the establishment of the data foundations for the future of the company. This squad covers the foundations everything else will stand on: authentication, onboarding, and accounts. Every existing customer will pass through the systems this team builds.You are the direct analytical partner to the engineering squads building these core services. Your mandate is to embed within the Software Development Lifecycle (SDLC) and ensure that every microservice, API, and frontend component is rigorously instrumented, monitored, and measured.Why this role is rareEngineering squads move fast, but they often lack a native event-tagging and experimentation culture. You are not a passive reporter waiting for requirements or building dashboards on request. You are an active, vocal participant in ceremonies. Talk to backend developers, challenge release features, demand quality monitoring, control experiments, and hold the line on telemetry. You will pave the road for others to follow you.The starting stateYou are stepping into a high-velocity squad (alongside backend leads) tasked with critical migrations, such as integrating legacy users via Auth0. You will bridge the gap between backend system performance and user-facing behavioral analytics, turning raw event streams into signals the team actually acts on.What you ownIdentity & Session Stitching: You own the logic that tracks user behavior across microservices, APIs, and third-party tools. Your primary challenge is stitching sessions as users transition from an unauthenticated state into a fully mapped, authenticated account.Observability & User Monitoring: You manage the intersection of system performance and user friction. Using tools like AWS RUM, Datadog, New Relic, Amplitude, etc, you track client-side errors, app crashes, and latency spikes to identify exactly what is frustrating the user.Auth & Onboarding Funnel Analysis: You monitor the critical pathways. It is your responsibility to identify native mobile/web callback configuration errors and to track linked account failures, ensuring the Auth0 migration funnel is watertght.What you drive in partnershipQA & Sprint Ticket Auditing: You live alongside the developers, audit sprint tickets to ensure behavioral telemetry and event-tagging requirements are built into the definition of done before code ships.API Event Ingestion & Streaming: Because this squad is backend-heavy, you partner with infrastructure to manage the ingestion of high-volume event streams (utilizing AWS Kinesis, Kafka, etc.), ensuring the analytics pipeline scales with core service traffic.Feature Success Metrics: You define what "success" looks like in production. Whether it is a new investments feature or a new view of account data, you define the metrics and set up the A/B testing infrastructure to measure impact.How you operateYou are an active voice in engineering ceremonies. You promote an A/B testing and telemetry culture where it previously didn't exist. You use AI and modern data stack workflows to automate anomaly detection and QA processes, freeing you up to focus on architecture and strategy.What success looks like No feature ships without validated event-tracking and performance monitoring attached to its ticketIdentity resolution holds end to end; a user's journey stays stitched from anonymous app download to funded, authenticated accountEngineering leadership relies on your observability stacks to catch callback errors and client crashes before they impact board-level metricsA/B testing, experimentation and enriched data outputs become default engineering practices, not afterthoughts.RequirementsWhat we are looking forRequired:5+ years in analytics engineering, devops, or data engineering, working directly alongside software engineering squads.Deep expertise in identity stitching and session management, particularly in complex Auth0/migration environments.Hands-on experience with observability and APM tools (Datadog, New Relic) combined with behavioral analytics (Amplitude, Mixpanel).Working knowledge of event streaming pipelines (AWS Kinesis, Kafka) and how backend events translate to product analytics.A track record of embedding into agile/SDLC workflows (Jira, Trello, Linear) and enforcing data QA standards.Strong SQL/Python skills for complex data transformation and workflow automation.Strong Signal:Experience in multi-product fintech or trading platforms dealing with legacy tech migrations.Familiarity with modern deployment practices and how to instrument backend microservices/monolith structures.Comfort pushing back on senior engineers and demanding rigorous data standards before a release.BenefitsCompetitive salary commensurate with experienceMarket standard EOSB and performance bonusesComprehensive health insuranceProfessional development and conference budgetsTeam building events, career mentorship, and strong company cultureRemote work flexibility