Senior/Staff Data Engineer

9fin

About 9fin 9fin is the AI platform powering global debt markets — the world’s largest asset class at over $145 trillion. Debt markets are vast, global, and mission-critical, yet still run on fragmented data, PDFs, and manual workflows. 9fin replaces this broken infrastructure with a single platform that centralises proprietary credit data, deep analysis, and high-value workflows across global markets. Today, 9fin powers teams at 300+ blue-chip institutions worldwide, including global banks, asset managers, private equity firms, law firms, and advisors. The business is scaling at exceptional speed, with rapid expansion in the US and best-in-class retention driven by deep workflow adoption. We’re at a defining inflection point. With proven product-market fit and strong, global market pull, 9fin is accelerating toward becoming the category-defining platform for debt markets worldwide. We're looking for a Senior Engineer II to take broad technical ownership of the backend systems powering 9fin's platform. You will sit between our Senior and Staff engineering tracks. You will own meaningful systems end to end, lead multi sprint initiatives across a product domain, and shape how we build for scale. You will operate as a strong senior IC, leading design, raising the engineering bar through review and mentorship, and partnering closely with Product, Data, and our financial and legal domain experts. This role suits someone who has already grown beyond a typical senior remit. You enjoy diving into distributed systems problems, and you have firsthand experience scaling services under real production load. WHAT YOU'LL DO * Own the design and delivery of significant backend systems and services across a product domain, from data modelling through API surface to operational concerns. * Lead complex, multi sprint engineering initiatives that span several engineers and stakeholders. * Drive scaling work: identify bottlenecks, propose architectural changes, and execute migrations safely in production. * Make pragmatic decisions about distributed systems concerns including consistency, idempotency, partitioning, retries, and observability. * Contribute to platform level discussions on service boundaries, data ownership, and how systems evolve as we enter new markets. * Run thorough code reviews, mentor senior and mid level engineers, and help define what good looks like in the codebase. * Partner with cross functional teammates from Product, Data Engineering, and our editorial and legal domain experts to scope work and ship the right thing. * Improve developer experience by investing in tooling, testing, observability, and the paved road so the whole team moves faster. * Ramp on legacy areas of the system, find the highest leverage cleanup, and execute it without stalling delivery. * Use AI assisted engineering to move faster on understanding, prototyping, and shipping code. OUR BACKEND STACK * Python is the dominant backend language. * Flask and FastAPI, with strong typing and Pydantic powering automated documentation and API definitions. * PostgreSQL at the heart of most services. * AWS for cloud hosted services, with heavy use of AWS Lambda serverless. * Docker on AWS ECS for uniform development and deployment. * Internal developer platform with a standardised paved road from code to production, plus managed preview environments and feature flags. WHAT WE'RE LOOKING FOR You will be a great fit if you have: * Several years operating as a senior backend engineer, with a clear track record of leading technical initiatives end to end across a product domain. * Experience contributing to the design of distributed systems in production, including the operational realities such as failure modes, observability, data consistency, and graceful degradation. * A track record of solving scaling problems, whether database scaling, throughput, latency, or cost. You can talk through a real example end to end: how you measured the problem, what you changed, and what the outcome was. * Experience designing and operating event driven architectures in production, including message queues or streaming systems, with a clear understanding of delivery guarantees, idempotency, and failure handling. * Strong design skills around APIs, service boundaries, and the flow of data from persistent storage through to clients. * Strong Python experience, including modern web frameworks (we use FastAPI with Pydantic and strong typing). * Deep working knowledge of SQL and relational data modelling. * Excellent collaboration and communication, including the ability to explain complex systems and tradeoffs to non technical stakeholders. * A strong product and customer mindset, with the judgement to balance shipping value against long term system health. * A high bar for code quality, testability, and operational maturity, and the habit of raising that bar through review and mentorship. Nice to have: * Experience working on complex permissioning or access control systems (multi tenant, role or attribute based, fine grained, audit driven, or similar). * Experience with end to end document management systems, especially solving problems of scale and applying strong security practices such as encryption, access control, data lineage, and retention. * Experience modernising legacy systems and migrating workloads with minimal downtime. * Experience with a data pipeline orchestrator. * Experience working at AI startups, including integrating with and building on top of AI and LLM based solutions. COMPANY BENEFITS We’re a scaling start up and we enjoy sharing our success, when the company succeeds, we always reinvest that in our people. We also offer huge amounts of responsibility, an abundance of opportunity for growth and a platform to truly excel. Financial & Insurance * Competitive Salary(our salary bands are benchmarked at the top end of the market) * Pension (your minimum contributions are 4% with 9fin matching up to 7%) * Private Medical Insurance * Paid sick leave with Income Protection for long periods of illness * Group Life Assurance * Season Ticket Loan&Cycle to Work schemes Time off * 25 holiday days per year * Local public holidays (with the ability to exchange them for alternative days) * Hybrid working model, to allow you the flexibility to decide how, where and when you do your best work * Work abroad for up to 3 months a year * 1 month paid sabbatical after 5 years of service * Enhanced parental leave&flexible working arrangements available Training & Culture * Professional learning and development budget * Quarterly team socials * Summer and Winter company social events 9fin is an equal opportunities employer At 9fin we are dedicated to building and promoting a fair and inclusive workplace where everyone can reach their full potential and truly belong. We recognize that building diverse teams enables a more creative and productive environment. If you’re excited about this role but your experience doesn’t perfectly align with the job description, we encourage you to apply anyway. You might just be who we’re looking for — either for this role, or perhaps another.

Marshmallow

We’re on a mission to make migration easy. We started building Marshmallow in 2017. Since then, we’ve grown from 3 to 700+ people, gained unicorn status, raised ~£140M over three funding rounds, turned profitable, insured millions of drivers and lent millions in car loans. But we’re only just getting started. Our goal is to become one of the largest financial services providers in the world. Over the next 10 years we’ll grow exponentially, not only by scaling our existing products, but also by building new ones. To achieve our goals we need incredibly ambitious, commercially driven people who never settle for ‘good enough’. Marshmallowers are hungry for autonomy and ownership, and would rather improve than coast. Everyone raises standards and has an impact, with a focus on collective success over self-interest. We’ve created an environment where curious, tenacious people win and grow together. If that sounds motivating, this could be the place for you. LONDON (HYBRID, 3 DAYS IN OFFICE) DATA SCIENCE AT MARSHMALLOW Our Data Science team partners across the business to turn data into better decisions, smarter products, and simpler customer journeys. We work closely with Product, Engineering, and Operations to build and ship models and AI systems that are reliable in production and deliver measurable impact. Within Data Science, this role sits in Claims, supporting the function and the broader ambition to automate more of the claims journey. Claims is one of Marshmallow's most important customer touchpoints, and we're looking for a Staff Data Scientist who can provide technical leadership across traditional ML and Generative AI, bring system-level thinking to how we scale decisioning, and confidently challenge proposals to ensure we build robust, sustainable solutions. WHAT YOU'LL BE DOING * Provide technical leadership for data science across Claims Fraud, shaping the approach to risk decisioning and fraud detection in partnership with Product and Engineering * Design, build and iterate on production ML and Generative AI/LLM systems that support claims validation and automation * Collaborate closely with other Claims data scientists to bring system-level thinking to how models, data and workflows fit together, identifying architectural improvements needed to scale decisioning and reduce time-to-production * Be vocal about the platform and tooling investments needed (monitoring, feedback loops, QA) to achieve AI-driven end to end claims automation * Advocate for robust, scalable, and strategically aligned technical solutions in cross-functional discussions, ensuring current systems and infrastructure contribute to the multi-year vision for automated claims handling * Set a high bar for statistical rigour, experimentation and measurement, helping improve how Claims performance and uncertainty are understood and communicated to senior stakeholders WHO YOU ARE * You think in systems: you can connect the dots between data science, engineering, and product to shape scalable solutions that build on each other over time. * You're confident in challenging assumptions and pushing for the right approach, using strong communication skills to influence stakeholders across seniority levels and disciplines with clear, pragmatic reasoning. * You thrive in ambiguity and change, staying resilient and effective during transitions while bringing structure, clarity, and momentum to complex problem spaces. * You're motivated by real-world impact, partnering closely with cross-functional teams to drive meaningful automation and better customer outcomes across the claims journey. WHAT YOU'LL BRING * Significant commercial experience delivering end-to-end Machine Learning solutions, from problem framing and experimentation through to production deployment and ongoing monitoring * Hands-on experience building and shipping Generative AI systems in production (not just prototypes), including evaluation, safety/quality considerations, and integration into customer or operational workflows * Strong statistical and modelling foundation, with experience in risk-based decisioning under uncertainty (e.g., fraud, credit, insurance, or other regulated domains) * Proven ability to influence technical direction across Data Science and Engineering, including shaping scalable model/service integration patterns and challenging proposals to drive robust, long-term solutions * Strong stakeholder management skills, with confidence communicating trade-offs and pushing back constructively with Product and Engineering to ensure high-quality outcomes PERKS OF THE JOB * Bonus scheme designed to reward high performance * Private medical insurance with Vitality, mental health support with Oliva * Personal learning budget and 2 dedicated L&D days a year * Monthly flexible benefits budget to spend as you choose * 25 days holiday plus bank holidays * 4 weeks Work From Anywhere per year We are able to offer visa sponsorship for this position. OUR PROCESS * Initial call with a member from our Talent Team (30 mins) * Past Experience interview with Hiring Manager (60 mins) * Systems Design & Technical interview with a couple of the team (90 mins) * Culture interview (60 mins) Diversity of thought We know the best ideas come from having different perspectives in the room - and we're committed to hiring fairly, regardless of background, identity or experience. If you see yourself in this role, we'd encourage you to apply.

Databricks

P-1127 At Databricks, we are obsessed with enabling data teams to solve the world's toughest problems, from security threat detection to cancer drug development. We do this by building and running the world's best data and AI infrastructure platform, so our customers can focus on the high value challenges that are central to their own missions. Our engineering teams build highly technical products that fulfill real, important needs in the world. We develop and operate one of the largest scale software platforms. The fleet consists of millions of virtual machines, generating terabytes of logs and processing exabytes of data per day. At our scale, we regularly observe cloud hardware, network, and operating system faults, and our software must gracefully shield our customers from any of the above. The Delta DML team owns the core write-path operations for Delta Lake, the open-source storage layer behind the Databricks Lakehouse. Our mission is to deliver industry-leading performance and a seamless user experience at massive scale, with most data written in Databricks flowing through our platform.  We drive performance innovations like Low Shuffle Merge and Deletion Vectors and actively contribute to open source efforts to unify Delta and Iceberg formats. We are seeking a highly skilled and experienced Senior Staff Software Engineer to join our backend team. In this role, you will be instrumental in designing, developing, and maintaining robust backend systems that power Databricks workspaces. You will build the next-generation platform for serving workspace assets, ensuring high QPS, low latency, reliable, and performant systems, proactively addressing the future growth challenges. Additionally, as a senior member of the team, you will provide technical leadership, mentorship, and guidance to junior engineers, contributing to the overall improvement of team coding practices and system designs. The Impact you will have: * Solve real business needs at large scale by applying your software engineering. * Low level systems debugging, performance measurement, and optimization on large production clusters. * Build architecture design, influence product roadmap, and take ownership and responsibility over new projects. * Introduce tools to allow greater automation and operability of services. * Use your deep experience to help prevent and investigate production issues. * Plan and lead complicated technical projects that work with several teams within the company. * Contribute as a technical team lead by mentoring others, lead sprint planning, delegating work and assignments to team members and participate in project planning. What we look for: * 15+ years industry experience building and supporting large-scale distributed systems. * Comfortable working towards a multi-year vision with incremental deliverables. * Motivated by delivering customer value and impact. * Strong foundation in algorithms and data structures and their real-world use cases. * Experience driving company initiatives towards customer satisfaction. * BS/MS/PhD in Computer Science or related majors, or equivalent experience.   About Databricks Databricks is the data and AI company. More than 10,000 organizations worldwide — including Comcast, Condé Nast, Grammarly, and over 50% of the Fortune 500 — rely on the Databricks Data Intelligence Platform to unify and democratize data, analytics and AI. Databricks is headquartered in San Francisco, with offices around the globe and was founded by the original creators of Lakehouse, Apache Spark™, Delta Lake and MLflow. To learn more, follow Databricks on Twitter, LinkedIn and Facebook. Benefits At Databricks, we strive to provide comprehensive benefits and perks that meet the needs of all of our employees. For specific details on the benefits offered in your region click here. Our Commitment to Diversity and Inclusion At Databricks, we are committed to fostering a diverse and inclusive culture where everyone can excel. We take great care to ensure that our hiring practices are inclusive and meet equal employment opportunity standards. Individuals looking for employment at Databricks are considered without regard to age, color, disability, ethnicity, family or marital status, gender identity or expression, language, national origin, physical and mental ability, political affiliation, race, religion, sexual orientation, socio-economic status, veteran status, and other protected characteristics. Compliance If access to export-controlled technology or source code is required for performance of job duties, it is within Employer's discretion whether to apply for a U.S. government license for such positions, and Employer may decline to proceed with an applicant on this basis alone.