Backend 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. What you'll work on * This role is the opportunity to take on the technical leadership on projects, defining and designing systems, making quick proof of concepts and working closely with Product and our Clients. * Write code and lead others in the team in delivering new service functionality, implementing API’s, data routing/processing and automation mechanisms. * Development and engineering primarily on the backend services and web application hosted tools and systems of the 9fin platform. * Taking a leading role within project teams as an IC, running code reviews and mentoring of junior developers, involvement in early research and experimentation with new technologies providing input for new features and products. * Continually improve on the 9fin codebase taking the chance to automate, refactor and document when you can. * Variety: Our web platforms are incredibly diverse, from complex financial data modelling, capturing environmental, emission, energy data, incorporation of ML/AI prediction services, data visualisation serving and automation systems. * Collaboration and teamwork: Cross functional teams are formed for all projects including the appropriate domain expertise from 9fin financial, legal and editorial colleagues. This allows the best quality information and feedback to go directly to engineering project teams. Your ability to explain and break down complex projects to non technical audiences will enable productive and efficient team progress. * Developer Experience: Through managed automated preview environments, feature flags and well maintained non production environments. You will be able to move with velocity and get feedback and iterate quickly. Our Backend Stack * Python is the dominant backend language used * Flask&FastAPI * Typing is used within our Python stack to power automated documentation and API definitions * Relational Databases (PostgreSQL) at the heart of majority of services * We’re AWS for Cloud hosted services * Heavy use of AWS lambda Serverless * Docker (AWS ECS) for uniform development/deployment from dev to prod Requirements This role will be a great fit if you: * Can effectively plan and reason about your software, understanding where it fits into systems and the overall business * Can think about how data will pass through your software; from persistent storage through to API endpoint * Experience with Python and its web frameworks (we currently use Flask, and are moving to FastAPI with Typing) * Strong experience delivering APIs, Service Oriented Architecture * Good working knowledge of SQL statements for retrieving data * A good collaborator and communicator with cross functional engineering teammates and others within 9fin * Code Quality: Through writing testable, maintainable code, and by engaging in code review for your own work and for reviewing others 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.

Conduct

TL;DR: We're looking for exceptional builders who help us design and ship the foundational infrastructure that lets Conduct scale to the world's largest enterprises, while accelerating the product teams building on top of it. WHY CONDUCT The world's largest companies are slowed down by the software they run on. We’re building the AI operating system that absorbs IT complexity and unlocks entirely new levels of speed, output, and ambition. We believe this is a generation-defining mission. Major enterprises already trust us with their most critical systems, we just closed a $60M Series A from top-tier funds, and we're still early enough that what you build here defines the company. We're a small, talent-dense team doing our life's work at Conduct - we value extreme ownership, high velocity, and low-ego collaboration. If you bring that same drive, we will make sure this is the place you do yours too.   WHO WE HIRE We're looking for pragmatic, high-agency engineers who thrive in ambiguity and care as much about the system as the feature. Fundamentals matter more to us than familiarity with any specific tool. If you're strong, you'll pick it up fast. You'll stand out if you: * Have 3+ years of backend experience with exposure to platform or infrastructure work. You have seen what it actually takes to go from MVP to scalable, production-grade systems * Have strong system design instincts and own problems end-to-end across APIs, infrastructure, and data flows * Are experienced with distributed systems, scaling databases (postgres), queueing, and large-scale batch processing * Understand how to benchmark and tune systems under real load, and know how to make pragmatic trade-offs when the data is ambiguous * Are familiar with LLM infrastructure at scale * Raise the bar around you — through code, mentorship, and better systems — and fix problems without waiting for permission   WHAT YOU’LL OWN You'll have broad ownership across architecture, developer experience and production systems. The infrastructure problems are real and genuinely hard: we process tens of millions of lines of code per customer, generating large-scale LLM workloads under enterprise-grade reliability requirements. You'll work on the systems that keep product teams fast and unblocked and that hold up as we onboard some of the largest companies in the world. In practice that means: * Accelerating product teams. You build the platform that lets engineers focus on product, not plumbing: shared abstractions, sensible defaults, internal tooling that compounds. * Scaling with confidence. You design and maintain infrastructure that meets stringent enterprise reliability requirements and doesn't become fragile as we grow. * Taming LLM infrastructure. High token throughput, real-time usage, flaky providers — you make it reliable. * Raising the floor, not just the ceiling. From auth to observability to job orchestration, you build systems that are well-designed from the start and don't need to be rebuilt later.   OUR STACK Our stack prioritises what matters: shipping to customers—fast—without compromising on quality and engineering. Fundamentals are more important to us than familiarity with any technology or tool: if you're strong, we’re sure you'll pick it up fast. Here’s our setup: * React, Vite, TanStack frontend * Kotlin backend: Modern and expressive, paired with the maturity, tooling, and depth of the Java ecosystem. Lets us ship fast now without painting ourselves into a corner later. * Temporal and PortKey: Absorbs infrastructure complexity around durable execution and enterprise-compliant LLM routing, so we can focus on shipping instead. * Specialised LLM Harness: Built from hard-earned experience to give agents maximum freedom and intelligence without compromising on enterprise control, governance, or reliability.

heycar

Since August 2019, we’ve been making it easier for customers to find the right vehicle, and for automotive retailers to sell them.  More recently, we’ve been on a journey… In June 2025 we were acquired by Volkswagen Financial Services UK (VWFS UK) and our mission is simple: build the right tech solutions for Volkswagen Group UK and its retailers, so they can deliver the best possible experiences to their customers.  We’re a mix of problem-solvers, innovators, and team players who care about doing great work and making a difference. We thrive on collaboration, innovation, and a shared commitment to excellence. We deliver impactful solutions at pace that put the customer at the centre.  If you're looking for a meaningful challenge, and want to help shape the future of automotive experiences, then read on…   About the role :  Join the team and play a pivotal role in building highly scalable and maintainable backend services. You'll have the opportunity to leverage and suggest the latest tools and techniques, collaborating closely with Product, Design, and Sales teams. We encourage sharing technical solutions and product ideas through code and design reviews, pair programming, and presentations, all while continuously improving our Agile processes.   What you’ll do: Our culture empowers our talented developers to develop using whichever tools we need to get the job done. To face the many challenges, including brilliant customer experience, data processing,  microservice architecture and more. * Hands on building highly scalable and maintainable backend services. * Use appropriate tools for development and being proactive in suggesting new tools, frameworks or techniques * Collaborate across functional teams including Product, Design and Sales * Share technical solutions and product ideas through code and design reviews, pair programming, and presentations * Highlight areas we can improve on as a team practising Agile processes   Our Tech Stack: We use the tools we need to get the job done. We primarily use the following tools and frameworks (some have been added in the past year, and more are planned): Python Django FastAPI AWS ElasticSearch Postgresql Kafka Github Kubernetes     What you’ll need: * Strong technical skills to build scalable backend services, primarily in Python (in any framework) * Analytical skills: a love for problem solving, and improving our working processes.  We are always learning * A good understanding of databases, OO design, data structures and SOLID principles * Strong desire to work collaboratively with both your peers and business teams * The ability to communicate technical concepts to other members of the team.   What we’ll give you: * Compensation: We offer a competitive salary + performance based bonus * Holidays: We want you to relax, you’ll have 28 days off (plus bank holidays) throughout the year. We also give you an extra day off to enjoy your birthday! * Benefits + Perks: With private medical insurance, learning and development opportunities and mental health support we’ll give you the extra boost. * Hybrid Working: We have a flexible working culture here at heycar. With hybrid working in our offices in Holborn (London) and working from home days. * Feedback: You'll be joining more than just another scale up - our team are at the heart of everything we do; here we don’t leave things unsaid, we encourage honest feedback. * A Challenge: Fast paced but not fraught. So we need you to keep up, push back and question where you see fit. * Fun: We provide a fully stocked kitchen and bar, an awesome office environment and epic socials.   If you’re ready to work with a creative, high-performing group of people we want to hear from you. Please apply directly to this role. Contact : Reece Jagger for more details.