Client Server Ltd.

London, Greater London £100k - £120k per year Senior Python Developer / Software Engineer London / WFH to £120k Join a growing, global, Fintech services company that has seen 30-40% year on year growth for the past 10 years and has ambitious growth plans. As a Senior Python Developer you'll join a high performance engineering team building the next generation of data-intensive financial platforms, you'll take ownership of Greenfield services and platform capabilities, designing and delivering scalable backend systems from concept through to production. This is an opportunity to work on long-term, technically challenging projects involving large scale data processing, event-driven microservices and cloud-native architecture where you can take ownership and make an impact. Location / WFH: You'll join the team in Central London three days a week with flexibility to work from home the other two days. About you: You have strong Python development skills including FastAPI (will also consider Django or Flask experience) You have experience of working on event driven microservices with large scale data You're keen to take ownership and work across the full software development lifecycle on Greenfield projects (introducing new features and enhancements) You have a good understanding of financial services, FX experience preferred but not essential You enjoy problem solving and working on complex systems You're collaborative with great communication skills You're degree educated, having achieved a 2.1 or above in a STEM discipline from a top tier university What's in it for you: Salary to £120k Private Medical Healthcare including Dental and Vision cover Pension Employee Wellness Programme Summer time hours £2k personalised training budget At Client Server we believe in a diverse workplace that allows people to play to their strengths and continually learn. We're an equal opportunities employer whose people come from all walks of life and will never discriminate based on race, colour, religion, sex, gender identity or expression, sexual orientation, national origin, genetics, disability, age, or veteran status. The clients we work with share our values.

Client Server Ltd. is seeking a Senior Python Developer to join their growing team in London. You will be responsible for developing data-intensive financial platforms and taking ownership of Greenfield projects, delivering scalable backend systems. The role offers a salary up to £120k, private medical healthcare, a pension plan, and a £2k training budget. You'll work in a collaborative environment that values diversity and continuous learning.

Client Server Ltd. is hiring a Platform Engineer for their London office with a competitive salary of up to £100k. This hands-on role supports a high-frequency trading environment specializing in crypto markets. You will be part of a small team focused on enhancing the web scraping function, with key responsibilities in process improvement and collaboration with development and infrastructure teams. The ideal candidate should possess strong scripting skills in Bash, Python, and a solid understanding of AWS and Linux.

London, Greater London £85k - £100k per year Platform Engineer (AWS Linux Python Cloud) London / WFH to £100k Opportunity to progress your career at a hugely profitable High Frequency Trading firm that specialise in crypto markets, in a hands on Platform Engineer role. As a Platform Engineer you will join a small team responsible for the 24x7x365 globally distributed ethical web scraping function, supporting a multi-region high frequency operation. You'll proactively identify, analyse, drive and own performance and process improvements, collaborating closely with the development team on architecture and prioritisation and with the infrastructure team on common infrastructure improvements across the estate. Location / WFH: You'll join the team in Central London with flexibility to work from home once a week. About you: You have commercial experience as a Platform Engineer, DevOps Engineer or SRE within an finance / FinTech environment You have strong bash, Python, C# or Rust scripting / coding skills You have strong AWS cloud experience You have a strong knowledge of Linux You're collaborative and pragmatic with great communication skills You hold a technical degree, Computer Science preferred - 2.1 or above from a top tier university Ideally you will also have some experience with one of the following: Containerisation (Docker / Kubernetes), monitoring tools (Prometheus / Grafana / ELK stack / Splunk), IaC tooling (Terraform, Ansible etc.) What's in it for you: As a Platform Engineer you will receive a competitive package: Salary to £100k Pension

Client Server Ltd. is seeking a skilled Data Engineer (Python ETL AWS SaaS) to join their expanding team in the UK. This role offers the chance to work with real-time data and modern technologies, playing a crucial role in an innovative car insurance tech company. You will enjoy flexible working arrangements and a comprehensive benefits package, including a competitive salary up to £95k, enhanced maternity leave, and various wellness perks.

Senior Deep Learning Engineer - Quant Trading London, Greater London £120k - £150k per year Senior Deep Learning Engineer (Python TensorFlow Lattice) London to £150k+ Do you have expertise with Deep Learning within commercial environments? You could be joining a specialist Hedge Fund and working on long term strategic projects which involve implementing quantitative statistical models that are used to forecast elements of demand and supply of energy for European markets. What's in it for you Up to £150k + bonus Private Medical Insurance Life Assurance Training and career development opportunities Employee Assistance Programme Company retreats such as Winter skiing trips and Summer weekends away Your role As a Senior Deep Learning Engineer you will design, develop and deploy advanced deep learning models to tackle some of the most complex problems in global energy markets, applying cutting edge neural network and deep learning techniques across diverse and challenging data sets. You'll combine deep technical expertise in neural networks and deep learning with practical experience delivering models end to end, from research to production, in a high performance environment. Your work will directly impact trading decisions, turning sophisticated models into actionable insights. Location You'll be working in a collegiate team environment based in North London with a small group of accomplished software / data engineers and finance entrepreneurs. About you As a Senior Deep Learning Engineer you will receive a competitive package: You have an excellent academic record of achievement; 2.1 or above in a quantitative discipline at BSc, from a Russel Group university You have strong hands on experience building and shipping deep learning models in production, including ownership of end to end pipelines You have strong Python skills You have experience with deep learning tools such as TensorFlow Lattice (TFL), OptNet, DeepXDE You have a strong understanding of statistics and Machine Learning fundamentals You have experience of working with large, messy datasets You're collaborative with great communication skills At Client Server we believe in a diverse workplace that allows people to play to their strengths and continually learn. We're an equal opportunities employer whose people come from all walks of life and will never discriminate based on race, colour, religion, sex, gender identity or expression, sexual orientation, national origin, genetics, disability, age, or veteran status. The clients we work with share our values.

Client Server Ltd. is seeking a Front End Developer React to create data-centric user interfaces for Geospatial data. This role is based in the picturesque Cotswolds, part of a small team at a tech start-up. You will be responsible for creating interfaces that monitor artic ice flows and collaborate on impactful projects. The ideal candidate possesses strong knowledge of Geospatial data, CompSci fundamentals, and experience in a start-up environment. The company offers a salary up to £85k, equity, and opportunities for professional growth as they scale.

Client Server Ltd. is seeking a Principal Software Engineer to lead technical transformations and mentor engineering teams. This role offers a competitive salary of up to £110k, alongside numerous benefits including 25 days holiday and an onsite gym. Located in London, the position allows for a hybrid work model, combining office presence with the flexibility of working from home. Join a renowned financial services company dedicated to helping individuals manage their debt in a rapidly evolving tech landscape.

Client Server Ltd. is seeking a Senior Software Developer / Engineer (C# .Net Azure API) in London. This role involves contributing to a tech incubator within a global health company during a period of transformation. As a key player, you'll design and develop backend services, improve code quality, and collaborate with cross-functional teams. The position offers a salary of up to £90k, with options for hybrid working, allowing flexibility between the office and home. In return, you'll enjoy benefits including 26 days holiday, a pension plan, and private health and dental insurance.

London, Greater London £100k - £130k per year Senior Front End Engineer / Developer (TypeScript React) London / WFH to £130k Are you a Front End technologist who enjoys building systems from scratch? You could be progressing your career, in a senior, impactful role at a global, prime broker that is replacing the legacy infrastructure used across capital markets with a new cloud-native clearing and custody system, designed for today's complex global markets. The company is experiencing great success in the US and is expanding into the UK. As a Senior Front End Engineer you will take ownership of building the front end UI for a brand new Futures Trading platform for the UK, primarily using TypeScript and React. You'll be working on complex and challenging, highly available mission critical systems in collaboration with Product Managers to understand and define new features and coordinating with other developers with the goal of writing software as one. You'll be empowered to implement the latest tech, seeking continual improvement and can build a team around you, progressing to a leadership role. Location / WFH: You'll join a small, highly talented and collaborative team in the London, City office three days a week with flexibility to work from home the other two. About you: You have experience within a big tech, eCommerce or other high web traffic environment You have strong front end development skills with TypeScript and React experience, building scalable web applications You take in pride in producing clean, high quality, well tested code You have experience of working on Greenfield systems and creating front end web applications from scratch You're familiar with modern software engineering practices You are collaborative and pragmatic, able to take ownership and work with others You have experience across the full development lifecycle You are degree educated in Computer Science or closely related discipline What's in it for you: As a Senior Front End Engineer / Developer you receive a competitive package: Salary to £130k Pension Influential role at a growing company with excellent career progression and interesting work Apply now to find out more about this Senior Front End Engineer / Developer (TypeScript React) opportunity. At Client Server we believe in a diverse workplace that allows people to play to their strengths and continually learn. We're an equal opportunities employer whose people come from all walks of life and will never discriminate based on race, colour, religion, sex, gender identity or expression, sexual orientation, national origin, genetics, disability, age, or veteran status. The clients we work with share our values.

Client Server Ltd. is seeking a Backend Software Engineer to join their team in London. This role involves designing and developing low-latency backend systems and APIs in C# .Net, working on innovative greenfield trading projects, and collaborating with diverse teams. The ideal candidate has extensive experience in C# .Net and SQL, with strong communication skills. The position offers a competitive salary up to £90k, along with a biannual bonus and opportunities for professional development.

Client Server Ltd. is seeking a Technical Program Manager - Infrastructure in London, offering a salary of up to £90,000 annually. The role will require you to lead and facilitate delivery across complex infrastructure and platform projects. Join a supportive team within a growing European car insurance tech company, where you'll collaborate closely with engineering leaders and manage stakeholder communications effectively. Flexible working options are available, with a hybrid model preferred.

Client Server Ltd. is seeking a Software Engineer / Developer to join their Newcastle team. In this role, you'll work on exciting systems, join a talented team, and produce high-quality code in C# .Net. This FinTech start-up offers a salary up to £70k, bonuses, and great working conditions in a vibrant team atmosphere. Expect opportunities for career growth as the company expands. Ideal candidates will have a strong technical background and be excited to shape this role.

Client Server Ltd. is seeking a Software Developer / Engineer (Backend Elixir AI) to join their team in London. This position offers a competitive salary of up to £130k, allowing for flexible working with 1-2 days weekly at the London office. You will work on innovative Large Language Model products that transform financial services and improve operational efficiency. Ideal candidates have a passion for functional programming and technology in a fast-paced, inclusive environment.

London, Greater London £80k - £90k per year Senior Software Developer / Engineer (C# .Net Azure API) London / WFH to £90k Do you have strong C# and Azure skills combined with a strong knowledge of software engineering best practices? You could be progressing your career in a senior, hands on Senior Software Developer role at a hugely successful, global health / wellness company as they go through a period of technical transformation. What's in it for you: Salary to £90k 26 days holiday Pension Private Health and Dental Insurance Access to a wide range of financial services Your role: As a Senior Software Developer you'll join a team acting as a "tech incubator" within the wider business who are enabling the business to transform from fitness through to a lifestyle and wellbeing experience, via the customer facing member engagement platform. You'll design, develop, build and evolve the backend and integration services powering the digital ecosystem and related platforms, delivering reliable, secure and scalable software across internal and third party systems. As a senior member of the team you'll take ownership of projects, collaborating with Engineering Leads, Product Managers and Front End Engineers to deliver high quality backend services, improve code quality and drive best practices. Location / WFH: You'll join a friendly, diverse team based in the London office three days a week with flexibility to work from home twice a week in a hybrid model. About you: You have strong C# .Net backend development experience You have strong Azure experience in production environments You have strong REST API and integration experience You have a good understanding of event driven systems and asynchronous programming You're proficient with CI/CD pipelines, automated testing, monitoring, modern software development best practices You have a strong grounding in Computer Science, with a BSc degree You're collaborative with great communication skills Ideally you will have an interest in health and wellbeing Apply now to find out more about this Senior Software Developer / Engineer (C# .Net Azure API) opportunity.

Technical Program Manager - Infrastructure London, Greater London £80k - £90k per year Technical Program Manager (Infrastructure) Remote UK to £90k Are you a tech savvy Program Manager with a good knowledge of Infrastructure / Platform engineering? You could be progressing your career as part of a friendly and supportive international team at a growing and hugely successful European car insurance tech company as they expand their UK presence; their platform enables an insurance quote to be made to the consumer within 60 seconds, using just 4 clicks. What's in it for you: Up to £90,000 salary Ability to work 30 days from any EU country Diverse, inclusive team environment with a range of support networks (e.g. LGBTIQA+, Women's Networking group) Your role: As a Technical Program Manager you'll focus on facilitating and driving delivery of infrastructure and platform projects, leading the delivery of complex infrastructure and platform programs, coordinating cross functional engineering teams to ensure initiatives are planned, prioritised and executed successfully. You'll be collaborating with engineering leaders and architects, managing dependencies, risks, resources and stakeholder communications, providing clear reporting and visibility into program health and delivery progress. You will enable Agile planning and continuous improvement activities, using delivery metrics and tooling insights to optimise execution and establish scalable delivery practices. The role also includes organising technical workshops and team events, as well as managing relationships with infrastructure and technology vendors, overseeing commercial negotiations, compliance requirements, and budget planning in partnership with Security, Legal, Procurement and Engineering teams. About you: You have strong commercial experience in Technical Program Management, Infrastructure Program Management, or Technical Project Management roles You have a strong understanding of infrastructure and platform engineering environments You have experience of managing complex cross-functional technical programs and dependencies You have a good understanding of Agile delivery methodologies and engineering execution practices You have experience with project management tools such as YouTrack, Jira, and Confluence You have advanced stakeholder management and business relationship skills Location / WFH: The company is a big advocate of flexible working and prides itself on DEI; ideally you'll be able to get to the London office twice a week.

Backend Software Engineer C# .Net SQL - Sports Trading London, Greater London £75k - £90k per year Backend Software Engineer (C# .Net SQL) London / WFH to £90k Join a global sports trading firm as a Backend Software Engineer, building real-time, high-performance trading systems with clear business impact. What you'll do: Design and develop low-latency backend systems and APIs in C# .Net Work on greenfield trading projects alongside strategy teams Contribute to scalable, high-performance systems with real-time data Collaborate across engineering teams and business stakeholders About You: You have strong C# .Net / ASP.Net backend experience You have a good knowledge of SQL or Oracle databases You have a solid understanding of Computer Science fundamentals (OOP, Data Structures, Design Patterns, Algorithms) You have strong communication and teamwork skills What's in it for you: Salary up to £90k 10-25% bonus paid biannually Professional development and social perks At Client Server we believe in a diverse workplace that allows people to play to their strengths and continually learn. We're an equal opportunities employer whose people come from all walks of life and will never discriminate based on race, colour, religion, sex, gender identity or expression, sexual orientation, national origin, genetics, disability, age, or veteran status. The clients we work with share our values.

Client Server Ltd. is seeking a Junior Backend Software Engineer in London to design and develop backend services using Rust for high-frequency trading systems. You will be joining a talented team where you can learn and grow your skills in a dynamic environment. This position offers a salary between £70k and £90k per year, with flexible working options, including the ability to work from home twice a week. Ideal candidates will have a degree from a top-tier university and experience in backend development.

Client Server Ltd. is looking for a Backend Software Engineer/Developer in London to work in a senior, hands-on role within the health and wellness sector. You will design and evolve backend services, ensuring secure and scalable solutions across various systems. The ideal candidate has strong C# .Net development and Azure experience and understands APIs and integration systems. This position offers a salary up to £75k, 26 days holiday, and flexible WFH options.

Front End Developer React - Geospatial Data Do you have experience of visualising Geospatial data? You could be working on complex and interesting systems related to Polar Exploration in a beautiful Cotswolds based office, as part of a small team at a tech start-up, where you can make an impact and progress your career. As a Front End Developer you will design and develop Greenfield, data centric user interfaces that monitor artic ice flows and various other data points for clients within governments, defence, energy exploration and conservation. You'll focus on front end development, taking ownership of projects and working end-to-end from ideation through to production of new features and applications. Location: You'll be based in a beautiful Cotswolds (near Cirencester) office, with stunning views and a range of facilities including free parking onsite (not commutable on public transport). About you: You have a good understanding of Geospatial data and data visualisation You're comfortable using AI tools such as Claude in your everyday workflow You have experience in a start-up or small business, keen to work on Greenfield projects with ownership You have a strong knowledge of CompSci fundamentals such as OOP, Data Structures, Design Patterns You're collaborative with great communication skills, happy to partake in technical discussions and decision making You're degree educated in a STEM discipline What's in it for you: Salary to £85k Equity Impactful role with great career progression as the company scales