32 senior backend engineer jobs found

Why voize? Because we’re more than just a job! At voize, we believe the greatest gift to frontline workers is time - time to care, connect, and be present. Today, that time is lost to admin work that pulls nurses away from what matters most: people .   Your Mission As a Freelance Senior Backend Engineer for our German Market squad , you’ll ensure that data flows smoothly between our products and our partners' software solutions. You'll build and maintain the integrations that connect the voize with senior care and hospital software platforms. We are open for you to be based remotely across Germany, France or the UK.   Your Daily Business – No two days are alike Shape the future of our integrations – Develop interfaces that seamlessly connect voize with systems in the care and medical sector Build future-proof solutions – Develop a scalable API, set industry standards, and work closely...

Why voize? Because we’re more than just a job! At voize, we believe the greatest gift to frontline workers is time - time to care, connect, and be present. Today, that time is lost to admin work that pulls nurses away from what matters most: people .   Your Mission As a Freelance Senior Backend Engineer for our German Market squad , you’ll ensure that data flows smoothly between our products and our partners' software solutions. You'll build and maintain the integrations that connect the voize with senior care and hospital software platforms. We are open for you to be based remotely across Germany, France or the UK.   Your Daily Business – No two days are alike Shape the future of our integrations – Develop interfaces that seamlessly connect voize with systems in the care and medical sector Build future-proof solutions – Develop a scalable API, set industry standards, and work closely with...

Why voize? Because we’re more than just a job! At voize, we believe the greatest gift to frontline workers is time - time to care, connect, and be present. Today, that time is lost to admin work that pulls nurses away from what matters most: people .   Your Mission As a Freelance Senior Backend Engineer for our German Market squad , you’ll ensure that data flows smoothly between our products and our partners' software solutions. You'll build and maintain the integrations that connect the voize with senior care and hospital software platforms. We are open for you to be based remotely across Germany, France or the UK.   Your Daily Business – No two days are alike Shape the future of our integrations – Develop interfaces that seamlessly connect voize with systems in the care and medical sector Build future-proof solutions – Develop a scalable API, set industry standards, and work closely...

Why voize? Because we’re more than just a job! At voize, we believe the greatest gift to frontline workers is time - time to care, connect, and be present. Today, that time is lost to admin work that pulls nurses away from what matters most: people .   Your Mission As a Freelance Senior Backend Engineer for our German Market squad , you’ll ensure that data flows smoothly between our products and our partners' software solutions. You'll build and maintain the integrations that connect the voize with senior care and hospital software platforms. We are open for you to be based remotely across Germany, France or the UK.   Your Daily Business – No two days are alike Shape the future of our integrations – Develop interfaces that seamlessly connect voize with systems in the care and medical sector Build future-proof solutions – Develop a scalable API, set industry standards, and work closely with...

OVERVIEW Senior Agentic AI Engineer / AI Architect - multi-agent AI systems London (4 Days Onsite) 6 month Contract (Inside IR35)   UST is seeking a Senior Agentic AI Engineer / Architect to design, build, and deploy enterprise-scale AI solutions powered by LLMs, Agentic AI, and Multi-Agent Systems. This is a hands-on role for someone who has moved beyond PoCs and has successfully delivered production-grade AI applications at scale. You'll work closely with architects, engineers, and business stakeholders to solve complex challenges using the latest AI technologies.   What You'll Do Design and develop multi-agent AI systems using modern orchestration frameworks. Build intelligent workflows leveraging agent planning, reasoning, memory, tool usage, and task delegation. Deliver production-ready solutions using LLMs, RAG, and AI-powered automation. Develop secure, scalable Python services, APIs, and orchestration layers....

Senior Platform Engineer - Contract - Outside IR35 Full job description We’re looking for an EPOS & SCO Platform Engineer to build, configure, and support the in-store point of sale and self-checkout platforms across the estate. You’ll own the full lifecycle of Travel Money Kiosks, EPOS and Hospitality infrastructure, including till hardware, self-checkout units, peripherals, and backend systems—ensuring services are secure, compliant, resilient, and consistently deployed at scale. You’ll automate provisioning, configuration, updates, and monitoring so stores benefit from reliable transaction processing, seamless customer journeys, and minimal downtime. Success means stable retail operations, predictable performance, and confidence from store colleagues, product owners, and operations teams. This is a hybrid role where 3 days per week are expected on site in Bracknell. Requirements Role Responsibilities: Design,...

Role description Senior Agentic AI Engineer / AI Architect - multi-agent AI systems London (4 Days Onsite) 6 month Contract (Inside IR35)     UST is seeking a Senior Agentic AI Engineer / Architect to design, build, and deploy enterprise-scale AI solutions powered by LLMs, Agentic AI, and Multi-Agent Systems. This is a hands-on role for someone who has moved beyond PoCs and has successfully delivered production-grade AI applications at scale. You'll work closely with architects, engineers, and business stakeholders to solve complex challenges using the latest AI technologies.     What You'll Do Design and develop multi-agent AI systems using modern orchestration frameworks. Build intelligent workflows leveraging agent planning, reasoning, memory, tool usage, and task delegation. Deliver production-ready solutions using LLMs, RAG, and AI-powered automation. Develop secure, scalable Python services, APIs, and...

Senior Platform Engineer - Contract - Outside IR35 Full job description We’re looking for an EPOS & SCO Platform Engineer to build, configure, and support the in-store point of sale and self-checkout platforms across the estate. You’ll own the full lifecycle of Travel Money Kiosks, EPOS and Hospitality infrastructure, including till hardware, self-checkout units, peripherals, and backend systems—ensuring services are secure, compliant, resilient, and consistently deployed at scale. You’ll automate provisioning, configuration, updates, and monitoring so stores benefit from reliable transaction processing, seamless customer journeys, and minimal downtime. Success means stable retail operations, predictable performance, and confidence from store colleagues, product owners, and operations teams. This is a hybrid role where 3 days per week are expected on site in Bracknell. Requirements Role Responsibilities: Design,...

Must have skills: Demonstrable experience with Solidity. Strong understanding of blockchain security practices and potential vulnerabilities. Proficiency in Hardhat and Foundry. Experience with Solidity security testing tools like Slither, Mythril, Echidna Practical experience with scripting languages like Javascript or Typescript. Ability to craft unit, integration, fork, and invariant tests, ensuring code longevity. Demonstrable aptitude for best development practices, data structures, algorithms, and methodologies. Bachelor's degree in Computer Science, Engineering, or a related STEM discipline. Excellent debugging and troubleshooting skills. Strong written and verbal communication skills. Self-motivated with the ability to work in a fast-paced, evolving environment. Proficient communication skills in English. Development background in sectors such as banking, finance, or trading, paired with a comprehensive grasp of financial...

Senior Product Engineer (Freelance) Full job description 3-4 days per week, hybrid work policy in central London office We're looking for a freelance product engineer to join us between June and October 2026, working primarily on wonderbly.com with a focus on driving growth into Q4. This is a hands-on role. The work involves close collaboration with the VP product and other teams to solve deep customer experience challenges around our Kids and Keepsake landing pages and journeys, in order to unlock growth in these key areas for the business. You'll be working within a small, focused team — and at least some of the time, with a fair amount of autonomy. We're not looking for someone to execute a perfect brief. We're looking for someone with the judgment to help us figure out the right thing to build, and then build it well. A few things that are important to us The work you're doing feeds directly into beautifully made, deeply personal books...

Joining a new project Ideally have worked on Financial Services Projects before (Payments would be great) Fullstack Experience Tech Stack - Kotlin Backend, JS/TS React Frontend Start date ASAP Duration 6 months (Likely to extend) 2/3 days / week in person working (London) Immediate Interviews   The best bit about Red Badger is, of course, the team. We are really proud of our people; we support and learn a lot from each other; we work really hard but have fun doing it. We are a diverse group made up of 22 different nationalities, speaking 17 different languages.   Our 3 founders, Dave, Cain and Stu, who have considerable tech and consultancy experience and still own 100% of the company. We've been consistently profitable and have grown responsibly from the beginning.   We are based at Old Street in the heart of "tech city" and get thoroughly stuck in with the brilliant community around us. We run...

Location: London 1-2 days a week. Department: Engineering Employment Type: Contract Contract Length: 6 months (with potential for extension) About YLD: Our goal is to help our clients keep moving forward. We work with them to build the skills and capabilities they need to stay ahead of the competition, and we know our success only happens when they succeed. We’re a team of curious, talented people, and we’re committed to making YLD a place where great people want to work, grow, and stay. We’re a remote-first consultancy specialising in software engineering, product design, and data. Our teams are based across London, Lisbon, and Porto, and we create digital solutions that continue to deliver value long after our work is done. About the role: As a Senior Software Engineer at YLD, you’ll be part of a client team building innovative products. We’re looking for someone curious, passionate, driven, and...

Senior Platform Engineer - Contract - Outside IR35 We’re looking for an EPOS & SCO Platform Engineer to build, configure, and support the in-store point of sale and self-checkout platforms across the estate. You’ll own the full lifecycle of Travel Money Kiosks, EPOS and Hospitality infrastructure, including till hardware, self-checkout units, peripherals, and backend systems—ensuring services are secure, compliant, resilient, and consistently deployed at scale. You’ll automate provisioning, configuration, updates, and monitoring so stores benefit from reliable transaction processing, seamless customer journeys, and minimal downtime. Success means stable retail operations, predictable performance, and confidence from store colleagues, product owners, and operations teams. This is a hybrid role where 3 days per week are expected on site in Bracknell. Requirements Role Responsibilities: Design, build, and maintain EPOS and SCO...

Senior Platform Engineer - Contract - Outside IR35 We’re looking for an EPOS & SCO Platform Engineer to build, configure, and support the in-store point of sale and self-checkout platforms across the estate. You’ll own the full lifecycle of Travel Money Kiosks, EPOS and Hospitality infrastructure, including till hardware, self-checkout units, peripherals, and backend systems—ensuring services are secure, compliant, resilient, and consistently deployed at scale. You’ll automate provisioning, configuration, updates, and monitoring so stores benefit from reliable transaction processing, seamless customer journeys, and minimal downtime. Success means stable retail operations, predictable performance, and confidence from store colleagues, product owners, and operations teams. This is a hybrid role where 3 days per week are expected on site in Bracknell. Requirements Role Responsibilities: Design, build, and maintain EPOS and...

Must have skills: Demonstrable experience with Solidity. Strong understanding of blockchain security practices and potential vulnerabilities. Proficiency in Hardhat and Foundry. Experience with Solidity security testing tools like Slither, Mythril, Echidna Practical experience with scripting languages like Javascript or Typescript. Ability to craft unit, integration, fork, and invariant tests, ensuring code longevity. Demonstrable aptitude for best development practices, data structures, algorithms, and methodologies. Bachelor's degree in Computer Science, Engineering, or a related STEM discipline. Excellent debugging and troubleshooting skills. Strong written and verbal communication skills. Self-motivated with the ability to work in a fast-paced, evolving environment. Proficient communication skills in English. Development background in sectors such as banking, finance, or trading, paired with a comprehensive grasp of financial...

We are seeking a Backend Java Software Engineer to join our team on a contractual basis. This role heavily focuses on Java, Backend, iGaming Operator Integrations.   This is 1 year extendable contract and applicants must operate through a fully registered limited company to be considered for this role. The role is fully remote, with occasional travel required to our headquarters in Málaga, Spain   What You’ll Do Design, develop and maintain scalable, resilient backend services using Java (17+) and Spring Boot, with a strong focus on quality and a zero-defect mindset. Build and evolve integrations between our iGaming platform and operators, aggregators and other external partners. Design and implement robust REST APIs, asynchronous integrations and event-driven services supporting high-volume, real-time gaming transactions. Develop and maintain common platform capabilities supporting operator integration,...

Senior Product Engineer (Freelance) Full job description 3-4 days per week, hybrid work policy in central London office We're looking for a freelance product engineer to join us between June and October 2026, working primarily on wonderbly.com with a focus on driving growth into Q4. This is a hands-on role. The work involves close collaboration with the VP product and other teams to solve deep customer experience challenges around our Kids and Keepsake landing pages and journeys, in order to unlock growth in these key areas for the business. You'll be working within a small, focused team — and at least some of the time, with a fair amount of autonomy. We're not looking for someone to execute a perfect brief. We're looking for someone with the judgment to help us figure out the right thing to build, and then build it well. A few things that are important to us The work you're doing feeds directly into beautifully made, deeply personal books...

We are looking for a Senior Fullstack Mobile Engineer with a strong emphasis on backend architecture to join the team developing a greenfield platform. You will own the end-to-end technical delivery of features, with the majority of your time focused on designing and building a robust, secure, and scalable backend using NestJS, Node.js and TypeScript . On the mobile side, you will contribute to feature integration and deployment within a React Native and Expo environment, ensuring seamless delivery across the full technology stack. The platform operates within a large enterprise technology ecosystem, so this role requires a senior engineer who is comfortable driving technical discussions, making architectural decisions, aligning infrastructure, and collaborating with neighbouring teams working across different technology stacks, including Kotlin and Spring Boot .   This role requires onsite time in Pimlico and sits inside IR35.   Backend...

Senior QA Engineer (Contract) – USA Tech Team     Contract Details Contract Length: Initial 12-month contract IR35 Status: Outside IR35 Location: Hybrid / Remote (UK)   This is an opportunity to join Nando's USA Technology team on a long-term contract, helping build and scale the digital products that support our expansion across the USA. You'll help ensure quality is built into every stage of delivery, working alongside engineers, Product Managers and Designers to deliver reliable, high-performing digital experiences within a collaborative, agile environment.     Overall Ambition Help deliver exceptional digital experiences for Nando's customers across the USA by embedding quality throughout every stage of software delivery. You'll join a fast-moving engineering team, ensuring quality is considered from discovery through to production by combining thoughtful test strategy, intelligent automation...

Skills & Experience Job roles: AI Engineer Experience level: Mid, Senior Core skills considered: Artificial Intelligence, Python, APIs, Cloud Computing, Docker Other skills considered: Kubernetes, Terraform, CI/CD, Data Pipelines Logistics Base salary: Undisclosed Employment type: Freelance/Contract Remote working: Remote Work from: Within Europe Visa sponsorship: Not available Job Description You 9ll design, build, and integrate advanced AI models into real software systems. This role sits at the intersection of software engineering, data science, and MLOps, turning research into robust, scalable, production-ready AI services. Core Responsibilities Model Engineering Build functional AI services from architectural designs Orchestrate data ingestion, inference flows, and output pipelines Optimise...