This position is listed on behalf of a partner company, which manages all applications and next steps. Our partner is looking for a Founding Senior Software Engineer based in United Kingdom. Join a fast-growing technology startup building an AI-powered platform that transforms how organizations discover, understand, and act on information from across the digital world. As a key member of a lean engineering team, you will have the opportunity to shape the technical architecture, influence core product decisions, and drive development from concept to production. You will build scalable software systems and integrate advanced AI capabilities into real-world workflows. Your work will reach hundreds of customers quickly, giving you direct visibility into product impact and user feedback. This role offers significant ownership, technical autonomy, and the opportunity to help establish engineering foundations for long-term growth. If you enjoy solving complex challenges, moving quickly, and building impactful products in an ambitious startup environment, this opportunity is for you. Accountabilities - Architect, design, and develop core software systems, making key technical decisions across the technology stack while balancing immediate product needs with long-term scalability. - Own feature development end-to-end, from technical design and implementation to deployment, monitoring, and continuous improvement. - Integrate AI and machine learning capabilities into production workflows, including large language models (LLMs), retrieval-augmented generation (RAG) pipelines, embeddings, prompt execution, agentic systems, and fine-tuned models. - Build scalable, reliable, and maintainable systems capable of supporting significant business growth while making pragmatic infrastructure and architecture decisions. - Develop high-performance APIs, backend services, and internal interfaces that power the product, ensuring reliability, security, and a seamless customer experience.
- Design and improve data processing systems, distributed architectures, and real-time pipelines to efficiently ingest, process, and analyze large volumes of information across text, audio, and video. - Collaborate closely with the engineering team and other stakeholders to translate product requirements into effective technical solutions. - Deliver features rapidly, gather user feedback, and iterate continuously to improve product functionality and performance. - Contribute to engineering best practices, technical standards, and infrastructure decisions that support the team's continued growth. Requirements: - At least 3 years of experience building, deploying, and scaling production-grade software systems, with strong foundations in backend engineering, services, data modeling, and distributed systems. - Deep expertise in at least one technical area, combined with a willingness to expand your knowledge across the broader engineering stack. - Proficiency in one or more relevant backend technologies, such as Python, TypeScript, and PostgreSQL, with an understanding of high-concurrency systems. - Experience with cloud infrastructure, preferably AWS or GCP, as well as containerization technologies such as Docker and Kubernetes and modern CI/CD pipelines. - A strong understanding of software architecture, system reliability, performance optimization, and designing solutions that can scale with business needs. - Expertise in one or more of the following areas: - Data Engineering: Experience with Spark, Kafka, Flink, BigQuery, large-scale ETL processes, or streaming data pipelines. - Distributed Systems: Knowledge of high-volume systems, fault tolerance, scalability, and eventual consistency. - AI and Machine Learning: Hands-on experience deploying LLMs, RAG pipelines, embeddings, fine-tuned models, or optimized inference systems in production.
- £77k - £101k per annumEstimated...for Web3, led by innovations on Avalanche. The company was founded by Cornell computer scientists, who partnered with Wall Street... ...open, programmable blockchain platform. We are seeking a Senior Software Engineer with experience working with AWS-based backend services. This...SeniorFull-time
- £81k - £108k per annumEstimated...Senior Software Engineer, Backend (Identity International) Remote UK Apply At Affirm, we exist for the moments that matter—giving people a clear,... ...excited to work with someone who leaves things better than they found them, communicates clearly across audiences, uses customer...SeniorLong-term contractFull-timeRemote
- ...Who we are: Process Street is an AI software and compliance operations platform startup... ...Our culture: Process Street was founded on a strong belief in the work-life benefits... ...Opportunity We’re looking for a Senior Software Engineer to help architect and evolve Process...SeniorFull-timeSummer workRemote
- £56k - £73k per annumEstimated...drives us and how we work. The team Founded in 2011, Kraken is one of the world’s... ...and trustworthy. We’re a product-minded engineering team. Our engineers don’t just implement... ...The opportunity – We’re looking for a Senior React Native Engineer who thinks like a...SeniorFull-time
- £72k - £94k per annumEstimated...drives us and how we work. The team Founded in 2011, Kraken is one of the world’s... ...clients. We’re looking for a React Native Engineer to join our Business Services... ...contributions What you bring – 5+ years of software development experience, including hands-on...SeniorFull-time
£60k - £80k per annum
...old see the new. Java is a language that goes back as far as software engineering itself. One of the originators and still remains one of the... ...commonly used today. I am offering an opportunity for the role of Senior Java developer to come and take charge of a team of 8 mostly...SeniorRemote jobPermanent£500 - £600 per day
...Are you an experienced Senior Software Engineer with a passion for modern technologies, Agentic AI and building scalable solutions We are working with an innovative, technology-driven organisation looking for a talented Lead Software Engineer to join their engineering...Senior£70k - £80k per annum
...while enjoying substantial financial backing from the larger enterprise. This organisation is currently in search of a skilled Senior Software Engineer in Test to spearhead streamlined testing and automation strategies. In this role, you'll be a linchpin in the team, taking...SeniorRemote jobOdd jobPermanentOn-site£70k - £85k per annum
...’re looking for that role that will allow you to make a real impact. This is your opportunity to join a global leader as a Senior Software Engineer in Test and not just keep up with market growth, but lead the way while fostering a lasting cultural shift. The tech stack...SeniorRemote jobPermanentHybrid workingShift work- £69k - £90k per annumEstimated...and platform quality, enabling teams across the company to ship quickly and safely on top of Canvas Core. YOUR MISSION As a Senior Software Engineer, you’ll help design, build, and improve the Canvas platform so that the Mural editor remains reliable, high-performing, and intuitive...SeniorLong-term contractFull-timeRemote
£70k - £80k per annum
...within a tight-knit team and the robust financial support of a larger corporation. The team is on the lookout for a seasoned Senior Software Engineer to spearhead the development of scalable, reliable, and efficient software solutions. Collaborating closely with cross-...SeniorRemote jobPermanentOn-site- £60k - £78k per annumEstimated...improve those experiences. We’re a cross-functional team of engineers, product managers, designers, and data partners who move... ...quality, reliability, and scalability. YOUR MISSION As a Senior Software Engineer on the Growth & Engagement team, you’ll build the products...SeniorLong-term contractFull-time
- £54k - £72k per annumEstimated...world, Mozillians design, build and distribute open-source software that enables people to enjoy the internet on their terms. About... ...of Reviewer tools and automated moderation systems. As a Senior Software Engineer, you’ll bring a passion for crafting resilient systems that...SeniorFull-time
- £55k - £72k per annumEstimated...useful, correct at a high level, and aligned with strong engineering practice. Assess the quality of explanations,... ...explanations of evaluation feedback. Requirements Senior, staff, or principal-level software engineering experience, or equivalent experience. Strong...SeniorFull-timeRemoteFlexible hours
$100 - $200 per hour
...video for more details: We’re looking for highly experienced software engineer (SR+) to help evaluate the quality of interactions with modern... ...judgments, and explaining them clearly. WHO YOU ARE • Senior, Staff or Principal-level engineer (or equivalent experience)...SeniorFull-timeRemoteFlexible hours- £36k - £47k per annumEstimated...a tangible impact at global scale. Our Engineering culture values autonomy, excellence, ownership... ...improve how we build and operate software. If you’re excited by solving complex global... ...What you get to do: We’re looking for a Senior Software Engineer to design, build, and...SeniorFull-timeRemote
- £66k - £86k per annumEstimated...from EVs, heat pumps, and home batteries. The missing piece is software that can connect and orchestrate these devices at scale.... ...else we look at. What we're looking for: We’re hiring a Senior Backend Engineer to make Enode’s EV platform more reliable, observable, and...SeniorFull-timeOn-siteRemoteFlexible hoursShift work
- £56k - £73k per annumEstimated...operator that scaled to an eight-figure business using its own software, Base360.ai is now launching as a standalone platform for... ...their portfolios. We’re looking for a highly ambitious Senior Software Engineer who wants to build systems that solve real problems at scale...SeniorFull-timeTemporaryRemote
- £55k - £71k per annumEstimated...accounts. Our global team is a diverse group of experienced engineers, traders, and brokerage professionals who are working to... ...significant impact, we encourage you to apply. Your Role: As a Senior Software Engineer on the Clearing team you’ll work on what happens...SeniorLong-term contractFull-timeShift work
$113.08k - $175.73k per annum
...Senior Software Engineer, MediaWiki Summary The Wikimedia Foundation is looking for a Senior Software Engineer to join the MediaWiki Platform team. MediaWiki is the open-source platform that powers Wikipedia and its sister projects - impacting hundreds of millions of...SeniorPermanentFull-timeRemote- ...to cover and their potential bottlenecks Work with deployment engineers to ensure that what you build goes as quickly as possible to the... ...science or related field ~3+ years of experience as a Software Engineer (Backend) ~2+ years of experience using TypeScript ~...Senior
£85k - £105k per annum
...Running a frontline business is an operational puzzle most software has never touched. Shift-by-shift labour costs, compliance that... ...working at Sona here . About the Role We're hiring Senior Software Engineers to join our product teams and help build the next generation...SeniorRemote jobFull-timeFlexible hoursShift workRotating shifts£75k per annum
...an independent team of data & AI experts, engineers, and designers who build intelligent... ...innovative digital products. Whether you are a Senior Engineer, Tech Lead, or DevOps Engineer,... ..., CI and CD. Experience building software collaboratively using pull requests and code...SeniorPermanentFull-timeRemoteFlexible hours- £60k - £78k per annumEstimated...Summary The Wikimedia Foundation is looking for a Senior Software Engineer, iOS to join the App Growth team within the Core Experiences engineering group on a 3-month full time contract. The App Growth team has a clear and ambitious goal: make the apps the destination for...SeniorPermanentFull-timeRemote
- £43k - £56k per annumEstimated...product delivery. The Product Technology department operates across four multi-disciplinary delivery squads (engineering, design, QA, product). The Senior Software Engineer will join one squad, contributing to the design, development, and delivery of new products and...SeniorFull-timeFixed-term contractRemoteFlexible hours
€110k - €135k per annum
...About the team: Builder.io's Publish engineering team builds the platform that empowers marketing and content teams to launch pages... ...and AI-driven automation, this is the team for you. As a Senior Software Engineer at Builder.io, you will… Design and build the APIs...SeniorLong-term contractFull-timeTemporaryRemote£65k - £87k per annum
...the world, Mozillians design, build and distribute open-source software that enables people to enjoy the internet on their terms.... ...development team Mentor other team members and be mentored by more senior team members Collaborate with other teams by providing code review...SeniorFull-timeImmediate startRemote- £72k - £91k per annumEstimated...position is listed on behalf of a partner company, who manages all applications and next steps. Our partner is looking for a Senior Software Engineer – Data Search based in United Kingdom. This is a senior engineering role focused on building and improving a large-scale creator...SeniorFull-time
- £72k - £94k per annumEstimated...global team is a diverse group of experienced engineers, traders, and brokerage professionals who... ...encourage you to apply. Your Role: As a Senior Engineer, you will be responsible for... ...dedicated to delivering high-quality, seamless software solutions. The ideal candidate has a...SeniorFull-timeRemote
- £64k - £83k per annumEstimated...setting – Speechify has no office. These include frontend and backend engineers, AI research scientists, and others from Amazon, Microsoft, and... ...similar), and a dedication to building accessible and inclusive software. ~ Excellent software engineering fundamentals: OOP, design...SeniorRemote jobLong-term contractOn-site
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