1 to 25 of 352 Permanent Open Source Jobs in London

leading global organisations — constantly pushing boundaries and finding smarter ways to deliver value. Innovation is at the heart of everything this team does. They explore the latest cloud platforms, open-source tools, and modern technologies to create solutions that are as inspiring as they are effective. You'll join a thriving community of specialists who take pride in … ensuring best practices and high standards throughout delivery. Contributing to proposals and client engagements, helping to define innovative and competitive solutions. Staying hands-on with modern cloud-native and open-source technologies, continually learning and exploring new ideas. This is an opportunity to influence outcomes at every level — guiding technology choices and shaping solutions that make a lasting … clearly, and enjoy seeing your designs come to life. Our client is looking for someone with: Strong, hands-on experience with AWS and building cloud-native solutions. Expertise in open-source frameworks , API-led design , and secure, scalable architectures. A deep understanding of microservices , domain-driven design , event-driven systems , and containerisation . Familiarity with architectural frameworks such More ❯

X Days a week Plymouth - willingness to undergo DV if required Role Overview Defence client requires an SC Cleared AI Engineer to build fully on-premises RAG systems using open-source technologies. You'll develop classified AI capabilities on air-gapped infrastructure with zero external dependencies. Key Responsibilities - Build end-to-end RAG pipelines on isolated defence networks … using open-source LLMs (Llama 3, Mistral, Qwen) - Deploy local vector stores (Chroma, FAISS, Milvus) with sensitive document ingestion pipelines - Host and optimise LLMs using vLLM/TGI on local GPU clusters without internet connectivity - Implement agent orchestration using LangChain/LangGraph in completely offline environments - Design secure document processing for classified materials with appropriate data sanitisation - Build … monitoring and evaluation systems that operate within air-gapped infrastructure Essential Requirements - Active SC Clearance (non-negotiable) - willingness to undergo DV if required - Demonstrable experience deploying open-source LLMs (Llama, Mistral, Falcon) on-premises - Expertise with local vector databases (Chroma, FAISS, Weaviate) in offline deployments - Strong vLLM/Text Generation Inference experience for high-throughput model serving - Proven More ❯

X Days a week Plymouth - willingness to undergo DV if required Role Overview Defence client requires an SC Cleared AI Engineer to build fully on-premises RAG systems using open-source technologies. You'll develop classified AI capabilities on air-gapped infrastructure with zero external dependencies. Key Responsibilities - Build end-to-end RAG pipelines on isolated defence networks … using open-source LLMs (Llama 3, Mistral, Qwen) - Deploy local vector stores (Chroma, FAISS, Milvus) with sensitive document ingestion pipelines - Host and optimise LLMs using vLLM/TGI on local GPU clusters without internet connectivity - Implement agent orchestration using LangChain/LangGraph in completely offline environments - Design secure document processing for classified materials with appropriate data sanitisation - Build … monitoring and evaluation systems that operate within air-gapped infrastructure Essential Requirements - Active SC Clearance (non-negotiable) - willingness to undergo DV if required - Demonstrable experience deploying open-source LLMs (Llama, Mistral, Falcon) on-premises - Expertise with local vector databases (Chroma, FAISS, Weaviate) in offline deployments - Strong vLLM/Text Generation Inference experience for high-throughput model serving - Proven More ❯

X Days a week Plymouth - willingness to undergo DV if required Role Overview Defence client requires an SC Cleared AI Engineer to build fully on-premises RAG systems using open-source technologies. You'll develop classified AI capabilities on air-gapped infrastructure with zero external dependencies. Key Responsibilities - Build end-to-end RAG pipelines on isolated defence networks … using open-source LLMs (Llama 3, Mistral, Qwen) - Deploy local vector stores (Chroma, FAISS, Milvus) with sensitive document ingestion pipelines - Host and optimise LLMs using vLLM/TGI on local GPU clusters without internet connectivity - Implement agent orchestration using LangChain/LangGraph in completely offline environments - Design secure document processing for classified materials with appropriate data sanitisation - Build … monitoring and evaluation systems that operate within air-gapped infrastructure Essential Requirements - Active SC Clearance (non-negotiable) - willingness to undergo DV if required - Demonstrable experience deploying open-source LLMs (Llama, Mistral, Falcon) on-premises - Expertise with local vector databases (Chroma, FAISS, Weaviate) in offline deployments - Strong vLLM/Text Generation Inference experience for high-throughput model serving - Proven More ❯

X Days a week Plymouth - willingness to undergo DV if required Role Overview Defence client requires an SC Cleared AI Engineer to build fully on-premises RAG systems using open-source technologies. You'll develop classified AI capabilities on air-gapped infrastructure with zero external dependencies. Key Responsibilities - Build end-to-end RAG pipelines on isolated defence networks … using open-source LLMs (Llama 3, Mistral, Qwen) - Deploy local vector stores (Chroma, FAISS, Milvus) with sensitive document ingestion pipelines - Host and optimise LLMs using vLLM/TGI on local GPU clusters without internet connectivity - Implement agent orchestration using LangChain/LangGraph in completely offline environments - Design secure document processing for classified materials with appropriate data sanitisation - Build … monitoring and evaluation systems that operate within air-gapped infrastructure Essential Requirements - Active SC Clearance (non-negotiable) - willingness to undergo DV if required - Demonstrable experience deploying open-source LLMs (Llama, Mistral, Falcon) on-premises - Expertise with local vector databases (Chroma, FAISS, Weaviate) in offline deployments - Strong vLLM/Text Generation Inference experience for high-throughput model serving - Proven More ❯

days per week in office) Maze is partnering with a stealth-mode startup that's rebuilding core banking from the ground up. They’re creating the world’s first open-source, AI-native "Thin Ledger"—set to replace legacy infrastructure at Tier 1 banks. We're looking for a Founding Site Reliability Engineer to drive the infrastructure behind … incident response AI-curious or AI-native: excited to build agent-powered ops Someone who is currently hands on (not someone primarily focused on strategy & people management) Passion for open-source, clean architecture Software Development experience (Bonus points for Go(Golang)) Bonus: background in financial systems, core banking, or regulated infra Why join: Huge ownership: build core infra … Work with a high-caliber team, fast-paced and product-minded founders who have worked in some of the most recognised tech businesses in the world. Help define an open-source platform from day one. Clear path to tech unicorn status with fruitful equity included. Recently raised 8 figures in funding. If your skillset matches, apply within. Please More ❯

days per week in office) Maze is partnering with a stealth-mode startup that's rebuilding core banking from the ground up. They’re creating the world’s first open-source, AI-native "Thin Ledger"—set to replace legacy infrastructure at Tier 1 banks. We're looking for a Founding Site Reliability Engineer to drive the infrastructure behind … incident response AI-curious or AI-native: excited to build agent-powered ops Someone who is currently hands on (not someone primarily focused on strategy & people management) Passion for open-source, clean architecture Software Development experience (Bonus points for Go(Golang)) Bonus: background in financial systems, core banking, or regulated infra Why join: Huge ownership: build core infra … Work with a high-caliber team, fast-paced and product-minded founders who have worked in some of the most recognised tech businesses in the world. Help define an open-source platform from day one. Clear path to tech unicorn status with fruitful equity included. Recently raised 8 figures in funding. If your skillset matches, apply within. Please More ❯

days per week in office) Maze is partnering with a stealth-mode startup that's rebuilding core banking from the ground up. They’re creating the world’s first open-source, AI-native "Thin Ledger"—set to replace legacy infrastructure at Tier 1 banks. We're looking for a Founding Site Reliability Engineer to drive the infrastructure behind … incident response AI-curious or AI-native: excited to build agent-powered ops Someone who is currently hands on (not someone primarily focused on strategy & people management) Passion for open-source, clean architecture Software Development experience (Bonus points for Go(Golang)) Bonus: background in financial systems, core banking, or regulated infra Why join: Huge ownership: build core infra … Work with a high-caliber team, fast-paced and product-minded founders who have worked in some of the most recognised tech businesses in the world. Help define an open-source platform from day one. Clear path to tech unicorn status with fruitful equity included. Recently raised 8 figures in funding. If your skillset matches, apply within. Please More ❯

days per week in office) Maze is partnering with a stealth-mode startup that's rebuilding core banking from the ground up. They’re creating the world’s first open-source, AI-native "Thin Ledger"—set to replace legacy infrastructure at Tier 1 banks. We're looking for a Founding Site Reliability Engineer to drive the infrastructure behind … incident response AI-curious or AI-native: excited to build agent-powered ops Someone who is currently hands on (not someone primarily focused on strategy & people management) Passion for open-source, clean architecture Software Development experience (Bonus points for Go(Golang)) Bonus: background in financial systems, core banking, or regulated infra Why join: Huge ownership: build core infra … Work with a high-caliber team, fast-paced and product-minded founders who have worked in some of the most recognised tech businesses in the world. Help define an open-source platform from day one. Clear path to tech unicorn status with fruitful equity included. Recently raised 8 figures in funding. If your skillset matches, apply within. Please More ❯

Provide best Customer experience in terms of responsiveness, resolution time, tone, and knowledge Support the customer throughout their entire lifecycle Provide expert-level technical support for customers using our Open Source Ledger and other backend modules. Troubleshoot complex issues, investigating and diagnosing problems quickly, and escalating them to the development team when necessary. Create and maintain detailed documentation … product teams to deliver seamless support and relay feedback for continuous improvement. Ability to prioritize and manage multiple tickets/issues Fluent in English Nice to have : Familiarity with open-source ecosystems, APIs, webhooks, or BE tools Basic understanding of financial services infrastructure (ledgers, reconciliation, transactions) Benefits We offer a competitive package including equity for employees. We organize … regular off-sites with the team in Europe and soon in the US! About FORMANCE : Formance is building the next-generation financial infrastructure - open-source, developer-first, and built to power the most ambitious fintech products of tomorrow. Formance is global native and serving enterprise companies around the globe, around the clock, to build and scale their financial More ❯

Provide best Customer experience in terms of responsiveness, resolution time, tone, and knowledge Support the customer throughout their entire lifecycle Provide expert-level technical support for customers using our Open Source Ledger and other backend modules. Troubleshoot complex issues, investigating and diagnosing problems quickly, and escalating them to the development team when necessary. Create and maintain detailed documentation … product teams to deliver seamless support and relay feedback for continuous improvement. Ability to prioritize and manage multiple tickets/issues Fluent in English Nice to have : Familiarity with open-source ecosystems, APIs, webhooks, or BE tools Basic understanding of financial services infrastructure (ledgers, reconciliation, transactions) Benefits We offer a competitive package including equity for employees. We organize … regular off-sites with the team in Europe and soon in the US! About FORMANCE : Formance is building the next-generation financial infrastructure - open-source, developer-first, and built to power the most ambitious fintech products of tomorrow. Formance is global native and serving enterprise companies around the globe, around the clock, to build and scale their financial More ❯

Provide best Customer experience in terms of responsiveness, resolution time, tone, and knowledge Support the customer throughout their entire lifecycle Provide expert-level technical support for customers using our Open Source Ledger and other backend modules. Troubleshoot complex issues, investigating and diagnosing problems quickly, and escalating them to the development team when necessary. Create and maintain detailed documentation … product teams to deliver seamless support and relay feedback for continuous improvement. Ability to prioritize and manage multiple tickets/issues Fluent in English Nice to have : Familiarity with open-source ecosystems, APIs, webhooks, or BE tools Basic understanding of financial services infrastructure (ledgers, reconciliation, transactions) Benefits We offer a competitive package including equity for employees. We organize … regular off-sites with the team in Europe and soon in the US! About FORMANCE: Formance is building the next-generation financial infrastructure - open-source, developer-first, and built to power the most ambitious fintech products of tomorrow. Formance is global native and serving enterprise companies around the globe, around the clock, to build and scale their financial More ❯

Provide best Customer experience in terms of responsiveness, resolution time, tone, and knowledge Support the customer throughout their entire lifecycle Provide expert-level technical support for customers using our Open Source Ledger and other backend modules. Troubleshoot complex issues, investigating and diagnosing problems quickly, and escalating them to the development team when necessary. Create and maintain detailed documentation … product teams to deliver seamless support and relay feedback for continuous improvement. Ability to prioritize and manage multiple tickets/issues Fluent in English Nice to have : Familiarity with open-source ecosystems, APIs, webhooks, or BE tools Basic understanding of financial services infrastructure (ledgers, reconciliation, transactions) Benefits We offer a competitive package including equity for employees. We organize … regular off-sites with the team in Europe and soon in the US! About FORMANCE: Formance is building the next-generation financial infrastructure - open-source, developer-first, and built to power the most ambitious fintech products of tomorrow. Formance is global native and serving enterprise companies around the globe, around the clock, to build and scale their financial More ❯

Who We Are At Ultralytics , we are shaping the future of Vision AI. Our groundbreaking YOLO (You Only Look Once) models are the world’s most widely used open-source object detection tools, empowering millions of developers and enterprises to build intelligent applications that see and understand the world. Now backed by a $30M Series A , we are … environment where autonomy and results go hand in hand. 💥 Why This Role and Why Now Be part of a once-in-a-decade AI success story with an enormous open-source following and clear product-market fit. Join at the moment when Ultralytics is transitioning from foundation building to large-scale global growth. Sell a product that engineers … action. Entrepreneurial mindset with comfort operating in fast-changing, high-growth environments. ✨ Nice-to-Haves Background in AI, Machine Learning, or Vision AI technologies. Familiarity with YOLO or other open-source developer ecosystems. Experience closing high-value enterprise deals of $100,000 or more. Exposure to international markets and global sales. Hands-on experience with HubSpot or Clay. More ❯

Who We Are At Ultralytics , we are shaping the future of Vision AI. Our groundbreaking YOLO (You Only Look Once) models are the world’s most widely used open-source object detection tools, empowering millions of developers and enterprises to build intelligent applications that see and understand the world. Now backed by a $30M Series A , we are … environment where autonomy and results go hand in hand. 💥 Why This Role and Why Now Be part of a once-in-a-decade AI success story with an enormous open-source following and clear product-market fit. Join at the moment when Ultralytics is transitioning from foundation building to large-scale global growth. Sell a product that engineers … action. Entrepreneurial mindset with comfort operating in fast-changing, high-growth environments. ✨ Nice-to-Haves Background in AI, Machine Learning, or Vision AI technologies. Familiarity with YOLO or other open-source developer ecosystems. Experience closing high-value enterprise deals of $100,000 or more. Exposure to international markets and global sales. Hands-on experience with HubSpot or Clay. More ❯

Who We Are At Ultralytics , we are shaping the future of Vision AI. Our groundbreaking YOLO (You Only Look Once) models are the world’s most widely used open-source object detection tools, empowering millions of developers and enterprises to build intelligent applications that see and understand the world. Now backed by a $30M Series A , we are … environment where autonomy and results go hand in hand. 💥 Why This Role and Why Now Be part of a once-in-a-decade AI success story with an enormous open-source following and clear product-market fit. Join at the moment when Ultralytics is transitioning from foundation building to large-scale global growth. Sell a product that engineers … action. Entrepreneurial mindset with comfort operating in fast-changing, high-growth environments. ✨ Nice-to-Haves Background in AI, Machine Learning, or Vision AI technologies. Familiarity with YOLO or other open-source developer ecosystems. Experience closing high-value enterprise deals of $100,000 or more. Exposure to international markets and global sales. Hands-on experience with HubSpot or Clay. More ❯

Who We Are At Ultralytics , we are shaping the future of Vision AI. Our groundbreaking YOLO (You Only Look Once) models are the world’s most widely used open-source object detection tools, empowering millions of developers and enterprises to build intelligent applications that see and understand the world. Now backed by a $30M Series A , we are … environment where autonomy and results go hand in hand. 💥 Why This Role and Why Now Be part of a once-in-a-decade AI success story with an enormous open-source following and clear product-market fit. Join at the moment when Ultralytics is transitioning from foundation building to large-scale global growth. Sell a product that engineers … action. Entrepreneurial mindset with comfort operating in fast-changing, high-growth environments. ✨ Nice-to-Haves Background in AI, Machine Learning, or Vision AI technologies. Familiarity with YOLO or other open-source developer ecosystems. Experience closing high-value enterprise deals of $100,000 or more. Exposure to international markets and global sales. Hands-on experience with HubSpot or Clay. More ❯

right tool to solve our biggest problems. What we offer: Competitive salary and benefits package. Discretionary bonus based on performance. Continued personal development through training and certification. We are open-source friendly, following open-source principles in our internal projects and encouraging contributions to external projects. Responsibilities: React Native Mobile App Ownership: Oversee the app's More ❯

enjoy solving complex challenges, we would love to hear from you. Nice to have: Publications: At top-tier ML/CV/NLP conferences (NeurIPS, ICML, ICLR, CVPR, ICCV) Open-source: Contributions to and experience in open-source projects. Startup experience: Experience with a startup work environment and wider ecosystem. Why join us? Work in an More ❯

enjoy solving complex challenges, we would love to hear from you. Nice to have: Publications: At top-tier ML/CV/NLP conferences (NeurIPS, ICML, ICLR, CVPR, ICCV) Open-source: Contributions to and experience in open-source projects. Startup experience: Experience with a startup work environment and wider ecosystem. Why join us? Work in an More ❯

enjoy solving complex challenges, we would love to hear from you. Nice to have: Publications: At top-tier ML/CV/NLP conferences (NeurIPS, ICML, ICLR, CVPR, ICCV) Open-source: Contributions to and experience in open-source projects. Startup experience: Experience with a startup work environment and wider ecosystem. Why join us? Work in an More ❯

enjoy solving complex challenges, we would love to hear from you. Nice to have: Publications: At top-tier ML/CV/NLP conferences (NeurIPS, ICML, ICLR, CVPR, ICCV) Open-source: Contributions to and experience in open-source projects. Startup experience: Experience with a startup work environment and wider ecosystem. Why join us? Work in an More ❯

enjoy solving complex challenges, we would love to hear from you. Nice to have: Publications: At top-tier ML/CV/NLP conferences (NeurIPS, ICML, ICLR, CVPR, ICCV) Open-source: Contributions to and experience in open-source projects. Startup experience: Experience with a startup work environment and wider ecosystem. Why join us? Work in an More ❯

enjoy solving complex challenges, we would love to hear from you. Nice to have: Publications: At top-tier ML/CV/NLP conferences (NeurIPS, ICML, ICLR, CVPR, ICCV) Open-source: Contributions to and experience in open-source projects. Startup experience: Experience with a startup work environment and wider ecosystem. Why join us? Work in an More ❯

enjoy solving complex challenges, we would love to hear from you. Nice to have: Publications: At top-tier ML/CV/NLP conferences (NeurIPS, ICML, ICLR, CVPR, ICCV) Open-source: Contributions to and experience in open-source projects. Startup experience: Experience with a startup work environment and wider ecosystem. Why join us? Work in an More ❯