Jack & Jill/External ATS

A leading reusable packaging provider in London seeks a Mobile Software Engineer to own the migration to Kotlin Multiplatform and impact waste reduction directly. The role involves developing a unified codebase for iOS and Android, collaborating on backend services, and maintaining client applications. The ideal candidate should have 1-2 years of mobile engineering experience, particularly with Kotlin, and a strong mindset for startup culture. The role offers a competitive salary and equity, contributing to meaningful environmental change.

Mobile Software Engineer (£40,000-£45,000 + Equity) Company: Cauli - UK's largest reusable packaging provider for the food service industry. Salary: £40,000-£45,000 + Equity Location: London, UK Job Description As our first dedicated mobile hire, you will eliminate single use waste by building the infrastructure for reuse. You'll own the migration to Kotlin Multiplatform, ship features across consumer and client facing apps, and work directly with our technical lead. This is a hands on role where your code directly impacts plastic pollution reduction. Why This Role Is Remarkable Direct ownership of a high stakes migration to Kotlin Multiplatform (KMP), shaping the future architecture of our mobile ecosystem from day one. Join a mission driven team that has already prevented 1.6 million pieces of waste, working with prestigious clients such as the NHS, BT, and major universities. Receive meaningful early employee equity in a fast growing startup led by a Forbes 30 Under 30 founder, ensuring you share in the company's long term success. What You Will Do Lead the migration of separate iOS and Android applications into a unified Kotlin Multiplatform codebase to streamline cross platform feature delivery. Develop and maintain our point of sale client application using Kotlin and integrate lightweight web apps with Apple and Google Wallets. Collaborate across the stack by contributing to PHP/Laravel backend services and supporting IoT hardware running Python on Linux SBCs. The Ideal Candidate Professional experience (1-2 years) in mobile engineering with production level Kotlin skills and a solid foundation in native Android development. Demonstrated enthusiasm for or experience with Kotlin Multiplatform, including the ability to handle KMP generated iOS frameworks and basic SwiftUI integration. Versatile, startup ready mindset with the ability to navigate REST API integrations and a willingness to touch backend or hardware code when necessary.

A promising AI startup in London is seeking a Senior ML Engineer to design and implement production ML systems for high-profile clients. You will play a crucial role in transforming marketing operations through cutting-edge AI solutions. Ideal candidates possess 4-8 years of experience in ML system development, with a strong foundation in Python and specialized knowledge in RAG and LLM technologies. This is a unique opportunity to significantly impact major brands while working in a dynamic, well-funded environment.

An AI infrastructure startup is seeking a Backend/Infrastructure Engineer as their first hire. In this critical role, you will architect the core infrastructure for high-performance systems, directly addressing the 'forgetful agent' problem. The ideal candidate will have extensive experience with performance-sensitive languages and distributed systems. You will collaborate closely with the founding team to develop scalable AI solutions. This position offers the chance to make a significant impact in a cutting-edge technology environment.

Job Title Founding Engineer Salary £60k-£90k + Equity Company Description Corgi - YC S24 full-stack AI insurance carrier Job Description Join the Strategic Projects team at a YC S24 startup rebuilding the $6 trillion insurance industry from scratch. As a founding engineer, you will own entire product surfaces, architecting AI-native systems that handle real-world risk and regulation. This is a high intensity role for builders who thrive on autonomy and extreme shipping speed. Location London, UK Why this role is remarkable Work at a hyper growth startup that recently raised a $108M Series A at a $630M valuation with over $40M in ARR. Join an elite engineering culture alongside veterans from Google, Databricks, and Perplexity AI, moving at a pace that defines the industry's cutting edge. Take true founding ownership of a licensed insurance carrier where your code directly manages millions in capital and disrupts 30 year old legacy infrastructure. What you will do Architect and ship end to end systems using Python, TypeScript, Django Ninja, and React to automate underwriting and claims. Collaborate with AI as a primary architectural partner to achieve order of magnitude improvements in development velocity and system capability. Build compliant by design features that turn complex US insurance regulations into a scalable competitive moat for the platform. The ideal candidate 2-4 years of experience shipping production grade systems at high growth startups or top tier technology companies. An AI native workflow where LLMs are used for complex architectural reasoning and rapid prototyping, not just basic code completion. High ownership mentality with a track record of self initiated projects and the ability to thrive in high ambiguity, intense environments. Next steps Step 1. Visit our website. Step 2. Click 'Talk to Jack'. Step 3. Talk to Jack so he can understand your experience and ambitions. Step 4. Jack will make sure Jill considers you for this role. Step 5. If Jill thinks you're a great fit and her client wants to meet you, they will make the introduction. Step 6. If not, Jack will find you excellent alternatives.

This is a job that Jill, our AI Recruiter, is recruiting for on behalf of one of our customers. She will pick the best candidates from Jack's network The next step is to speak to Jack. Job Title: ML Engineer Company Description: Passionfruit - Series A AI startup ($13.3M raised) backed by Seaya and Playfair Job Description: As the most senior ML Engineer on a high-impact team, you will design and ship production LLM systems that automate complex marketing operations for Fortune 500 clients like PepsiCo and HSBC. You will build agentic workflows with persistent memory and tool use, transforming how global brands analyze data and execute campaigns. Location: London, UK Why this role is remarkable Take meaningful ownership of architecture and model selection as the most senior ML engineer on a small, elite technical team. Work at a well-funded Series A startup ($13.3M raised) backed by top-tier investors like Firstminute Capital and Seaya Ventures. Directly impact the marketing operations of some of the world's largest brands, moving them from manual "gut-feel" processes to AI-native precision. What you will do Develop and deploy production-grade ML/LLM systems and agentic workflows with persistent memory and sophisticated tool-use capabilities. Integrate models with live enterprise data sources including Google Ads, GA4, Meta Ads, and various CRM and analytics platforms. Build and refine evaluation frameworks, retrieval systems, and fine-tuning processes specifically optimized for the marketing domain. The ideal candidate Possesses 4-8 years of hands-on experience building and shipping production ML systems, with deep expertise in RAG and LLM agents. Demonstrates strong engineering fundamentals in Python and API development, with the ability to thrive in a fast-paced, high-ownership environment. Brings a proven track record of solving ambiguous technical challenges, ideally with exposure to adtech, marketing analytics, or Elixir. Who are Jack & Jill? Ok, I'll go first. I'm Jack, an AI that gets to know you on a quick call, learning what you're great at and what you want from your career. Then I help you land your dream job by finding unmissable opportunities as they come up, supporting you with applications, interview prep, and moral support. And I'm Jill, an AI Recruiter who talks to companies to understand who they're looking to hire. Then I recruit from Jack's network, making an introduction when I spot an excellent candidate. Next steps Visit our website. Click 'Talk to Jack'. Talk to Jack so he can understand your experience and ambitions. Jack will make sure Jill (the AI agent working for the company) considers you for this role. If Jill thinks you're a great fit and her client wants to meet you, they will make the introduction. If not, Jack will find you excellent alternatives. All for free. We never post fake jobs This isn't a trick. This is an open role that Jill is currently recruiting for from Jack's network. Sometimes Jill's clients ask her to anonymize their jobs when she advertises them, which means she can't share all the details in the job description. We appreciate this can make them look a bit suspect, but there isn't much we can do about it. Give Jack a spin! You could land this role. If not, most people find him incredibly helpful with their job search, and we're giving his services away for free.

A high-growth AI implementation firm in London is seeking an AI Engineer to bridge frontier AI and real-world business operations. In this role, you will deploy production-grade AI systems for various clients while collaborating with experienced founders. The ideal candidate has over 4 years of full-stack software engineering experience and a strong curiosity for business operations. This position offers significant variety and ownership, providing opportunities to impact diverse industries with innovative AI solutions.

Job Title AI Engineer Salary £85K Equity Company Description Stackfix - High growth AI implementation firm backed by Tier 1 investors Job Description You will bridge the gap between frontier AI and real world business operations. Instead of building generic SaaS tools, you will deploy production grade AI systems for PE funds and manufacturers. Working directly with repeat founders who sold companies to TikTok, you will own the end to end process of transforming workflows and growing client profits. Location London, UK Why this role is remarkable Learn directly from two exited founders (including a former TikTok engineering leader) in a high intensity, apprenticeship style environment. Gain deep expertise in frontier AI by building production systems that handle real transactions, rather than just experimenting with tutorials. Enjoy significant variety and ownership, shipping impactful solutions across diverse industries such as logistics, e commerce, and private equity within 4 9 month cycles. What you will do Build and deploy sophisticated AI systems and full stack software that manage high volume production workflows for enterprise clients. Interface directly with leadership at client sites to scope workflows and present high impact AI transformation strategies. Own the full product lifecycle from initial technical discovery and architecture to shipping production ready systems that generate real revenue. The ideal candidate 4+ years of full stack software engineering experience with a proven track record of shipping production grade systems. Demonstrates high agency and a passion for building through side projects, open source contributions, or technical content creation. Exhibits a strong curiosity for business operations and a record of high performance in challenging environments (professional or personal). Next steps Visit our website. Click Talk to Jack . Talk to Jack so he can understand your experience and ambitions. Jack will make sure Jill (the AI agent working for the company) considers you for this role. If Jill thinks you're a great fit and her client wants to meet you, they will make the introduction. If not, Jack will find you excellent alternatives. All for free.

This is a job that Jill, our AI Recruiter, is recruiting for on behalf of one of our customers. She will pick the best candidates from Jack's network. The next step is to speak to Jack. Lead Backend Engineer Company Description LightWork AI - VC-backed startup building the AI operating system for property management. Job Description As the most senior backend engineer, you will architect and build the scalable services powering Felicity, an AI assistant automating 80-90% of property management workflows. You will design event-driven systems in Node.js/TypeScript, integrate advanced LLMs, and establish the technical standards for a high-performing engineering team in a fast-scaling startup environment. Location London, UK Why this role is remarkable Join as the most senior backend authority working directly with a founding team from Revolut, ESG Book, and Mimica. Shape the technical backbone of a platform disrupting a massive industry where 75% of time is currently wasted on manual admin. Lead the transition from pilot phase to scale, owning the architecture and engineering culture of a potential AI unicorn. What you will do Architect and build scalable backend systems and RESTful APIs using Node.js, TypeScript, and PostgreSQL. Design and maintain microservice and event-driven architectures that support real-time operational workflows and AI integrations. Lead technical strategy, mentor engineers, and conduct code reviews to ensure production-grade reliability and performance. The ideal candidate 7+ years of professional backend experience with deep expertise in Node.js and TypeScript ecosystems. Proven track record of designing and operating production systems in microservice or event-driven architectures. Strong leadership ability with experience mentoring engineers and translating complex business requirements into robust technical solutions. Who are Jack & Jill? Ok, I'll go first. I'm Jack, an AI that gets to know you on a quick call, learning what you're great at and what you want from your career. Then I help you land your dream job by finding unmissable opportunities as they come up, supporting you with applications, interview prep, and moral support. And I'm Jill, an AI Recruiter who talks to companies to understand who they're looking to hire. Then I recruit from Jack's network, making an introduction when I spot an excellent candidate. Next steps Step 1. Visit our website. Step 2. Click 'Talk to Jack'. Step 3. Talk to Jack so he can understand your experience and ambitions. Step 4. Jack will make sure Jill (the AI agent working for the company) considers you for this role. Step 5. If Jill thinks you're a great fit and her client wants to meet you, they will make the introduction. Step 6. If not, Jack will find you excellent alternatives. All for free. We never post fake jobs This isn't a trick. This is an open role that Jill is currently recruiting for from Jack's network. Sometimes Jill's clients ask her to anonymize their jobs when she advertises them, which means she can't share all the details in the job description. We appreciate this can make them look a bit suspect, but there isn't much we can do about it. Give Jack a spin! You could land this role. If not, most people find him incredibly helpful with their job search, and we're giving his services away for free.

A high-growth startup in London is seeking a Founding Engineer to architect and ship end-to-end systems utilizing Python, TypeScript, Django Ninja, and React. The ideal candidate will have 2-4 years of experience in high-growth environments and a strong understanding of AI workflows. You will play a pivotal role in automating underwriting, collaborating with AI for development speed, and ensuring compliance with complex regulations, directly managing substantial capital within the insurance sector.

Job Title Backend/Infrastructure Engineer Company Description Mubit - Well-funded AI infrastructure startup building the operational memory layer for production agents. Job Description As the first engineering hire, you will architect Mubit's core infrastructure from scratch. You'll build high-performance systems for sub-80ms memory retrieval and shared state management, directly solving the "forgetful agent" problem. This role involves deep distributed systems work, SDK development, and close collaboration with the founding team to scale production AI agent fleets. Location London, UK Why this role is remarkable Founding engineer impact: As hire number one, you co own the architecture and technical direction of a critical infrastructure layer for the AI era. High performance engineering: Tackle complex distributed systems challenges where sub 80ms latency is the baseline requirement for production agents. On site collaboration: Build alongside a well funded founding team in a high energy Canary Wharf office, fostering rapid iteration and deep technical ownership. What you will do Design and implement the core storage and retrieval architecture to handle agent execution history at massive scale. Build and maintain the SDK that developers use to integrate Mubit with frameworks like LangGraph, CrewAI, and AutoGen. Profile and optimize system bottlenecks to ensure consistent performance under heavy load while scaling infrastructure 100x. The ideal candidate Proven experience building and running high scale, latency sensitive production systems using performance oriented languages like Rust, Go, or C++. Deep understanding of distributed systems, storage engine trade offs, and serving data within a hot execution loop. A self directed builder who thrives in ambiguity and has extensive experience with LLM orchestration frameworks and agentic memory patterns.

Job Title QA & Test Engineer Company Description SAIF Autonomy Ltd - VC backed AI safety platform Job Description You will own the verification and test program for NEXUS, a runtime assurance platform for autonomous systems. Working at the intersection of Physical AI and safety critical engineering, you will build a test function from scratch, defining processes and writing artifacts to achieve DO 178C certification for drones, maritime, and space applications. Location Oxfordshire, UK Why this role is remarkable Shape the safety infrastructure for the future of Physical AI, moving autonomous systems from labs to high stakes real world deployment. Join a fast growing startup backed by Fusion Fund that has already secured contracts with DSTL (UK MoD), the European Space Agency, and Zenzic. Enjoy high autonomy and ownership by building a QA department from the ground up rather than slotting into a pre existing corporate structure. What you will do Define and execute the verification strategy for the NEXUS platform as it progresses through DO 178C DAL B and DAL A certification. Perform requirements based testing and structural coverage analysis using specialized tools like Rapita, Codebeamer, and Matlab Simulink. Interface directly with airworthiness authorities such as the MAA and EASA to ensure compliance for airborne and autonomous platforms. The ideal candidate Extensive experience in safety critical software verification within aerospace (DO 178C), automotive (ISO 26262), or defence (DEF STAN ) industries. Proficient in structural coverage, timing analysis, and MISRA C/C++ standards using tools like Rapita, LDRA, VectorCAST, or Polyspace. Must be a UK national or hold existing SC clearance, with a preference for candidates who thrive in a high impact, 10 person startup environment. Next steps Visit our website. Click 'Talk to Jack'. Talk to Jack so he can understand your experience and ambitions. Jack will make sure Jill (the AI agent working for the company) considers you for this role. If Jill thinks you're a great fit and her client wants to meet you, they will make the introduction. If not, Jack will find you excellent alternatives. All for free. We never post fake jobs. This isn't a trick. This is an open role that Jill is currently recruiting for from Jack's network. Sometimes Jill's clients ask her to anonymize their jobs when she advertises them, which means she can't share all the details in the job description. We appreciate this can make them look a bit suspect, but there isn't much we can do about it. Give Jack a spin! You could land this role. If not, most people find him incredibly helpful with their job search, and we're giving his services away for free.

An AI safety platform company based in the UK is seeking a QA & Test Engineer to own the verification and test program for their NEXUS platform. The role involves defining testing strategies for DO-178C certification, performing structural coverage analysis, and collaborating with airworthiness authorities. Candidates should have extensive experience in safety-critical environments like aerospace or automotive and must be a UK national or hold SC clearance. This position offers high autonomy as you build the QA department in a growing startup.

Job Title: Founding Engineer Company: Delfa.ai - Air Street Capital-backed AI startup Location: London, UK Job Description: As a Founding Engineer, you will build and scale autonomous AI agents that automate clinical trial recruitment. You will own complex technical systems from architecture to deployment, directly impacting how life saving treatments reach patients. Working in a high talent density environment, you will solve 0 1 engineering challenges while scaling a product with seven figure ARR. Why this role is remarkable: Join a high growth startup with seven figure ARR growing 25% MoM, backed by an oversubscribed $3.8M seed round from tier one AI investor Air Street Capital. Work alongside a world class team including foundation model researchers from ETH Zurich, medical doctors, and engineers who have deployed production AI at J&J and Exscientia. Take full ownership of critical technical decisions and build systems from scratch that solve the $120 billion bottleneck in clinical trial patient recruitment. What you will do: Architect and scale core systems powering AI agents, managing everything from voice interactions to intelligent workflow orchestration across clinical trial sites. Drive complex engineering projects end to end, taking full responsibility for product features from initial design to production deployment and monitoring. Collaborate with a multidisciplinary team of AI researchers and clinical experts to build robust, reliable tools using a modern stack including FastAPI, Temporal, and LLMs. The ideal candidate: At least 3+ years of full stack engineering experience with a proven track record of building and shipping high quality software products at high speed. Strong ownership mindset with the ability to navigate ambiguous 0 1 environments and translate customer problems into scalable technical solutions. Deep builder instincts evidenced by significant side projects, open source contributions, or experience with modern tools like TypeScript, React, and PostgreSQL.

A VC-backed startup in London is looking for a Lead Backend Engineer to architect scalable services for their AI platform. In this role, you will design event-driven systems using Node.js and TypeScript, mentor engineers, and shape the technical standards for a high-performing team. Ideal candidates should have over 7 years of backend experience, including expertise in microservices. This position offers the opportunity to work directly with a founding team and help transition the project from pilot to scale.

Job Title: Active Device Specialist Salary: £75K - £85K + Equity Company Description: Scarlet - Creandum-backed healthtech startup Job Description: As Scarlet's first Active Device Specialist, you will pioneer the expansion from software into hardware medical devices. You'll design assessment processes from scratch, evaluate technical documentation for innovative active devices, and serve as the internal authority on IEC 60601-1 standards, directly accelerating market access for life saving medical technology. Location: London, UK Why this role is remarkable Rare opportunity to be the founding specialist for a new function, transitioning a successful software focused Notified Body into the hardware space. Join a high growth startup backed by top tier investors like Creandum with exponentially growing revenue and established product market fit. Significant impact on global healthcare by defining the regulatory path for the world's most advanced medical hardware and AI integrated devices. What you will do Lead the creation and optimization of Scarlet's internal processes for assessing and certifying active medical hardware devices. Authorize and review technical documentation for cutting edge active devices to ensure compliance with international safety and performance standards. Act as the primary technical expert in active devices, defending Scarlet's methodologies to external regulatory authorities and global hardware manufacturers. The ideal candidate Holds a Bachelor's degree or higher in Biomedical, Electrical, or Mechanical Engineering with a deep understanding of active device architecture. Brings 4+ years of professional experience in manufacturing, auditing, or research specifically focused on active medical devices and hardware testing. Demonstrates expert level knowledge of the IEC 60601 1 family of standards and experience implementing these requirements in a regulatory or design context.

A fast-growing AI data intelligence startup in London is seeking a Forward Deployed Engineer to lead enterprise-scale AI projects. This role involves bridging strategy and technical execution while partnering with C-suite stakeholders. The ideal candidate has over 2 years of consulting experience, a strong analytical background, and thrives in dynamic environments. Opportunity to work with a high-caliber team and shape product trajectory in a fast-paced setting.

A promising AI startup is seeking a Founding Engineer in London to build and scale AI agents for clinical trial recruitment. This role involves architecting and managing complex systems, driving engineering projects, and collaborating with experts. The ideal candidate has over 3 years of full-stack engineering experience, a strong ownership mindset, and familiarity with modern tools like FastAPI and TypeScript. Join a high-growth environment supported by a renowned investment to make a significant impact in healthcare.

Job Title Forward Deployed Engineer Salary £120k Company Description Deducta - Fast-growing AI data intelligence startup Job Description Join an elite team of Rhodes Scholars and ex-MBB consultants at Deducta, an AI-powered platform transforming how global enterprises manage complex spend data. As a Forward Deployed Engineer, you will bridge the gap between high-level strategy and technical execution, embedding with C suite stakeholders to deploy agentic AI solutions that deliver measurable business outcomes. Location London, UK Why this role is remarkable Work directly with a high calibre founding team including Rhodes Scholars and former Bain consultants at a well funded, early stage startup. Transition from slide making to true ownership by managing enterprise scale AI deployments end to end for household name global clients. Enjoy a high autonomy environment where your consulting toolkit and technical rigour directly shape the product trajectory and company culture. What you will do Lead enterprise data transformation projects, from aligning C suite and VP level stakeholders to resolving front line technical deployment blockers. Partner with the commercial team to drive pre sales engagements, demonstrating product value and structuring complex technical deals. Map mission critical business challenges and deploy Deducta's agentic AI platform to cleanse, classify, and standardise fragmented global spend data. The ideal candidate 2+ years of experience at a top tier consulting firm (MBB or equivalent) with a proven track record of managing senior client relationships. Strong quantitative foundation with a degree in Computer Science, Mathematics, or Engineering, or equivalent experience in analytical fields like IB or PE. High agency operator who thrives in ambiguous environments and demonstrates "unreasonable hospitality" toward clients and teammates alike. Next steps Visit our website. Click 'Talk to Jack'. Talk to Jack so he can understand your experience and ambitions. Jack will make sure Jill considers you for this role. If Jill thinks you're a great fit and her client wants to meet you, they will make the introduction. If not, Jack will find you excellent alternatives. All for free.