Polyglot Engineer (JS/Python/Go)

YLD

Location: UK Department: Engineering Employment Type: Permanent 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 enthusiastic. You should be skilled in problem-solving and experienced in designing scalable, resilient, and fault-tolerant architectures. You’re also an effective communicator and a strong team player. Together with your team, you’ll thrive in a fast-paced engineering environment, delivering outstanding results and exciting projects. YOUR DAY-TO-DAY RESPONSIBILITIES WILL LOOK LIKE THIS: * Crafting excellent products! You will be building new features that meet the needs of our clients and customers; * Continuously delivering changes to products, as our client is moving to a full CI/CD model; * Working closely with your team, regularly collaborating and on engineering initiatives, to continually push yourselves to be better; * Learning, growing, and mentoring the engineering team to accelerate their career growth and encourage them to progress; * Working with the Lead to architect, design, build, and deliver highly available, always-on, zero downtime products; * Being responsible for the production operation and monitoring of products in line with SLAs; * Driving good practices within your team, making an impact on the whole department; * Participating in regular show and tells, promoting your work to both your department and the wider company. PREFERRED SKILLS * Proficiency in JavaScript/TypeScript, Python, and/or Go, with the ability to rapidly learn new languages; * Experience with modern frameworks across the stack (FastAPI, Gin, Express, etc.); * Production experience with React, modern build tools, state management, responsive design, and accessibility standards; * Comprehensive testing experience (unit, integration, E2E, security) and performance optimization; * Scalable system design patterns, load balancing, and high-availability architectures; * Database design and optimization (both relational and NoSQL); * API development (REST, GraphQL, gRPC) and event-driven architectures; * Caching strategies and message queue systems (Redis, Kafka, RabbitMQ); * Cloud platforms (AWS, Azure, GCP) with containerisation (Docker, Kubernetes); * CI/CD pipelines and Infrastructure as Code (Terraform, CloudFormation); * Monitoring, observability, and performance optimisation tools; * You can keep a cool head when debugging production issues; * Use AI tools to augment your work, applying sound judgement to adopt emerging technologies where they genuinely add value and increase your impact as an engineer. YOU SHOULD APPLY IF YOU ARE: * Self-motivated, proactive and always looking for ways to improve and develop yourself; * A good communicator, both in writing and verbally. You’ll be able to explain technical ideas and concepts in business-friendly language. * Detail-oriented; * Possess strong problem-solving skills that balance innovation with pragmatic technology choices to solve business needs; * Used to working in a team-oriented, collaborative environment; * Analytical and problem-solving-oriented; * A genuine believer in diversity and fairness. Benefits you’ll receive: * Company Private Health care (currently provided by Vitality) * Enhanced fully paid maternity and paternity leave for up to 6 months * 25 days annual holiday (excluding Public Holidays) * £2000 annual allowance for Training/Conferences * £300 annual allowance for additional hardware * Mental Health support: access to Oli app * Meditation/Sleep support: Headspace or Calm app subscription * Bonus (depending on Company performance and results) * Company laptop * Generous referral schemes Our typical Recruitment Process looks like this: * 1st Interview with someone from the Talent team (30/45 mins) * Technical Interview with our Senior Developers (1h30) Get a glimpse of what it's like working at YLD! 🤳 Check out our LinkedIn page We live and breathe our values, and know you will too: * Growing every day * Including everyone * Relationships built on honesty and ethics * Inspiring solutions * Winning together We’re an equal-opportunity employer and value diversity in all its forms. We do not discriminate based on race, religion, colour, national origin, gender, sexual orientation, pregnancy or maternity, age, marital status, or disability. We also offer a remote-first working environment, with flexible working and work–life balance as standard for all employees.

PhysicsX

ABOUT US PhysicsX is a deep-tech company with roots in numerical physics and Formula One, dedicated to accelerating hardware innovation at the speed of software. We are building an AI-driven simulation software stack for engineering and manufacturing across advanced industries. By enabling high-fidelity, multi-physics simulation through AI inference across the entire engineering lifecycle, PhysicsX unlocks new levels of optimization and automation in design, manufacturing, and operations — empowering engineers to push the boundaries of possibility. Our customers include leading innovators in Aerospace & Defense, Materials, Energy, Semiconductors, and Automotive. THE ROLE PhysicsX is a deep-tech company with roots in numerical physics and Formula One, dedicated to accelerating hardware innovation at the speed of software. We are building an AI-driven simulation software stack for engineering and manufacturing across advanced industries. By enabling high-fidelity, multi-physics simulation through AI inference across the entire engineering lifecycle, PhysicsX unlocks new levels of optimization and automation in design, manufacturing, and operations, empowering engineers to push the boundaries of possibility. Our customers include leading innovators in Aerospace, Materials, Energy, Semiconductors, and Automotive. THE ROLE PhysicsX is building a platform that enables Data Scientists and Simulation Engineers to build, train, and deploy Deep Physics Models. Our platform serves multiple tenants across highly regulated industries, making robust identity, access control, and operational visibility foundational to everything we do. We're looking for a Senior Software Engineer to join our Core Services team, the team building the foundational primitives that gives our customers superpowers they've never had before. For decades, engineers have been trapped using siloed, rigid tools from the 90s. We're changing that by enabling secure, permissioned collaboration at the frontier of AI. You'll design and build the enterprise grade systems that make this possible. From fine-grained permissions to instrumentation, you'll create the primitives that every product across PhysicsX adopts, ensuring every user, service, and agentic workflow is securely identified, correctly scoped, and fully observable. You'll own the infrastructure that keeps our platform trustworthy, transparent, and ready for the future of manufacturing and engineering. WHAT YOU WILL DO * Design and implement authentication and authorisation systems, including identity provider integrations, token management, session handling, and SSO flows. * Architect and build fine-grained role-based and attribute-based access control (RBAC/ABAC) models that scale across multi-tenant environments. * Own the platform's permissions layer end-to-end: from policy definition and enforcement through auditing and compliance reporting. * Build and maintain telemetry infrastructure distributed tracing, structured logging, metrics collection, and alerting, to provide deep observability across services and environments. * Define and enforce security standards across APIs and services, including schema governance, data segregation, and least-privilege access patterns. * Design and implement identity and access patterns for AI agents, including MCP authentication, agent impersonation flows, and system account models that allow agents to act securely on behalf of users in a regulated, multi-tenant environment. * Contribute to the design of multi-service architectures, ensuring authentication and authorisation concerns are cleanly integrated and consistently enforced across both human and agentic workflows. * Drive best practices in CI/CD, automated testing, observability, and infrastructure-as-code. Build and maintain deployment pipelines, including zero-downtime and multi-service deployments. * Author and review Technical Decision Records. Participate in technology reviews to evaluate and adopt new tools and approaches. * Mentor junior and mid-level engineers, facilitate technical discussions, and build consensus around architectural decisions. WHAT YOU BRING TO THE TABLE * A passion for the craft, you're driven by engineering excellence and committed to fostering that culture across the team. * Strong software engineering foundations, solid grasp of algorithms, data structures, and system design. You write clean, maintainable, testable code and have strong command of Golang and Python. * Authentication and identity expertise, hands-on experience building or integrating identity and access management systems (e.g., Keycloak, Auth0, Okta). Deep understanding of OAuth 2.0, OIDC, SAML, and token-based authentication flows. Ability to effectively leverage cloud provider IAM systems (e.g., AWS IAM, GCP IAM, Azure AD). * Authorisation and permissions design, proven experience implementing RBAC, ABAC, or policy-as-code frameworks (e.g., OPA/Rego, Cedar) in production multi-tenant systems. * Telemetry and observability, experience designing and operating metrics, tracing, and logging pipelines (e.g., OpenTelemetry, Prometheus, Grafana, Jaeger). You understand what it takes to make distributed systems genuinely observable. * Kubernetes and GitOps, strong working knowledge of Kubernetes and ArgoCD, including deploying, managing, and troubleshooting services in production clusters. * API and service design maturity, experience designing multi-service systems with attention to schema governance, forward compatibility, and secure data access patterns. Proven ability to develop schema drift mitigation strategies with minimal impact to dependent clients (e.g., forward-compatible schemas, ACLs, ambassador sidecars). * Agent governance awareness, understanding of how identity and permissions extend to agentic systems, including MCP auth, impersonation, system accounts, and scoped token delegation. * Security awareness, familiarity with threat modelling, secure coding practices, and participating in security testing and compliance workflows. * CI/CD and deployment expertise, hands-on experience building and optimising CI/CD pipelines, including multi-service and zero-downtime deployments across numerous customer environments. * Communication and collaboration, excellent communication skills to work across teams, understand requirements from research scientists and product stakeholders, and translate them into technical specifications. * AI-native mindset, you follow the frontier of agentic systems and AI tooling. You naturally think about how infrastructure needs to evolve when agents, not just humans, are the consumers of your APIs and services. You actively use AI coding tools (e.g., Copilot, Cursor, Claude Code) in your daily workflow and see them as a force multiplier, not a novelty. * Incremental mindset, you work in small steps toward larger goals, driving change through continuous improvement rather than massive redesigns. You can zoom in on details and zoom out to see the big picture. IDEALLY * Polyglot programming, deep expertise in Python and Golang, with exposure to other languages such as Rust or C++. * Advanced Kubernetes, ability to leverage resources that extend the Kubernetes API (e.g., CRDs, Operators) and infrastructure configuration tools (Crossplane, Helm charts). * Infrastructure flexibility, understanding of what it takes to build software that runs in cloud, on-premises, and air-gapped environments. * Advanced testing, experience with fuzzing, deterministic simulation testing, or fault injection in production systems. What we offer Build what actually matters Help shape an AI-native engineering company at a formative stage, tackling problems that genuinely matter for industry and society. This is work with real-world impact - and something you can be proud to stand behind. Learn alongside exceptional people Work with a high-caliber, collaborative team of engineers, scientists, and operators who care deeply about doing great work, and about helping each other get better. We come from diverse backgrounds, but we share a commitment to operating at the highest level and addressing some of the most complex challenges out there. If you’re ambitious, thoughtful, and driven by impact, you’ll feel at home. Influence over hierarchy We operate with a flat structure: good ideas win - wherever they come from. Questioning assumptions and challenging the status quo isn’t just welcomed, it’s expected. Sustainable pace, long-term ambition Building meaningful technology is a marathon, not a sprint. We believe in balancing focused, ambitious work with a life beyond it. Our hybrid model blends time together in our Shoreditch office with work-from-home days, giving you the flexibility to work sustainably while staying connected in person. And it doesn’t stop there … 🚀 Equity options - share meaningfully in the company you’re helping to build. 🏦 10% employer pension contribution - because investing in future matters. 🍽️ Free office lunches - to keep you energised and focused. 👶 Enhanced parental leave - 3 months full pay paternity and 6 months full pay maternity leave, to provide extra flexibility during the moments that matter most. 🍼 YellowNest nursery scheme - to help working parents manage childcare costs. ☀️ 25 days of Annual Leave (+ Public Holidays) - because taking time to rest matters. 🏥 Private medical insurance - 100% employee cover, giving you complete peace of mind. 💪 Wellhub Subscription - gain access to thousands of gyms, classes and wellness apps, supporting both physical and mental wellbeing. 👀 Eye tests - because good work depends on good health. 📈 Personal development - dedicated support for learning, development, and leveling up over time. 💛 Employee Assistance Programme (EAP) - confidential wellbeing support, available whenever you need it. 🚲 Bike2Work scheme and 🚆 Season ticket loan - to make getting to work easier and greener. 🚗 Octopus EV salary sacrifice - for a simpler, more sustainable way to drive electric. 🔎 Watch this space, we’re continuing to build this as we grow…   We value diversity and are committed to equal employment opportunity regardless of sex, race, religion, ethnicity, nationality, disability, age, sexual orientation or gender identity. We strongly encourage individuals from groups traditionally underrepresented in tech to apply. To help make a change, we sponsor bright women from disadvantaged backgrounds through their university degrees in science and mathematics.    We collect diversity and inclusion data solely for the purpose of monitoring the effectiveness of our equal opportunities policies and ensuring compliance with UK employment and equality legislation. This information is confidential, used only in aggregate form, and will not influence the outcome of your application.

Adsquare

INTRO At Adsquare, our mission is driven by our core focus: * Passion – Solving complex challenges with great people, tech, and data. * Niche – Location Intelligence for Programmatic Advertisers. Our core values are integral to everything we do: * Drive: We turn ambition into action. * Resilience: We adapt, persevere, and grow stronger. * No BS: We value honesty, transparency, and clear communication. * Humble: We choose modesty over vanity and let results speak for themselves. * Moral Compass: We do the right thing with fairness, integrity, and respect. We seek candidates who not only bring top-tier technical expertise but also embody these values in every aspect of their work. ABOUT THE TEAM We are looking for a Staff Data Analytics Engineer to join our technical proficiency track. This is a highly technical, Individual Contributor (IC) role. You will act as the Technical Lead for your squad—making critical architectural decisions, defining engineering standards, and driving cross-squad collaboration—without the responsibilities of people management. You will be the technical north star for the team, approaching extremely complex data problems with a rigorous software engineering mindset. You will design, build, and oversee production-grade data platforms that process massive volumes of geo-spatial data, audience attributes, and geo-location time-series data. YOUR PROFILE We are looking for an exceptional engineer who has a proven track record of acting as a technical leader and domain expert in heavy data environments. Must-Have Skills: * 7+ years of experience in Data Engineering, Analytics Engineering, or Backend Development with a deep focus on massive data systems. * Geo-Spatial & Time-Series Expertise: Proven, hands-on experience handling massive datasets specifically involving geo-spatial (GIS) data, audience attributes, and high-frequency time-series data. * Advanced Software Engineering (Python): Mastery of Python beyond standard data scripting. You write highly modular, object-oriented code. You have deep, practical experience with Test-Driven Development (TDD), mocking, exception handling, and performance profiling, functional programming. * Architectural Vision: Deep expertise in designing scalable data architectures using both relational and horizontally scalable data warehouses/lakehouses (e.g., Snowflake, Redshift, Athena, StarRocks, Iceberg). You deeply understand query execution plans, partitioning, clustering, and cloud cost governance. * Big Data Frameworks: Extensive experience with large-scale data processing frameworks (e.g., Apache Spark, PySpark, AWS EMR, Glue) to handle massive throughput. * Expert SQL & dbt: You design scalable, robust data models (using Jinja, macros, incremental strategies) that serve as the foundation for our entire analytics layer. * AWS Cloud Native & IaC: Hands-on experience building architectures in AWS (e.g.: AWS Lambda, AWS Batch, Glue, StepFunctions, S3, EC2, ECS, ECR, Fargate) and deploying them using Infrastructure as Code (Terraform). * Leadership Skills: Superb organizational and communication skills. You can distill complex architectural trade-offs for non-technical stakeholders and drive technical consensus among your engineering peers. Nice-to-Have Skills: * Polyglot Programming: Experience with a compiled or strongly typed language (e.g., Scala, Go, Kotlin, C++ or Java). * Advanced Orchestration: Experience defining complex dependency graphs in tools like Airflow, Dagster, or Prefect. WHAT YOU WILL DO * Technical Leadership & Architecture: Act as the principal architect for your squad. You will design horizontally scalable, cost-efficient, production-grade data solutions capable of handling TB-scale, highly dimensional datasets. * Engineering Excellence & TDD: Champion rigorous software engineering principles. You will lead the adoption of Test-Driven Development (TDD), CI/CD workflows, and clean code architectures. You ensure our codebase is resilient, testable, and maintainable. * Cross-Squad Impact: Drive technical alignment beyond your immediate team. You will act as an engineering ambassador, solving architectural issues that span multiple squads, keeping our technical processes synchronized, and aligning your squad's work with global engineering priorities. * Domain Mastery: Leverage your deep expertise to build high-value data products on top of location signals and audience attributes. You don't just process data; you deeply understand its geographic and time-series nature to unlock its business value. * Mentorship & Code Quality: Be the technical mentor for Senior, Mid, and Junior engineers. Through highly insightful code reviews, architectural feedback, and pair programming, your input will consistently be the source of others’ learning and growth. * Data Observability: Proactively build monitoring and alerting frameworks at the infrastructure level to catch anomalies in our multi-terabyte data streams before they impact downstream products. WHY US? On top of a competitive package… * We are open to flexible work models: we work on a hybrid mode and remotely  * To encourage education and professional growth, we offer an individual yearly budget of 1.200€ * You are entitled to 30 vacation days per year * We offer Urban Sports Club membership, company pension scheme * Regular team events and company events organised by our People team (Trust us, they know how to throw a party!) * We equip you with the latest hardware and provide you with all the tools you need to thrive SALARY RANGE (ANNUAL ON-TARGET EARNINGS) 90,000 - 100,000 euros RECRUITING PROCESS COULD REQUIRE ON SITE STEPS For technical roles (Data, Engineering, and Product), candidates are encouraged to upload any technical certifications referenced in their CV via the "Other Documents" section of the application form. Alternatively, certification documents may be submitted after the first technical interview. Any certifications listed on the CV must be provided and successfully validated before proceeding to the second technical interview stage. * Step 1: Short 30-min take-home technical quiz. * Step 2: Value-based interview (30 mins). * Step 3: Deep-dive technical interview (1.5 hours) with the Data team. * Step 4: Practical data-crunching challenge. * Step 5: Team Meet & Greet — the final step to ensure we’re a great fit for each other. WORK MODEL Hybrid DESIRED START DATE Asap