Software Engineer jobs in United Kingdom

London, UK

Symbolica is an AI research lab pioneering the application of category theory to enable logical reasoning in machines. We’re a well-resourced, nimble team of experts on a mission to bridge the gap between theoretical mathematics and cutting-edge technologies, creating symbolic reasoning models that think like humans – precise, logical, and interpretable. While others focus on scaling data-hungry neural networks, we’re building AI that understands the structures of thought, not just patterns in data.

Our approach combines rigorous research with fast-paced, results-driven execution. We’re reimagining the very foundations of intelligence while simultaneously developing product-focused machine learning models in a tight feedback loop, where research fuels application.

Founded in 2022, we’ve raised over $30M from leading Silicon Valley investors, including Khosla Ventures, General Catalyst, Abstract Ventures, and Day One Ventures, to push the boundaries of applying formal mathematics and logic to machine learning.

Our vision is to create AI systems that transform industries, empowering machines to solve humanity’s most complex challenges with precision and insight. Join us to redefine the future of AI by turning groundbreaking ideas into reality.

We’re looking for a Python Software Engineer to take full ownership of building and shipping the core systems that power Symbolica’s applied AI products. This is a true generalist role: you’ll work across our SDK, developer libraries, server-side platform, integrations with inference providers, and applied AI features such as agent engineering, per-model optimizations, and context tuning.

Your work will directly shape the developer and user experience — from designing clean APIs and libraries that customers use every day, to building the backend systems and integrations that make it all reliable at scale. You’ll be the bridge between research prototypes and production-quality systems, helping turn cutting-edge ideas into tools that developers love.

📍 This is an onsite role based in our London office (66 City Rd).

• Build, maintain, and improve Python-based systems across the stack: SDK, libraries, APIs, server-side platform, and integration layers.
• Work on applied AI engineering, including per-model optimisations, context tuning, and agent-related features.
• Design developer-facing tools and libraries that customers can use directly.
• Integrate with external inference providers to ensure reliability and scalability.
• Own projects end-to-end: clarify requirements, design, implement, test, and ship production-ready code.
• Collaborate with ML researchers and engineers to turn prototypes into robust, usable systems.
• Contribute to architecture discussions, code reviews, and best practices for building maintainable software.
• Continuously improve developer experience and system performance.

• 4+ years of professional software engineering experience, with Python as your primary language.
• Strong track record of delivering production-quality systems end-to-end.
• Proven ability to work from incomplete specs and drive projects to completion.
• High standards for code quality, testing, maintainability, and performance.
• Experience with ML infrastructure, applied AI systems, or developer tooling is a big plus.
• Thrive in fast-moving, ambiguous environments where priorities shift quickly.
• Ownership mindset: you see what needs doing and take responsibility for delivery.

• Competitive salary and early-stage equity package
• A high-trust, execution-first culture with minimal bureaucracy
• Direct ownership of meaningful projects with real business impact
• A rare opportunity to sit at the interface between deep research and real-world productisation

Symbolica is an equal opportunities employer. We celebrate diversity and are committed to creating an inclusive environment for all employees, regardless of race, gender, age, religion, disability, or sexual orientation.

We are able to sponsor a Skilled Worker visa for qualified candidates applying to this position. This role exceeds the minimum salary threshold set by the UK government for Skilled Worker visa sponsorship. English language proficiency at B2 level or higher is required for this role.