Senior Full-Stack Software Engineer (AI / ML)

About Nyxium

Nyxium is a London-based deep tech company backed by top-tier investors. We are building an agentic AI and geospatial intelligence platform that supports siting, permitting, impact assessment, and decision-making for complex infrastructure projects, including energy systems, data centers, and other critical infrastructure.

Location

London

Right to work in the UK required (visa sponsorship considered on a case-by-case basis)

Time Commitment & Working Arrangement

This is a full-time position (40 hours per week).

The role requires focused, dedicated commitment to Nyxium.

• External paid work, consulting, or freelance engagements outside Nyxium are not permitted during employment.
• Any academic affiliations, advisory roles, or unpaid activities must be disclosed and must not conflict with Nyxium’s work, priorities, or intellectual property.
• We value sustainable working practices and do not expect routine overtime, but we do expect full professional focus during agreed working hours.

Role Summary

We are hiring a Senior Full-Stack Software Engineer (AI / ML) to build and own Nyxium’s core application and ML integration layer.

This role sits between:

• AI and ML systems (LLMs, NLP pipelines, decision logic)
• Backend services and APIs
• Data and document workflows
• User-facing analytical and operational tooling

You will work directly with the founders and the Geospatial AI Engineer to turn advanced AI and spatial intelligence into robust, production-grade software that real teams depend on.

This is a senior individual contributor role with strong architectural ownership.

Key Responsibilities

AI-Enabled Backend Systems

• Design and build backend services that integrate AI and ML workflows into production systems
• Develop APIs and orchestration layers
• Ensure AI outputs are traceable, explainable, and suitable for audit and regulatory review
• Develop Retrieval-Augmented Generation (RAG) and LLM-based pipelines for data imputation, NLP analysis, and decision support.

Document, Workflow & Platform Intelligence

• Build systems that process, normalize, classify, and enrich large volumes of structured and unstructured documents
• Implement intelligent workflows for:
• Regulatory documentation
• Compliance evidence tracking
• Developer and user automation
• Design pipelines that balance ML-driven inference with deterministic rules and safeguards

Full-Stack Application Development

• Build and maintain user-facing applications that expose complex AI outputs in clear, actionable ways
• Implement interactive dashboards, workflow UIs, and operational tools
• Collaborate on frontend architecture using modern frameworks (React / Next.js), with a focus on correctness and clarity rather than visual novelty

Data & API Engineering

• Design schemas and APIs for systems that combine:
• ML outputs
• Geospatial attributes
• Regulatory and temporal data
• Work with Postgres (PostGIS a plus), MongoDB, and analytical data stores
• Build reliable async processing, background jobs, and batch pipelines

Production Quality & Developer Experience

• Improve system reliability, testing coverage, and observability
• Contribute to CI/CD pipelines and deployment workflows
• Raise internal standards for code quality, documentation, and maintainability
• Build systems that other engineers and stakeholders can confidently rely on

Collaboration & Ownership

• Work closely with founders on roadmap execution and technical trade-offs
• Collaborate daily with the Geospatial AI Engineer to integrate spatial intelligence into the platform
• Take full ownership of major system components from design through deployment
• Contribute to technical decision-making as the platform scales

Required Qualifications

Education

• Bachelor’s or master’s degree in computer science, Data Science, Engineering, or a closely related field
• Equivalent industry experience considered

Core Technical Skills

Programming & Backend

• Strong Python experience in production systems
• Experience with FastAPI, Flask, or similar frameworks
• Experience building ML-backed APIs and services

AI / ML Integration

• Hands-on experience integrating ML or LLM systems into real applications
• Familiarity with NLP pipelines, document processing, or AI workflows
• Understanding of model lifecycle concerns such as versioning, latency, and reliability

Data & Platforms

• Experience with SQL and NoSQL databases
• Schema design for complex, evolving data models
• Experience with background jobs, async workflows, and data pipelines

Frontend (Applied)

• Working knowledge of React and modern frontend patterns

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• Experience building dashboards or analytical user interfaces

Cloud & Tooling

• Experience deploying systems on AWS and/or GCP
• Familiarity with Docker, CI/CD, and production monitoring

Experience

• 5+ years of professional experience in software engineering, data engineering, or ML-enabled systems
• 5+ years of experience in geospatial analytics, applied ML and computer vision, including production systems
• Demonstrated experience delivering end-to-end ML solutions in complex, real-world environments
• Proven experience shipping production systems used by real users
• Comfortable operating in early-stage or high-ownership environments

Preferred / Nice-to-Have

• Experience with geospatial data or spatial platforms
• Experience in environmental, infrastructure, healthcare, or regulated domains
• Experience building internal tools, developer platforms, or workflow automation systems
• Background in developer experience or platform engineering

What Success Looks Like

• You ship reliable, production-grade systems that form the backbone of the platform
• AI and ML capabilities are usable, trustworthy, and well-integrated
• Developers and users experience clear, stable workflows instead of brittle tools
• You raise the overall engineering bar through thoughtful system design and execution

Compensation

Salary and equity

• We offer above market, competitive salary and meaningful equity.
• Final offer depends on experience and scope of responsibility.

Benefits

• Flexible, remote-first working arrangement
• Pension contributions (UK auto-enrolment)
• Paid annual leave and UK public holidays
• Direct access to founders and real influence over technical direction
• Opportunity to work on high-impact, technically challenging problems from the ground up

Why Join Us

• You will build core systems, not surface features
• Your work will directly shape a category-defining platform
• You will operate in a small, senior, high-trust technical team
• You will work on problems that matter in real regulatory and infrastructure contexts