Senior Software Engineer

Role: Senior Software Engineer

Contract: Permanent

Salary: 80-110K

Location: Greater Oxford Area (Harwell, Didcot)

Working Pattern: Flexible & Hybrid

Security clearance: You must be eligible for UK security clearance (BPSS and SC). We require applicants to hold UK passport and at least 5 years of continuous UK residency. If you are not eligible, we will not be able to progress your application.

A note from the Founders

Oxford Dynamics is at an inflection point.

We build frontier AI for environments where the cost of a wrong decision is high: defence and national security, critical infrastructure, and commercial organisations making high-stakes decisions on complex data. We are growing fast, and the constraint on how fast is no longer ideas or opportunity. It is whether the systems we ship are good enough for the people who stake decisions on them.

That is where you come in. We need engineers who can build the systems this mission depends on, and build them to a standard that holds when the answer has to be right. You will be trusted to own real systems end-to-end, held to a single high standard, and judged on one thing above all: whether what you ship earns the confidence people place in it when the decision matters.

If you are the kind of engineer who builds rather than assembles, who wants your work measured by whether it holds up in production rather than whether it demos well, and who wants to see the direct line from your code to systems people depend on, we would love to hear from you.

Who We Are

Founded in 2019, Oxford Dynamics is a fast-growing UK frontier technology company developing both digital and physical AI systems built to operate in dynamic, mission-critical environments.

At the core of everything we build is AVIS™ (A Very Intelligent System), our orchestration platform: the intelligence layer that fuses multi-modal data, including text, imagery, telemetry and sensor feeds, so operators can interrogate complex information at speed and make better decisions under pressure. AVIS™ powers our digital decision products, such as ORION for multi-source decision-to-effect, and it powers our physical platforms.

We work where wrong decisions can be catastrophic. We partner with defence, security and private sector organisations internationally to bring frontier AI into the environments where it matters most, whether that is protecting nations, infrastructure and lives, or transforming how commercial organisations reason over their data and make high-stakes decisions.

Requirements

About the role

This is a senior individual-contributor role with room to grow into staff-level scope. You will own significant parts of our platform end to end - design, build, ship, operate, and you will shape how the wider engineering team works: the architecture we converge on, the standards we hold, and the engineers we grow.

We care more about depth of engineering judgment than about any particular stack. Most of our backend is Python, our data lives in PostgreSQL, and everything ships in containers but if you have built serious systems elsewhere and want to work in this stack, we would still like to hear from you.

What you will be doing

Systems and architecture (primary focus)

· Design, build and evolve backend services for high-availability, high-throughput workloads - currently Python and FastAPI, though the principles matter more than the framework.

· Own the design of well-versioned HTTP APIs: clear contracts, consistency, idempotency, backward compatibility, and documentation people can actually use.

· Design event-driven systems and background processing pipelines (queues, streams, workers) that handle retries, partial failure and back-pressure gracefully.

· Model data properly and tune the databases behind it - schema design, indexing, query performance, migrations, and scaling strategy.

· Apply caching, rate limiting and queuing to hit explicit performance and latency budgets.

· Integrate with AI pipelines and model-serving endpoints, including streaming responses, async inference jobs, and sane error and retry semantics.

· Take on the ambiguous problems: the ones where the requirement is a paragraph, the constraints conflict, and someone needs to decide.

Security and reliability

· Package and ship every service as a clean, minimal Docker container, with reproducible builds and sensible runtime defaults.

· Write secure, well-tested code - unit, integration and end-to-end, and raise the bar for others through code review.

· Implement authentication and authorisation (OAuth2/OIDC), session management and fine-grained permissions.

· Build in observability from the start: structured logging, metrics, tracing and alerting for the services you own.

· Support compliance readiness (ISO 27001, GDPR) through secure-by-default design rather than retrofitted controls.

· Take part in operating what we build - you should be comfortable being close to production.

Technical leadership

· Translate product intent into technical plans: milestones, sequencing, measurable success criteria, and honest estimates.

· Make trade-offs explicit and write them down, so the team can disagree with the reasoning rather than the conclusion.

· Mentor engineers on system design, API ergonomics and operational thinking; grow the people around you.

· Communicate clearly with stakeholders of varying technical background, including non-engineers and customers.

Infrastructure (welcome, not required)

· Contribute to infrastructure as code (Terraform/CloudFormation) and CI/CD (GitHub Actions/Argo CD) alongside the DevOps team.

· Support cloud operations with sensible defaults, cost awareness, and clean promotion across dev/staging/prod.

Requirements

Essential

· Strong hands-on experience with Docker and containerised deployment - building images, debugging containers, and running containerised services in production.

· Strong programming ability in Python, or demonstrable depth in a comparable language with a willingness to work primarily in Python.

· A track record of building and operating production backend systems at a level where you set the design, not just implemented it.

· Proven experience designing and operating production APIs - versioning, security, documentation and automated testing.

· Solid grounding in relational database design, indexing, performance tuning and migrations (PostgreSQL or equivalent).

· Experience with asynchronous or event-driven architectures and the failure modes that come with them.

· Fluency with Git-based workflows and code review as a team practice.

Nice to have

· Experience integrating with AI/ML systems or model-serving infrastructure.

· Exposure to enterprise data platforms (for example Palantir Foundry, Databricks or Snowflake).

· Observability tooling (Prometheus/Grafana, ELK/OpenSearch).

· Container orchestration (Kubernetes, ECS) and infrastructure as code.

· Experience in regulated, safety-critical or security-cleared environments.

· Prior experience as a technical lead, or as the senior engineer on a small team.

How you work

· High agency - you own outcomes end to end and pull on threads without being asked.

· Pragmatic and research-driven, with a bias to ship and iterate.

· A clear communicator, in writing as much as in conversation.

· Comfortable defining SLAs, making trade-offs explicit and operating production systems.

Benefits

Why Oxford Dynamics?

Join one of the most exciting growth areas in the UK: AI and robotics. Every member of the team has a major impact on the products and services we provide. Regardless of job title, you will make a real difference and learn from colleagues across the whole business.

Benefits include:

· Rapid career progression and personal growth

· Flexible working hours

· The opportunity to shape the future of a fast-growing business

· Hybrid working model

· Company pension (NEST) with 4% employer contribution

· Private healthcare

· 29 days holiday plus public holidays

Oxford Dynamics is committed to creating an inclusive team experience for all. Regardless of race, gender, religion, sexual orientation, age, disability or parental status, we believe our work is at its best when everyone feels free to be their authentic self.