Senior Software Engineer Python in Didcot

My client is looking for a Senior Software Engineer Backend Leaning Contract may also be considered.

What You Will Be Doing

You'll sit at the core of their product, building the systems that make advanced AI usable in the real world. If you enjoy owning backend services end to end, care deeply about reliability and API quality in a high-impact environment, this role offers both autonomy and real impact.

Requirements

• Backend Architecture & APIs (Primary Focus)
• Design and evolve scalable backend services in Python using FastAPI for high-availability, high-throughput workloads.
• Build well-versioned RESTful APIs aligned to OpenAPI/Swagger, with strong conventions for consistency, idempotency, and backward compatibility.
• Implement authentication and authorization using OAuth2/OIDC, session management, and fine-grained permissions.
• Design and maintain event-driven architectures and background processing pipelines (e.g. Celery, Redis Streams, Kafka) to enable scalable async workloads, retries, and fault-tolerant integrations.
• Design data models and optimise relational databases (PostgreSQL) for performance, partitioning, and horizontal scale.
• Introduce caching, rate limiting, and queuing to meet performance budgets and latency goals.
• Integrate with AI pipelines and model-serving endpoints, including streaming responses, async inference jobs, and robust error/retry semantics.
• Palantir Foundry Integration
• Work with Palantir Foundry to build and maintain data pipelines, ontologies, and integrations that connect backend services to Foundry-based analytics and workflows.
• Leverage Foundry's APIs and tooling to support data modelling, transformation, and secure data exchange across the platform.
• Security & Reliability
• Write secure, well-tested code (unit, integration, end-to-end) and uphold coding standards through code reviews.
• Contribute to logging, metrics, and alerting (Prometheus/Grafana, ELK/OpenSearch) for the services you build.
• Support compliance readiness (ISO 27001, GDPR) through secure-by-default design.
• Cross-Functional & Process
• Collaborate closely with the engineering team, product and leadership to scope, sequence, and deliver outcomes.
• Translate product requirements into technical plans, breaking work into milestones with measurable success criteria.
• Mentor engineers on backend design and API ergonomics.
• Infrastructure Contributions (optional)
• Ship services via Docker containers with clean, minimal builds.
• Contribute to IaC (Terraform/CloudFormation) and CI/CD pipelines (GitHub Actions/Argo CD) alongside the DevOps team.
• Support cloud operations with sensible defaults, cost awareness, and environment promotion across dev/staging/prod.

Required Skills & Experience

• SC Clearance or the ability to obtain SC (and later DV).
• 5+ years of professional software engineering experience, with a strong focus on backend development in Python and with event-driven architectures.
• Proven experience designing and operating production REST APIs with OpenAPI/Swagger.
• Deep understanding of relational database design, indexing, performance tuning, and migrations (PostgreSQL).
• Proficiency with containerisation (Docker) and Git-based workflows.
• Experience with API versioning, security, documentation strategies, and automated testing.
• Strong problem-solving skills and the ability to work independently with high ownership.

Soft Skills

• High-agency engineer who owns outcomes end to end.
• Pragmatic, research-driven approach with a bias to ship and iterate.
• Clear communicator who can talk to stakeholders of varying technical backgrounds.
• Comfortable defining SLAs, making trade-offs explicit, and operating production systems.

Benefits include:

• Rapid career progression and personal growth
• Flexible working hours
• 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 + public holidays