ThoughtRiver is a pioneering legal technology company solving a key challenge for lawyers and in-house legal teams: knowing whether a contract needs attention without reading it end-to-end. Its AI-powered contract pre-screening platform uses advanced Natural Language Processing (NLP) and legal intelligence to analyse agreements and deliver clear, actionable recommendations in minutes.

At the core of the platform is Lexible, a universal contract description framework built from thousands of real-world legal questions. Developed in collaboration with Cambridge University, it maps obligations and rights within any agreement, helping lawyers understand risks and priorities instantly. ThoughtRiver's 97%accuracy score is far superior to the main LLMs on the market, which score around 76%.

ThoughtRiver partners with in-house teams, general counsels, and law firms globally, enabling them to review contracts faster, unlock new revenue streams, and focus on higher-value legal work.

We are seeking a Backend Python Software Engineer to help build, scale, and optimise the backend services that power ThoughtRiver’s AI-driven legal platform. This is a hands-on engineering role where you will design and implement event-driven services, APIs, and integrations that connect our AI models with enterprise clients worldwide.

 You’ll collaborate closely with AI engineers, product managers, QA, and our legal experts to deliver secure, scalable, and performant systems that underpin the next generation of contract intelligence.

• Design, build, and maintain Python-based backend  services that connect AI models, data pipelines, and user-facing applications.
• Develop and optimise RESTful APIs and  microservices running in a cloud-native (Azure) environment.
• Collaborate with AI and platform engineers to integrate LLM outputs into production-grade services.
• Implement testing frameworks, CI/CD pipelines, and monitoring tools to ensure reliability and uptime.
• Contribute to architecture decisions around scalability, security, and future-proofing the platform.
• Work closely with product teams to translate legal workflows into robust technical implementations.

• 3+ years of professional experience as a Backend or Software Engineer with Python as your primary language.
• Proven expertise in event-driven services, REST APIs, and microservice design.
• Strong grounding in databases (SQL and NoSQL), data modelling, and API integrations.
• Experience with CI/CD pipelines (GitHub Actions, Azure DevOps, or similar).
• Familiarity with containerisation (Docker) and cloud deployments (Azure or AWS).
• Strong problem-solving skills and ability to work in a fast-paced startup culture.

• Experience integrating AI/ML pipelines or APIs into backend systems.
• Knowledge of Kubernetes (AKS) and infrastructure-as-code (Terraform).
• Exposure to observability tools (Prometheus, Grafana, OpenTelemetry).
• Experience in SaaS, legal-tech, or other regulated industries.

• Impact at scale – shape the backend systems powering a category-leading AI platform.
• Cutting-edge environment – collaborate at the frontier of AI, SaaS, and cloud-native engineering.
• Career growth – upcoming funding will double engineering headcount, offering progression and leadership opportunities.
• Benefits – private healthcare (for you + dependents under 18), 25 days holiday + birthday + bank holidays, rising with tenure, 4% pension match, and equity participation.

1. 30-minute virtual call with COO (fit & high-level experience)
2. 60-minute technical interview with CTO (system design & Python deep dive)
3. Final stage: practical coding exercise and team session