9fin is a rapidly scaling company that powers global debt markets with its AI platform. We're looking for a Senior Software Engineer to join our team and work on Elasticsearch cluster and its configuration. The role involves maintaining the search infrastructure, collaborating with a senior team of engineers, and contributing to the development and engineering of the 9fin platform.
Requirements
- Experience operating as a Senior IC Engineer, leading systems design and infrastructure discussions, mentoring more junior team members, and scoping work within cross-functional product teams.
- Deep understanding of Elasticsearch internals (inverted index, shards/replicas, segment merging, refresh/flush cycles) and how they impact performance and consistency.
- Strong experience designing and tuning mappings, analyzers, and tokenizers for precise search relevance.
- Proven ability to optimize query performance (DSL queries, filters vs queries, aggregations, caching, profiling, avoiding expensive operations like script queries when possible).
- Hands-on experience operating clusters in production (index lifecycle management, shard allocation, scaling, monitoring, failure recovery, snapshot/restore).
- Solid knowledge of distributed systems concepts (consistency, partitioning, replication, eventual consistency) and how Elasticsearch behaves under load and failure scenarios.
- Plan and reason about software effectively, clearly and compellingly communicating its purpose within systems and its business impact on clients.
- Hands-on experience designing data flow through software, from persistent storage to API endpoints, while applying industry best practices for validation.
- Experience with Python and its web frameworks (we currently use FastAPI with strong typing & Pydantic).
- Strong experience delivering APIs, Service Oriented Architecture.
- Strong working knowledge of SQL statements for retrieving data.
- Good collaborator and communicator with cross functional engineering teammates and others within 9fin.
- Code Quality: Through writing testable, maintainable code, and by engaging in code review for your own work and for reviewing others.
Benefits
- Competitive Salary (our salary bands are benchmarked at the top end of the market)
- Equity options
- Pension (your minimum contributions are 4% with 9fin matching up to 7%)
- Private Medical Insurance
- Paid sick leave with Income Protection for long periods of illness
- Group Life Assurance
- Season Ticket Loan & Cycle to Work schemes
- 25 holiday days per year
- Local public holidays (with the ability to exchange them for alternative days)
- Hybrid working model, to allow you the flexibility to decide how, where and when you do your best work
- Work abroad for up to 3 months a year
- 1 month paid sabbatical after 5 years of service
- Enhanced parental leave & flexible working arrangements available
- Professional learning and development budget
- Quarterly team socials
- Summer and Winter company social events
