Senior Core Technologies Engineer

Fin is the AI Customer Agent company on a mission to help businesses provide perfect customer experiences.

We are looking for a Senior Engineer to join the team that enables the core technologies that Fin is built on.

What will I be doing?

• Own high-impact work on Elasticsearch at scale, including index design, shard and partitioning strategy, cluster health, performance tuning, safe migrations, and operational excellence.
• Collaborate with world-class domain experts to shape our technical direction and infrastructure as we grow.
• Deeply own aspects of our infrastructure at Fin and autonomously executing on high impact projects - including writing application code, automating systems, improving observability and low-level tuning of datastores used in production, test and development across Fin.
• Value agility and simplicity, just as you prioritise scalability and uptime.
• Contribute to all phases of software development including ideation, prototyping, design and implementation.
• Play an active role in the hiring, mentoring, and career development of other engineers.
• Raise the bar for technical standards, performance, reliability, and operational excellence across Fin.

What skills do I need?

• Excellent pragmatic engineering skills.
• 5+ years experience in a production environment, with contributions to the design and architecture of distributed systems.
• Strong experience with at least one major production datastore or search system, with Elasticsearch being especially relevant for this role.
• Good judgment around Elasticsearch in real-world systems, such as index and mapping design, cluster operations, scaling patterns, performance tuning, or migrations.
• Expertise in backend technologies such as MySQL, Memcached, as well as Linux.
• Ideally, you’ve supported scaling a SaaS product in a previous role and loved the satisfaction that comes with knowing that people around the world are using something you’ve created.
• Significant, demonstrated impact that your work has had on the product and/or the teams you worked with.
• Proficient with standard software engineering methodologies, e.g. unit testing, object-oriented design, data structures, code reviews, design documentation, and utilising observability tooling.
• Understanding of modern web apps and distributed systems, along with an ability to articulate technical challenges and solutions.
• Experience as a technical lead for large multi quarter projects and programs including defining the roadmap.
• Ability to learn quickly, iterate, unblock yourself, and persist until the right problem is solved.

Benefits

We are a well treated bunch, with awesome benefits!

• Competitive salary and equity in a fast-growing start-up
• We serve lunch every weekday, plus a variety of snack foods and a fully stocked kitchen
• Regular compensation reviews - we reward great work!
• Unlimited access to Claude Code and best-in-class AI tools; experimentation & building is encouraged & celebrated.
• Pension scheme & match up to 4%
• Peace of mind with life assurance, as well as comprehensive health and dental insurance for you and your dependents
• Flexible paid time off policy
• Paid maternity leave, as well as 6 weeks paternity leave for fathers, to let you spend valuable time with your loved ones
• If you’re cycling, we’ve got you covered on the Cycle-to-Work Scheme. With secure bike storage too
• MacBooks are our standard, but we also offer Windows for certain roles when needed.