About the Company

At Avaron, you get the security of permanent employment combined with the variety of working at different customers. We place specialists across everything from tech, IT and industry to project management and business support – and whatever the assignment, you have a consultant manager who is there for you and your development.

About the Role

You will join a backend team working on an API that delivers static and market data for financial instruments in a modern banking environment. The solution supports an investment app today and is designed to serve more retail channels over time, which means your work will sit close to both business value and end-user experience.

This is a role for you if you enjoy solving search-heavy backend challenges where performance really matters. OpenSearch is a central part of the platform, used not only for storage but as a search and ranking engine for finding, filtering, sorting and ranking instruments across multiple dimensions with high speed and low latency.

You will also work with the ingestion flow behind the API, where data from several external sources is collected, normalized and made ready for reliable use downstream. The focus is on building services that are trusted in production, shaped by customer needs and released continuously.

What makes this role especially interesting is the chance to influence a product where search quality, data accuracy and backend design directly support better investment decisions.

Job Description

• You will build and improve backend APIs in Node.js and TypeScript for serving instrument and market data in production.
• You will design, tune and evolve OpenSearch-based search and ranking capabilities, including indexing strategy, complex queries, aggregations and performance optimization.
• You will develop data ingestion pipelines that combine, reconcile and normalize data from multiple external sources.
• You will work closely with the team to understand customer needs and turn them into solutions that create clear value.
• You will use TDD to shape code and system design, from unit tests to end-to-end flows with test containers that mirror live environments.
• You will contribute to a delivery setup with daily releases, where reliable CI outputs and production-ready quality are essential.

Requirements

• Extensive hands-on experience and deep knowledge of OpenSearch or Elasticsearch, especially as a search and ranking engine rather than only as storage.
• Strong practical knowledge of indexing strategy, advanced query design, aggregations, multi-dimensional sorting and ranking, and performance tuning for low-latency workloads at scale.
• Solid hands-on experience with Node.js and TypeScript for building production APIs.
• Experience building data ingestion pipelines that combine and reconcile data from several external sources.
• Experience working with TDD in backend development, including automated tests across different levels.
• A strong interest in building solutions based on customer value and close collaboration within the team.

Nice to have

• Experience self-hosting and operating OpenSearch or Elasticsearch clusters.
• Interest in, or experience with, financial instruments, markets, key figures and financial analysis.
• Experience working in an agile way.

What We Offer

• Permanent employment at Avaron AB
• Occupational pension
• Wellness allowance of SEK 5,000 per year

Application

Selections are made on an ongoing basis – apply as soon as you can.