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# Backend Software Engineer

- **Company:** Flanks
- **Location:** Madrid, Spain
- **Salary:** €35,000.0 - €50,000.0
- **Contract:** Permanent contract
- **Skills:** Query Performance, JavaScript (Programming Language), Unit Testing, Big Data, Software as a Service, Code Review, Continuous Integration, Data Validation, Extract Transform Load (ETL), Data Security, Data Structures, Database Schema, Elasticsearch, Python (Programming Language), NoSQL, Query Optimization, SQL Databases, Data Ingestion, Backend, Containerization, Integration Tests, Production Code, Data Pipelines, Docker
- **Published:** September 7, 2026
- **Apply:** https://www.buscojobs.com.es/backend-software-engineer-en-madrid-ID-370335637

## About the Role

Strong Python and/or JavaScript engineering skills, with a focus on performance, memory efficiency, and writing maintainable, production-grade code.
Solid experience building and operating data pipelines - ETL/ELT patterns, pipeline orchestration, and handling large-scale data ingestion - or experience building backend services for a product, ideally with exposure to Elasticsearch.
Familiarity with both SQL and NoSQL databases, including schema design and query optimization.
Comfort working autonomously - able to take a high-level requirement, define scope, and drive it to production without heavy hand-holding.
Ability to navigate unfamiliar codebases quickly and contribute meaningfully from an early stage.
Experience with CI/CD workflows and containerization (Docker or similar).
Willingness to understand the financial data we work with and the formulas you will be responsible for implementing.
It is important to be curious and open to learning how financial markets work, as this context is essential to correctly ingest, process, and expose financial data.
Language Proficiency: Professional proficiency in both English and Spanish to collaborate effectively in our bilingual environment.

## Description

A little bit about Flanks Flanks is shaking up the wealth management industry by making it simpler and way more efficient for financial institutions.Our SaaS platform is designed to help banks, family offices, and wealth managers get a full picture of their clients' financial assets-all in one place.Founded in **** and based in Barcelona, we've brought together a team of passionate wealth management and tech pros, all with a shared goal: to change how wealth management is done.Backed by €23 million in investment, we're growing fast, and we're not stopping anytime soon!What we stand for:People First - our team comes first.We want every Flanker to feel at home, engaged, and part of something bigger.Keep Growing - as the company grows, so should you.We're all about personal and professional development here.Think Twice, Act Once - we believe in thoughtful decisions, considering the impact on both our team and our clients before taking action.If you're looking for a place where you can grow and make an impact at a fast-paced, exciting fintech startup, this might just be the place for you!About the role As a Mid-Level Backend Engineer on our Tech Team, you will design, build, and optimize the data pipelines and backend services that keep clean, reliable data flowing across the entire organization.You will own the full lifecycle of data ingestion and transformation work - from understanding a business requirement through to production deployment - and directly shape the backend infrastructure that powers our data-driven decision-making at Flanks.What you'll do Here's what you can expect to work on:Design, develop, and maintain scalable ETL/ELT pipelines to ingest, transform, and load data from multiple disparate sources into our core systems.Write clean, efficient Python code with a strong focus on performance - applying optimal data structures and algorithms to handle high-volume datasets reliably.Collaborate on database schema design (SQL and NoSQL) and own query performance optimization to ensure fast, accurate data access.Implement unit tests, integration tests, and data quality checks to guarantee pipeline integrity and catch issues before they reach production.Deploy and iterate on pipelines using CI/CD practices and containerization tools such as Docker, participating actively in code reviews to uphold team standards.What we'd love to seeStrong Python and/or JavaScript engineering skills, with a focus on performance, memory efficiency, and writing maintainable, production-grade code.Solid experience building and operating data pipelines - ETL/ELT patterns, pipeline orchestration, and handling large-scale data ingestion - or experience building backend services for a product, ideally with exposure to Elasticsearch.Familiarity with both SQL and NoSQL databases, including schema design and query optimization.Comfort working autonomously - able to take a high-level requirement, define scope, and drive it to production without heavy hand-holding.Ability to navigate unfamiliar codebases quickly and contribute meaningfully from an early stage.Experience with CI/CD workflows and containerization (Docker or similar).Willingness to understand the financial data we work with and the formulas you will be responsible for implementing.It is important to be curious and open to learning how financial markets work, as this context is essential to correctly ingest, process, and expose financial data.Language Proficiency: Professional proficiency in both English and Spanish to collaborate effectively in our bilingual environment.If this sounds like you, don't worry if you don't check every single box-we'll support your growth along the way.What we offerA full-time, permanent contract.A salary range of €35,000 - €50,000 gross per year, based on experience.A cool office between Sants Estació and Plaça Espanya with stunning views of Barcelona.Flexible working hours and hybrid work options.Paid day off on your birthday.Weekly fresh fruit, coffee, and tea on tap.Friday happy hours after our all-hands meetings (totally optional, of course!).Team-building events to bond and have fun.Health insurance and flexible compensation with Alan.A digital canteen, thanks to Kombo, subsidised at 50%.A yearly training budget to keep growing.The hiring processYou'll have a chat with our People Business Partner, Nicolás Guilarte.A meeting with the Tech Team.A technical test.Final interview to review the technical test and iron out any remaining questions.We send you an offer!We aim to keep things moving fast-ideally wrapping things up in one to four weeks.At Flanks, we believe in fostering diversity and inclusion across everything we do.We're proud to be an equal opportunity employer, and we welcome all applications regardless of race, religion, gender, age, or disability status.Additionally, we have an Equality Plan in place to ensure fairness and inclusivity in all our policies and practices.#J-*****-Ljbffr


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