Backend Software Engineer (Fintech / Barcelona)

Flanks; Vilanova y Geltrú; Hybrid; EUR 35,000 - 50,000; Full time

Benefits offered by this job

Full-time contract

Salary €35k–€50k gross per year

Hybrid work in Barcelona

Birthday off

Health insurance

Training budget

Office in Barcelona

Kombo 50% digital canteen

Team events

Job summary

Flanks is a fintech startup in Barcelona redefining wealth management data handling. We seek a Mid-Level Backend Engineer to design, build, and optimize data pipelines and backend services that enable reliable data-driven decisions across the organization.

You will own end-to-end data ingestion and transformation, write high-performance Python/JS code, and collaborate on SQL/NoSQL database design while practicing CI/CD and Docker-based deployments. English and Spanish skills are required.

Qualifications

• Proficient in Python and/or JavaScript with performance and production-grade focus.
• Experience building and operating data pipelines (ETL/ELT) and backend services for a product, with exposure to Elasticsearch.
• Familiarity with SQL and NoSQL databases, schema design, and query optimization.
• Ability to work autonomously and drive scope to production from high-level requirements.
• Willingness to learn financial data context and implement related formulas.
• Professional proficiency in English and Spanish for bilingual collaboration.

Responsibilities

• Design, develop, and maintain scalable ETL/ELT pipelines to ingest, transform, and load data from multiple sources into core systems.
• Write clean, efficient Python code with a focus on performance and memory efficiency.
• Collaborate on database schema design (SQL and NoSQL) and optimize query performance.
• Implement unit tests, integration tests, and data quality checks to ensure pipeline integrity.
• Deploy and iterate on pipelines using CI/CD and containerization with Docker.

Skills

Python

JavaScript

SQL

NoSQL

CI/CD

Tools

Docker

Elasticsearch

Job 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 2019 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 see

• 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.

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 offer

• A 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 process

1. You'll have a chat with our People Business Partner, Nicolás Guilarte.

2. A meeting with the Tech Team.

3. A technical test.

4. Final interview to review the technical test and iron out any remaining questions.

5. 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.