Oferta sólo disponible en Inglés
Oferta cerrada el 13/11/2023

Senior JAVA Developer

🎯 Product🚀 Scale-Up🕐 Flexible schedule🌎 International team👛 Stock Options

Sparta is revolutionising the commodity trading industry with a B2B SAAS that does away with the Excel that all traders have been working with for decades.

They have an unbeatable feedback and recurring revenue. They are growing and have already found one of their backend, but we are still looking for someone to complement the backend team and bring a little more seniority, ¡GO!

Are you a backend and want to know more? Read on :)

¿Qué harás?

We are in front of one of those unicorns that emerge at the perfect moment. 🦄

Before we talk about the present moment, let's look back at the problems that the tool they have created in Sparta has come to solve, Come on!

The energy market is on the rise. Sparta’s adventure began in 2019 when Felipe (CEO) and Miles (COO) decided to leave the world of oil trading, with more than 35 years of experience behind them. They realised that the wave of digitalisation and new technologies had not yet reached the commodities trading market. With the collaboration of Luis (CPO) they jumped into the pool and decided to set up Sparta, with a clear vision of automating, optimising and increasing the productivity of commodity traders.

Traders’ value is defined by their ability to make decisions (good ones), and the best way to do so is to base them on reliable quality data. Sparta comes in to revolutionise the industry, not only aggregating the most relevant information, but also processing it and enabling traders to communicate with their teams quickly and efficiently in the cloud. In the process, they allow trading firms to create their own databases with the most relevant information, so they can learn from previous experiences.

At the end of 2020 they launched their MVP on web and iOS and since then the product has grown at a dizzying pace. 2023 has been an amazing year with multiple new product launches completed and planned, rapid growth of their client base and ARR, and further significant financial backing from venture investors expected in Q3 to help accelerate their growth even faster. There are over 65 people shaping their premium products, providing maximum value to their users with each feature.

At Sparta, they want you to helping all dimensions of the project. Your feedback will be very welcome. They will rely on your experience to decide the best way to implement or solve tasks.

The person they are looking for is someone who will bring their experience to the table, is hungry, and will help them continue to grow. You will be a valuable member of the teamou will help colleagues to grow and the team to proactively look for solutions - do not be afraid to do something they haven't done before!

Their technology stack is split into three:

  1. third-party data processing on AWS Lambdas using python
  2. A monolith built with Kotlin Spring deployed on AWS.
  3. And new endpoints developed on NodeJS microservices using Serverless.

In 2023, they are splitting the monolith into microservices written in any of the technologies they have. 

If you want to be part of the Sparta team, you will face challenges around horizontal scaling, multi-region deployment and real-time data processing.

Tu evolución

Tu primer día

En 1 mes

This month will be about landing in the team, getting to know the people and getting used to the 100% remote way of working (if you had no previous experience). They want you to have a voice and expect you to give feedback on the way they do things from day one, and help them iterate on all aspects of the organisation. 

You'll be assigned an onboarding buddy when you arrive, and you'll start getting to know everyone. 

From this point on you'll be soaking up the project, pair programming with your colleagues, and you'll have a lot of documentation to help you put the pieces in place :)

Tus responsabilidades

  • You will be part of the design and development of new technical solutions with your team, as well as overseeing those of other team projects.

  • You will review your colleagues' code, proposing improvements to software practices and repo infrastructure.

  • During sprints, you will launch new features and products. Make sure that you include necessary automated tests. These tests, will be validated by the QA team and monitored with the help of the DevOps team.

¿Cómo lo harás?

The technical team is made up of multidisciplinary squads where backenders, frontenders, a QA, a Lead, a Product Manager and a Team Manager work hand in hand focused on different parts of the product and the data team. Everyone has a voice and decision-making power, so when the team decides something, it gets done.

The company has formed a team of stakeholders called Commodity Owners who have the market expertise. Together with the product team are in charge of designing what the users expect. Most of the application requirements will come through them. But they know that most of the time, the star features and happy ideas come from the technical team, so they will always be available to receive new ideas and discuss them with you.

But you may wonder... What is the team workflow like? Read on :)

The product team does the planning and defines the features, setting them out in a PRD with all the details. With this definition, the technical team studies it and sees the implications that the development of each feature will entail, and reflects it in a technical definition document. 

From this moment on, these features will enter the refinement process, where the tickets are generated.  Those tickets will be estimated at the beginning of each Sprint, based on the team’s working pace, and the priorities that the product team has decided.

The sprints in Sparta last two weeks. At the end of each sprint, they do a review meeting to show what has been implemented to the rest of the group and a Retro to evolve as a team. As there are two teams, once a month, this retro includes all the squads.

¿Cuándo trabajarás?

At Sparta, they really do enjoy flexible hours, and all they ask is that all team members are available during a certain time slot so that you can coordinate (you know, daily meetings to discuss decisions...).

These meetings are currently held in the middle of the day, so that whether you're an early riser or someone who needs 5 coffees to completely wake up, it's not a problem. The important thing at Sparta are the goals :)

Día laborable

Jornada completa


23 días

Jornada laboral


¿Dónde trabajarás?



Sparta was born 100% REMOTE. Felipe is based in Geneva, Miles in London and Luis in Basel.

The development team is spread between Spain and the UK, so they strongly believe in the benefits of remote working and work-life balance.

However, you will have a budget, so you can work from a co-working space if you wish.

On top of that, teams often meet physically throughout the year to discuss issues that are easier to define in person, or to focus a bit on the medium and long term vision. In addition to these team meetings, an annual company-wide meeting is organised. In October is the third one and they will organise it again in Mallorca where people from all corners of the world will attend!

¿Con quién trabajarás?

The team is well-balanced, experienced and well-oiled ♥️.

Sparta is made up of a team of 60 people. More than 30 people are part of the product team :)

  • Felipe Elink (CEO) - Has more than 15 years of experience in oil trading, particularly petrols and biofuels in BP and Gunvor (the fourth-largest oil trading company in the world). He's Spanish, married and has three children.
  • Miles Moseley (COO) - Has 20 years of experience in petrol trading at BP. He's English, married and has two children.
  • Luis Ibáñez (CPO) - Has spent ten years working as a programmer and another five managing development teams. He has worked in Spain, London and Switzerland. His latest venture was with Roche Pharmaceuticals. He has twice built teams from scratch and his ideas for keeping team members happy involve doing everything he expected to be done when he was a programmer.
  • Paul Laight (CTO) - He has 20 years of experience building highly complex products, platforms, companies and teams within the FinTech space.
  • Javier López (Staff Data Engineer) - Javi is a born leader. With almost ten years of experience as a programmer in backend, machine learning and big data, he is key to the evolution of Sparta's product as well as to the medium-and long-term vision of the team.
  • Paco Estévez (Staff Engineer) - Ex-Facebook, Ex-New Relic and super Spartan! Paco is a generalist engineer with a focus on Developer Experience. A great coordinator, mentor and technical manager, Paco is in charge of leading the technical team and planning the medium and long term of the technological part.

Among them, there are some real manfredites... And more coming soon 😉.

¿Qué piden?

Sparta's stack revolves around JAVA and some Python, Kotlin and TypeScript, with a strong emphasis on optimising communications and data processing. So what are you looking for?

  • Responsibility for the delivery and maintenance of projects from inception.
  • Experience working with Java11+ on the backend or in mobile
  • Experience with real-time systems, i.e. websockets, stock tickers, games...
  • Knowledge of distributed computing such as map/reduce operations in the cloud
  • Fluent written and spoken English.

And it would be a plus if:

  • In your career you may have known other backend technologies such as Typescript, Python or Scala.
  • You have worked with Spring and Hibernate.
  • Knowledge of AWS services like Fargate, API Gateway or Lambda
  • Knowledge of SQL with Postgres, MySQL or similar
  • NoSQL with DynamoDB, Mongo or similar
  • Queue maintenance and distributed event buses such as Kafka or Amazon Kinesis



  • Java
  • AWS

Estaría bien

  • Spring
  • Hibernate

Suma puntos

  • NodeJS
  • Kafka
  • SQL
  • Kotlin

Otras habilidades


  • Capacidad de autogestión
  • Trabajo en equipo
  • Proactividad
  • Pensamiento analítico

Estaría bien

  • Adaptabilidad al cambio
  • Capacidad de dar feedback
  • Comunicación intercultural

¿Qué ofrecen?







⏰ Flexible working hours, although they want to coincide with the rest of the team for four working hours.

🏥 Medical and dental insurance on a reimbursement basis.

💵 You will receive a share of the company's equity.

🏖️ 23 days holiday.

And also... 👀👇


Clases de Idiomas
Presupuesto para formación
Presupuesto para Conferencias
Seguro de salud
Dinámicas y eventos de teambuilding
Presupuesto para coworking
Posibilidad de elegir equipo

What the FAQ?

As good Galicians, we have to say... It depends XD

For administrative reasons, they can manage recruitments in Spain, UK and Switzerland.

NO. The team is spread over locations from Córdoba to London, from Valencia to Basel.

They organise occasional face-to-face events lasting a couple of days and hope that you'll want to attend. Of course, they'll cover the cost of these trips :)

  1. There'll be an initial meeting with the CTO so you can get to know each other.
  2. The second phase is a pair programming with the technical team based on a challenge that will be sent to you (not very long!).
  3. A final meeting with the CEO and COO :)