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Senior Backend Engineer (f/m/x)

RemoteBerlin, Berlin, GermanyTech - Backend

Job description

About lemon.markets 🍋

We're on a mission to open 100 million brokerage accounts within the next ten years. Building the infrastructure for FinTech companies to launch an investing feature or product in Europe. Delivering the full value chain of brokerage through one API.

Over the last few quarters we focused on bringing the first version of the API to the market. Thousands of developers signed up and hundreds started to build their individual use cases with us. This resulted in 80+ inquiries from companies to launch their own stock trading UI with lemon.markets. With 15 million of fresh funding, we are now taking the next steps toward our mission: Building out our capabilities to allow (Fin)Tech companies to offer investment opportunities to their customers.

We have experienced first hand that brokerage infrastructure is broken. It’s a messy and complex problem that will take time to solve. But that’s exactly what we enjoy. Going to places nobody else dares and shielding our customers from the biggest pain. This not only creates tons of value when done right, but attracts the smartest minds - because we believe outlier companies are built by exceptional people like you.


Your Mission:

At lemon.markets we offer you the opportunity to build our Brokerage API from the ground up. As Senior Backend Engineer you will play a key role in designing the backend services and architecture of our brokerage API that will allow other companies to easily embed investing into their product. You will take ownership of features and services ensuring they run smoothly on production, while collaborating closely with the product team, Infrastructure, and DevOps engineers.

Your main objective will be to build our flagship product - the Brokerage API - from scratch. Joining our compact & dedicated team of Backend and Infrastructure Engineers, you will have a significant impact on the development of our Brokerage API - and thereby architectural decisions as well as on the business itself - from the first lines of code to the product’s launch and beyond.


You will:

  • You have the ability to write well-structured and tested code in several high-level programming languages like Python, Javascript, Typescript or Go.
  • You have excellent knowledge & experience around web frameworks, preferably FastAPI; alternatively, you have experience with Flask, Sanic, Tornado, or Falcon.
  • You have proven experience designing and implementing highly scalable architecture and reliable REST APIs and bring the desire to make them world-class.
  • You’ve gained good experience with AWS Services such as EC2, EKS, S3, RDS, or Athena
  • You have a good understanding of open source databases such as PostgreSQL or memory-databases like Redis; experience with time series databases like QuestDB is beneficial but not a must.
  • You know your way around API Gateways - experience with Kong gives you a head start.
  • You have good understanding and experience with streaming or messaging platforms, ideally Kafka
  • You gained hands-on experience with testing different entities, use-cases, and 3rd party integrations - preferably writing tests with pytest
  • You have a solid understanding of distributed systems
  • You have excellent problem-solving skills and the ability to provide in-depth evaluations and analyses of unique and complex technological issues

Job requirements


You will be successful in this role if:

  • Growing investment opportunities excites you. We operate in a highly regulated environment and therefore having worked prior in a Fintech or financial Service provider (Bank, Insurance or Brokerage) would give you a head start, but is not a must.
  • You enjoy building from scratch. This means high involvement in the product development process itself while advocating for the best engineering practices. It also means that you enjoy taking technical decisions.
  • You have a bias for action over a discussion. To avoid getting stuck in a discussion, you collect new feedback, try out a different approach or gather data with a proof of concept because you trust the process.
  • You are ready and willing to take ownership of problems and act on them decisively with no supervision. You always thrive for high quality outcomes through focus, determination and attention to detail.
  • You are a team player. Working together as a team and sharing knowledge comes naturally to you. Long term - you consider becoming a team lead.
  • You have no problem with learning new technologies on the go. You try to solve problems with more things than the ones you already know. We will always enable you with that, but your willingness has to come first.
  • You understand what working in a startup or a similar lean organisation is like. Working in an early-stage startup can be somehow frightening, overwhelming, and amazing at the same time.


We're looking for people with passion, desire to learn and that are team players. You're encouraged to apply even if your experience doesn't precisely match the job description. Your skills and passion will stand out & set you apart—especially if your career has taken some extraordinary twists and turns. lemon.markets welcomes people from all different backgrounds, including age, citizenship, ethnic and racial origins, gender identities, individuals with disabilities, marital status, religions and ideologies, and sexual orientations to apply.


How we take care of you:

🚀Competitive compensation package:

We will offer you a mix of cash and stock options based on your appetite for upside.

💎Make a real impact:

Shape the experience for our customers and us alike. Decide on tools, processes and the architecture design of our API, while building, learning and growing together.

🕑Flexible working hours:

We value focus time. Encouraging everyone to minimise fixed meetings and leverage asynchronous communication.

💻Build your perfect setup:

Mac/Linux, Mechanical Keyboard, Screen. These are not expenses but investments. Please tell us what is needed to make you productive, and we will take care of it.

🏢 Onsite first, but remote flexible:

We all believe that in - person collaboration is an integral part of working together, but offer flexibility for remote working. Once a quarter the whole team meets for our offsite to honer this belief. In case you want to relocate to Berlin, we can provide assistance and visa sponsorship.

📈 Grow with us:

We take your personal development seriously, meaning that we make sure to constantly mentor and challenge you so that you can reach your next level and beyond.

👶🏽 Get the flexibility you need:

Whether you have a family or a passion that you want to follow on the side. We want to offer you a setting that fits your current stage in life.

About the process

Hiring can be an exhausting process, especially when you're the one trying to get hired. Therefore, we try to make this a fast and transparent process. Additionally, you will always have one contact person guiding you through the process and helping you to schedule meetings, and setting you up on a path of success. Your process will look like this:

  1. Get to know us - Talent - Jasmin | 40 minutes

  2. Technical Interview - Engineering Team - Dennis & Pawel | 90 minutes

  3. Meet us @ lemon.markets HQ | 120 minutes

    1. Get to know - Sam - VP of Engineering | 60 minutes

    2. Meet the Founder - Max | 30 minutes chat

    3. Meet the team  | 30 minutes chat


4. Problem Deep-Dive: Task - Discussion | 45 minutes