Back End Developer (Mid-level)

What are we looking for?
A talented Backend developer with a track record in Python! You'll be part of a small team dedicated to developing our web application Canopy; building the APIs, data access, and services that turn millions of raw sensor readings and machine learning results into something our users can actually act on. You will be working together tightly with the product team led by one of the founders and a solid machine learning & devops engineering team to build product technology that is already creating an impact on a global scale.
We are pragmatic: expect to be writing our code on day one and shipping in your first week.
Who we are
Jungle develops and applies Artificial Intelligence to increase the uptime and performance of renewable energy systems. Our technology builds on existing sensors and data streams, and enables solar and wind energy owners to squeeze more out of their machines, accelerating the world's transition to renewable energy sources.
We have productised our services into a web application named Canopy. It's helping users across a portfolio of several gigawatts of installed capacity, to get more energy production out of their machines. We operate at large scale - millions of data points per day - providing always-on predictive models, alarms and metrics visualisations for some of the largest and most sophisticated customers in the global renewable energy space.
Why do we need you?
Canopy's frontend is only as good as what we can serve it. Our users ask for years of time series data, filtered and aggregated on the fly, next to model outputs and results from complex data pipelines. That means endpoints that stay fast under real load, queries that stay fast as the data grows, and a clear head about what should be done now, in the background, or not at all. We have tons of ideas and are looking to increase the team to make these a reality.
Day-to-day activities
Build and extend the backend behind Canopy.
Design and tune the data access layer: schema changes, indexes, and queries that hold up against large time-series tables in Postgres.
Take part in collaborative problem solving and architecture discussions with your team members. We care about our code base and treat it well!
Maturing and simplifying our codebase, and preparing it for an accelerating growth. Focussing on standardised, modular and robust implementation of reusable services and functionality.
Interface and align with the Platform team on technical scope, decisions, and implications as a lot of what the backend serves originates with them.
Research new (upcoming) technologies that will considerably improve the performance of our product or the development time of our team.
Code reviews and helping peer developers grow technically in their role.
Why work with us?
At Jungle, you are accelerating the energy transition to renewable sources; arguably the most important challenge of our generation.
You will learn and explore new technologies through your work on features and services.
You will be assigned a personal mentor to help you develop professionally.
As part of a small and experienced team, you will enjoy freedom in your work and be involved in all areas of our product.
We measure performance, not hours. You will have a flexible work schedule, holiday policy, and work location.
The role is fully remote. We meet twice a year in Portugal for a week of work, fun, and team activities.
Modern work environment, tools and peripherals.
Become part of a warm and skilled group of people.
Requirements
3+ years of professional experience building Backends in python. Computer Science degree (BSc) and 3 years of professional experience building backends in Python. Alternatively, without a Computer Science degree, we require 4 years of professional Python backend experience. During this time, you have contributed to core parts of the code base.
Solid experience with Flask or FastAPI (FastAPI preferred). You know how a request actually travels through the framework, not just how to add a route.
Strong SQL and hands-on experience with Postgres. You can read a query plan, spot the missing index, and explain why your rewrite is faster.
Comfortable with Docker — you can build, run and debug your own services locally.
A working understanding of async and sync in Python: what blocks an event loop, when concurrency actually buys you something, and when it just buys you bugs.
You think before you type, and consider the impact of the code you are writing. You are able to think in terms of latency, memory, and how things will behave once used by many people and machines simultaneously.
[bonus] Experience with time-series data at scale.
[bonus] Experience with background/task processing (queues, workers, scheduled jobs).
[bonus] Experience running services in production: observability, profiling, incident debugging.
About you
You're pragmatic; you know when to trade off diving deep with quick fixes.
You have a natural tendency to want to get to the bottom of things.
You are curious and won't stop searching and asking questions until you find the answer.
Practical details
Full-time, fully remote. With at least a few hours of overlap with Lisbon/Portugal timezone. Please let us know your location and timezone when you apply.
Strong English fluency.

Work arrangement
Yes