Backend & Infrastructure Engineer
Summary
Backend & infrastructure engineer at a B2B climate-tech startup building physics-based simulations for commercial battery storage and renewable energy projects.
About the Role
This is a backend and infrastructure engineering role at an early-stage B2B SaaS company in the commercial battery storage and renewable energy space. The platform runs physics-based simulations that help installers, wholesalers, and distributors size, plan, and sell large-scale battery projects — replacing manual spreadsheet work with precise, data-driven proposals covering peak shaving, arbitrage, grid services, and more.
Each simulation compares hundreds of battery configurations across multiple application scenarios, producing millions of data points per run. Compute demand is growing on three axes simultaneously: more users, higher usage per user, and increasingly complex simulations. The company is operating in a market doubling year-over-year, with customers across six European countries — and the goal is to scale the customer base by at least 100x.
You will be the owner of the entire backend and infrastructure. This is a high-autonomy, high-ownership role at a company that moves fast, minimises meetings, and makes real architectural decisions.
What You'll Do
Own and evolve the full backend and infrastructure stack end-to-end.
Ensure service reliability, security hardening, and robust monitoring across all production systems.
Scale compute-heavy simulation workloads to support a rapidly growing user base.
Design and implement backend architecture for high-throughput, numerically intensive applications.
Manage containers, orchestration, queues, and cost control as the system scales.
Optimise performance and compute costs continuously, balancing engineering correctness with shipping speed.
Make and own architectural decisions — including whether the current Python-based engine should be rewritten in another language.
Support new product features and new types of battery application scenarios as the product roadmap expands.
What We're Looking For
Required:
5+ years of experience owning and scaling production backend systems under real-world load.
Hands-on experience with web application infrastructure scaling: containers, orchestration, queues, monitoring, performance optimisation, and cost control.
Proficiency in Python, or a strong willingness to work in Python while driving architectural decisions (including potential rewrites).
Experience designing backend architectures for compute-heavy, numerically intensive applications.
Proven ability to work independently, own projects end-to-end, and make sound architectural decisions with incomplete information.
Experience with service reliability, security, and production monitoring.
Comfort with the pace and ambiguity of an early-stage startup environment.
Fully integrated use of AI tools in your development workflow — with the ability to debug and reason independently when needed.
Nice to Have:
Experience with physics simulations or numerical computing workloads.
Background in energy markets, electrical engineering, or energy management systems.
Compensation & Benefits
Base salary: €110,000 – €150,000 per year
Equity: 0.5–2.5%, standard 4-year vesting with a 1-year cliff
Location
Based in Berlin, Germany. On-site or hybrid working arrangements are available. This role is not fully remote.