Build the modeling engine that powers everything

At Fluxion, the backend is not CRUD.
You’ll build the core computational engine that evaluates, simulates, and reasons over complex graph-based business models.

This role sits at the intersection of:

• Graph theory

• Constraint systems

• Simulation engines

• Performance-critical backend architecture

• Applied mathematics in production systems

We are building infrastructure for reasoning over structured models — not just APIs.

What you’ll do

• Design and implement a graph-based modelling and simulation engine

• Build high-performance evaluation pipelines for scenario analysis

• Develop algorithms for propagating changes across interconnected model nodes

• Handle consistency, determinism, and edge cases in complex constraint systems

• Optimize computation over large, structured datasets

• Integrate AI reasoning into deterministic backend logic

• Make architectural decisions balancing correctness, performance, and scalability

About you

• Have built computationally intensive backend systems (not just REST APIs)

• Are comfortable implementing non-trivial algorithms from scratch

• Have strong foundations in data structures, algorithms, and complexity analysis

• Have worked with graph-based systems, constraint solvers, modelling engines, or simulation frameworks

• Think deeply about correctness, determinism, and failure modes

• Care about performance at the algorithmic level — not just infrastructure scaling

Strong plus signals

• Background in Computer Science, Mathematics, Physics, or similar quantitative field

• Experience with modelling systems (financial modelling, optimisation, simulation, planning systems)

• Experience designing evaluation engines or rule engines

• Experience with distributed consistency or event propagation systems