Senior Backend Engineer
Foundational backend work at a venture-backed fintech SaaS in Manhattan. You'll build the calculation engine, workflow orchestration platform and financial models that every feature of the product sits on, working directly with the founders. Platform engineering rather than feature work, in an environment where correctness, auditability and clean abstractions are the whole job.
The work
Some engineering teams build features. This one builds the foundations every feature sits on. You'll join a small group responsible for the calculation engine, workflow orchestration platform and financial modelling systems that power the entire product. One day you might be extending a custom expression language that lets users define complex business calculations without writing code. The next, you're designing workflow engines that coordinate stateful processes across multiple systems, or modelling how money moves through highly configurable financial structures where every calculation must be explainable, auditable and correct. You'll work across language design, data modelling, workflow orchestration, financial logic and distributed systems without being siloed into one area, alongside founders, product leaders and domain experts who care about engineering quality and thoughtful system design.
What you'll be doing
Most of your time goes on hard modelling problems, not moving tickets between columns. Three core systems sit at the centre of the platform:
- Extending a configurable calculation engine with new functions, execution capabilities and developer tooling
- Designing and building workflow orchestration systems that coordinate complex multi-step processes
- Translating complex business and financial processes into configurable, reusable software models
What you'll need
Ideally you've also worked early-stage, where engineers are expected to own architecture decisions, and you can explain complicated technical ideas clearly to engineers and non-engineers alike.
- Six to twelve years building backend systems, with complex projects led from design through to production
- Experience on platforms where correctness, auditability and reliability matter deeply: financial systems, billing engines, trading platforms, accounting systems or infrastructure tooling
- You've designed configurable systems: rule engines, workflow platforms, formula engines, DSLs or other user-programmable abstractions
What happens next
CV review, an introductory call, technical discussions, an architecture and systems design conversation, then time with the founders. We start with a confidential discussion and share the full company overview before anything moves forward.
If it is a fit, you will get a straight read on the process and the comp. If it is not, I will tell you that too.