Senior Software Engineer · 15+ years of Ruby · regulated fintech at scale
At Tembo Money I work across the architecture, observability, AI, and reliability of an FCA-regulated mortgage platform — ~1.7M requests and 500K+ background jobs a day across 8 services.
I build systems that earn their complexity through evidence, not fashion — and I write about how. The same conviction runs through my day job, my books, and the engines I build from scratch.
- Built a unified case-management tool that collapsed the 22 separate systems a broker juggled per applicant into a single workflow — cutting the time and complexity of each case from ~65 minutes to about 10, and built to double mortgage capacity without added headcount.
- Shipped AI bank-statement analysis on AWS Bedrock (income & risk signals from PDF statements), and contributed the Bedrock provider upstream to the ActiveAgent open-source project.
- Stood up platform observability from scratch — six NewRelic dashboards including the board-level OKR instrument — and cut the deploy pipeline from ~2 hours to 35 minutes.
📘 Modular Rails: Architecture for the Long Game — building maintainable Rails applications with Rails Engines and modular monoliths. Amazon UK · Amazon US. The book's patterns, executable: Seams — a CLI that scaffolds a Rails app into real engines (with companion app Orbit).
📗 Building Your Own Roguelike: A Practical Guide — procedural generation, ECS, and event-driven design, built from scratch in Ruby.
Extreme Programming by default — TDD, pairing, continuous integration, simple design. Modular monoliths over premature microservices. Architecture decisions backed by evidence, not trend.
- Seams — a CLI that scaffolds Rails apps into modular engines: the Modular Rails thesis as runnable tooling.
- Vanilla Roguelike — a pure-Ruby roguelike with procedural generation and an ECS core.
- DS Laboratory — a one-person studio building games on an owned, zero-dependency, deterministic engine. Reference game: Filed Under No One. - free, in your browser.
- 🌐 davidslv.uk — blog, books, portfolio
- 𝕏 @davidslv