Steve Stagg

Contract lead developer

Email: [email protected]
Mobile: (+44)7868 129642


Contracts - Bank of America,, Cmed, BskyB 2013 - current
  • Developed a system that transformed Tier-1 investment bank’s transaction reporting from being a significant regulatory risk, to being awarded most accurate high-volume transaction reporting firm by Unavista in 2018.
  • Real-time MiFID II post-trade & transaction reporting engine using python and numpy. Generating millions of daily reports from tens of millions of events, joining multiple external datasets and running thousands of rules. Average report published in 80ms. One-click auditable per-field lineage documentation generated by static analysis of rules.
  • Designed and implemented a full-stack system for self-service machine learning anomaly detection, based on streaming datasets. Working with ML expert to build intuitive, guided interface designed to be used by non-technical SMEs. Using scipy, sklearn, pandas, parquet, d3 and ag-grid. Detected systemic issues in upstream systems causing significant data quality issues.
  • Wrote highly optimized Cython Avro serialization library & recursive Python JIT to enable use of python at required throughputs.
  • Revolutionized problem analysis in the department by implementing novel UI for visualising trade lifecycles, exposing complex timing based issues in an easy-to-discover interface.
  • Brought in to troubleshoot and performance tune problematic Objective-C IOS app. In two days was able to deliver 5x performance gain in primary bottleneck. Delivered design plan for larger architecture improvements.
  • Worked in a variety of agile & scrum teams, from one to 15 members
Tech Lead (Head of Backend) - onefinestay 2017
  • Successfully led complete rewrite of website backend. Handling 3x inventory, with real-time feeds from external systems, using graphql. Results: improved performance, reduction in operational issues & support. Project delivered in two-month deadline
  • Implemented novel flask based graphql interface using runtime automatic schema generation using type hinting. Advanced Postgresql based pricing calculation removed need for slow, high-maintenance search indexes.
  • Managed geographically distributed backend engineering team
Software Engineer - Cmed Technology 2008 - 2012
  • Technical lead and engineer for an integration project that formed the nexus of a pivotal eSource trial that gained recognition from Microsoft, the FDA, SCDM, and the board of a top-tier Pharma company
  • Tech lead & Architecture for Django based web UI frontend. Replacing existing flagship UI. Handling clinical trial data, from scratch. Produced Design & Functional specifications that passed MHRA audit.
  • Product Management for major project, providing mockups, design specs and technical guidance to dev teams.
Web Development - Contract 2005 - 2008
  • Bespoke web site design. Web service and filtering technologies developed in PHP, C and C++.
  • Custom message-filter based MS Exchange email keyword scanning in C++ using Regex and Aho-corasick.


I try not to focus too much on particular technologies. Other factors typically are more important than which language or library is chosen. However my experiences tend to center around: