Samuel Gillespie

Samuel Gillespie

Software Engineer

About Me

Experienced Software Engineer with a strong foundation in modern development practices and cloud technologies. Skilled in designing scalable solutions and collaborating with diverse teams to deliver high-impact software products in the finance sector

Key Skills

  • Python
  • React
  • JavaScript
  • Node.js
  • Docker
  • Kubernetes
  • AWS
  • GraphQL
  • REST
  • Java
  • CI/CD
  • Datadog
Download CV
Experience
Quantitative Analyst at Fitch Ratings
Nov 2018 - Present
Director (2025 - ) / Associate Director (2022 - 2025) / Senior Analyst (2020 - 2022) / Analyst (2018 - 2020)
Primarily specialized in the architecture, implementation, and maintenance of python based modelling by designing and developing a robust, highly distributed, modelling platform utilizing AWS service including EC2, S3, DynamoDB, Lambda and Step Functions. This platform underpins all new model development within the model development team, covering both compute and assumption/data management, and allows for extreme burst capacity and high availability, scaling to thousands of parallel processes, completing days worth of computations in minutes.
Fully instrumented Datadog-based tracking into the modelling platform, enabling comprehensive monitoring, alerting, and performance metrics collection. This integration provides real-time insights into system health and usage patterns, facilitating proactive issue resolution and optimization.
Additionally designed and worked in transitioning legacy Excel and VBA cash flow and asset-based models into Python (Numpy/SciPy/Pandas) with web-based UIs, significantly enhancing efficiency by leveraging the aforementioned modelling platform and allowing programmatic API access to the models.
Optimized model performance through highly distributed parallel processing
Created re-usable python and C# libraries for use within Fitch Rating models e.g. validation modules, API interfaces
Utilized AWS services to develop a large distributed model running platform
Created FastAPI services (REST & GraphQL) for multiple backend systems
Leveraged React to develop web-based interfaces for model and model tools
Facilitated the publication of models to external clients.
Software Design Engineer at Imagination Technologies
Jan 2016 - Jan 2018

Charged with implementing a Git based platform, built on top of Gerrit, to support open sourcing a subset of our driver codebase. Developed an automated system to extract public portions of code as it was deployed, transfer it into a Gerrit change review, and then publish it to a public Git repository. This system was designed to be robust and secure, with a focus on ensuring that no proprietary code was accidentally published.

Also worked on a number of internal tools to improve the efficiency of our development and testing processes. This included a system to automatically (and continuously) run a large suite of tests on an emulated platform using QEMU. Due to the slow nature of the tests this involved a pool of test machines continually rotating through all available tests on the latest codebase.

Designed and implemented software and hardware tools to improve testing and development efficiency.
Researched, designed and implemented an application for review and safe publication of code
Interfaced with various internal departments in order to develop robust operational specifications.
Modified existing software to both fix and upgrade software; working in C, Java, Python and Ruby.
Skills

Python Programming

  • Expert in Python software development
  • Skilled in Pandas, Numpy, SciPy and other similar libraries for financial modelling
  • Developed both functional and object-oriented (OO) projects
  • Knowledgeable in asyncio, threading and multi-processing
  • Created backends with FastAPI, Flask and Django
  • Practised in the development and consumption of REST, GraphQL and RPC based APIs
  • Used pytest to implement unit testing
  • Well versed in AWS libraries integrations with Python
  • Practiced in profiling and optimizing python code for better performance (kernprof, py-spy, cProfile)

General Development

  • Experienced in Javascript, C#, Java, C
  • Highly familiar with AWS developer services: Lambda, EC2, S3, ELB, SFN, SQS, SNS
  • Designed and developed highly distributed micro-service architectures
  • Experienced in CI/CD pipelines (Bamboo, Jenkins, ArgoCD, Github Actions)
  • Knowledgeable in using Docker and Kubernetes for containerization and orchestration
  • Familiar with both Linux and Windows Operating Systems
  • Worked with both SQL (Postgres, MySQL) and NoSQL databases (primarily Redis, DynamoDB and MongoDB)
  • Highly proficient in Git source control management, having used both rebase and merge based workflows
  • Previously AWS Developer Associate Certified

Web Development

  • Knowledge of HTML, CSS, PHP and Javascript
  • Experienced in React and Vue JavaScript frameworks
  • Familiar with RESTful and GraphQL APIs
  • Personally dabbled in Nuxt development for SSR and static site generation
Education

MSc Computer Science

University of Birmingham

Sept 2014 - Sept 2015

Distinction

Modules Included:

  • Neural Computation
  • Databases
  • Artificial Intelligence
  • Data Structures
  • OS and Networks
  • HCI

Summer Project:

Development of a neural network poker AI, capable of playing Limit Texas Hold'em

BA (Hons) Physics

University of Oxford

Sept 2011 - Sept 2014

2:2

Modules Included:

  • Flows, Fluctuations & Complexity
  • Quantum, Atomic & Molecular Physics
  • Thermal Physics
  • Astrophysics
  • Sub-Atomic Physics
  • Condensed-Matter
  • Electromagnetism
  • Optics
  • Mathematical Methods

Group Industrial Project:

Developed and created, as a team of 6, an apparatus capable of measuring thermal conductivity at liquid nitrogen temperatures (-200°C). This project received the Gibbs Prize for Best Group Project Presentation.

A-Levels & GCSEs

Parmiter's School, Hertfordshire

Sept 2004 - June 2011

A-Levels

  • Physics: A*
  • Mathematics: A
  • Further Mathematics: A*
  • Systems and Controls: A

GCSEs:

13 GCSEs at grade A or A* including Maths and English

Gold Crest Award:

Participated in the Engineering Education Scheme, completing (as a team of 4) a real life 6 month STEM project in Year 12