Curriculum Vitae

Jacob Halsey. Bristol, UK

Email: jacob@jhalsey.com
Website: https://www.jhalsey.com/
LinkedIn: https://www.linkedin.com/in/jacob-halsey/
GitHub: https://github.com/jacob-pro

Personal Statement

I am currently a senior software engineer working on Oracle Cloud’s API Gateway, which is a large scale production service deployed in over 100 data centres. I have an in-depth knowledge of computer systems and networks, and experience with a number of different programming languages. I have a strong attention to detail, with a focus on producing clean and simple software abstractions. In particular, I am interested in modern systems languages like Rust that can ensure memory and concurrency safety without compromising performance. and have made a number of contributions to open source Rust projects.

Skills

Programming in Java, Rust, C, Python, Lua, Objective-C, Swift, PHP, Go, Typescript & Javascript.
Experience with concurrent programming and building distributed systems.
Automated testing; unit testing, integration testing, CI pipelines.
Strong knowledge of the HTTP/1.1, HTTP/2.0, and WebSockets protocols, modern authentication systems (JWT, OAuth 2.0, OIDC, mTLS).
Provisioning infrastructure with Terraform, packaging with Docker, maintaining Linux and Windows systems.
Databases: key-value stores including Redis, SQL including Oracle, Postgres, MySQL.
Experience with operations and maintenance, structured logging, telemetry, zero downtime deployments, and on-call incident response.

Experience

Senior Software Engineer - Oracle: 2023 - Present

As part of the API Gateway team, I make substantial contributions to a cloud service that is processing over 20 billion HTTP requests per week, with particular focus on the core data plane proxy application.

Key achievements:

Development of graceful shutdown functionality, with full observability of interrupted HTTP requests.
Substantial contributor to a successful rewrite and modernisation of our data plane proxy server from NGINX/Lua to Jetty/Java. This included the HTTP request body processing logic, in-memory loading caches, logging, and authentication modules.
Replacement of password based Redis authentication with a fully automated mTLS solution.

Software Engineer - Oracle: 2021 - 2023

Major contributions to the Usage Plans feature. I wrote the cloud controllers that synchronise control-plane and data-plane state (Java), developed the public console pages or subscriber management (React/Typescript), and built automated end-to-end tests for the whole feature (Java).
Extensive experience managing and automating highly available Redis clusters; developed an automation for rack-zone awareness, set up a compact cluster mode that required fewer CPU cores, and developed an automated process for zero-downtime cluster migration between X86 and ARM shapes. Changes led to significant cost savings, operations and reliability improvements.
Drove efforts to improve team processes, including development of a new integration test suite, introducing templating engines for internal documentation, improvement of CI pipelines with type checking and linting.

Software Development Internship – Oracle: Summer 2019

Developed an internal tool used for auditing cloud resources (Java, Docker).
Developed the per-request metrics reporter in the API Gateway data plane (NGINX/Lua).
Developed scheduled business metrics (Java), with a Grafana dashboard used by management to monitor feature usage.

Software Developer – Createanet: 2017 – 2018

Developed 6 iOS apps (Objective-C, Swift), one of these apps was a social media platform, others were for photo and video sharing, electronic forms / paperless, consumer rewards, and video conferencing.
Developed REST APIs and administration websites to power the apps (PHP/MySQL).

Education

Undergraduate

University of Bristol: 2018 - 2021
BSc Computer Science: First Class Honours

A Level

Churston Grammar School: 2015 – 2017
Computer Science: A*, Maths: A*, Further Maths: A, Economics: A, Physics (AS): A

Westlands School: 2013 – 2015
BTEC Level 3 Diploma in IT: Distinction* Distinction*

Certifications

Cisco CCNA Routing and Switching: 2016 – 2019
Topics included IPv4/6, TCP/UDP, Ethernet (VLANs, STP, security), static and dynamic routing.