Featured build
Live
Job Hunt Pipeline
A daily AI job search that screens LinkedIn roles against my rules and resume.
- C#
- .NET 10
- Claude Code
Senior Software Engineer · C#/.NET · Backend + Full Stack
Jessica Haynes
I build reliable software for messy, real-world problems.
I have 9+ years of experience building and modernizing production applications, with deep experience in C#/.NET, APIs, architecture, performance, and technical leadership. I use AI as part of a disciplined engineering process, from requirements and design through implementation, testing, and review.
Featured Projects
Featured build
In Development
PokéJudge AI
An AI rules assistant that asks the right questions before it recommends a cited ruling.
- C#
- .NET
- RAG / Retrieval
Featured build
In Development
Loot Singles Fulfillment
A set-aware picking app built to prevent wrong-card mistakes and order collisions.
- React
- TypeScript
- C#
Featured build
V1 Complete
RoleSync
A Shopify app that ties member discounts to verified Discord roles.
- TypeScript
- React Router
- Shopify API
Featured build
Live
pricewatch
A Go CLI that prices an 8,800-card collection on 1,000 API requests a day.
- Go
- SQLite
- GitHub Actions
Experience
- Programmer
- Senior Developer, promoted
- Senior Developer
- Lead Developer
- Senior III
- Team Lead / Senior IV, promoted
8am
Austin, TX / Remote
Team Lead / Senior Software Engineer IV
Jan 2024 – Present
- Led a cross-functional team of 4, driving a quality-focused culture shift that achieved 6+ months of incident-free production and a 50% drop in support escalations
- Spearheaded the team's adoption of agentic AI coding tools (Claude Code, GitHub Copilot), improving engineering efficiency and TDD adoption
- Improved onboarding for QA and developers by overhauling documentation and establishing clearer project standards
Promoted
Senior Software Engineer III
Mar 2022 – Jan 2024
- Optimized a high-volume nightly job, cutting runtime by 95%
- Implemented Single Sign-On (SSO) for the payment processor, integrating with clients' existing identity providers to streamline authentication
.NETC#MySQLEntity FrameworkAngular
Lead Developer, Proplanner.net
Jan 2020 – Mar 2022
Ames, IA
- Designed and supported an Identity and Access Management service, configuring SAML/OIDC connections for all clients
- Led a team that reduced security vulnerabilities by 81% across all applications
- Engaged directly with clients to gather feature requirements and resolve deployment issues
C#.NET CoreSAMLOIDC
Earlier roles (3)2016 – 2020
Senior Software Engineer (Team Lead), Growers Edge
Feb 2019 – Jan 2020
West Des Moines, IA
- Served as technical lead across multiple projects, owning design and delivery
- Trained and mentored junior engineers in programming methodologies and best practices
- Collaborated with product owners to proactively identify risks and recommend alternative technical solutions
.NET CoreAngular 7Azure
Proplanner.net
Ames, IA
Senior Software Developer
Dec 2017 – Feb 2019
- Increased the client base by 200% by leading a platform modernization initiative
- Prioritized and assigned tasks to a small team of developers
- Decreased time spent on support by creating a program to help automate the build process
Promoted
Programmer
May 2016 – Dec 2017
- Built and maintained features for a .NET Windows desktop application, including third-party integrations and rapid resolution of critical issues
.NETASP.NET Web APIAngular 4+
About
I'm a senior software engineer who builds and modernizes full-stack enterprise applications, mostly C#/.NET backends, APIs and Entity Framework, with MySQL, Angular and TypeScript alongside. I've led technical projects, mentored engineers, written technical designs, and worked closely with Product, QA and DevOps.
I try to bring curiosity to my work, keep learning, and leave things better than I found them.
How I work
Problem-Solving & Collaboration
I like understanding the problem I'm solving, asking questions when something doesn't make sense, and working with the people around me to find a good solution. When I notice the same problem coming up or something making work harder than it needs to be, I work on fixing it.
Staying Current
I enjoy learning new technologies, evaluating how I work, and adopting tools and approaches that improve my development process. Recently, I've been exploring how AI-assisted development can help me work more efficiently while maintaining the technical understanding and engineering judgment needed to deliver reliable software.
Learning now
I'm learning how to use AI more effectively in my engineering work. That includes building better agent workflows, checking how systems behave, and deciding where people need to stay involved in automated processes.
- Agentic engineering workflows
- AI evaluation & reliability
- Human-in-the-loop product design
Psst, there's a Pokémon mode.
Let's Connect
If you're hiring, have a project in mind, or want to talk shop, I'd love to hear from you.