Senior Software Engineer

Bryan DeLeon

Building reliable systems, one clean commit at a time.

About Me View Resume
GitHub · LinkedIn

About

Not your typical engineer.

Before writing code professionally, I spent years on Chicago's trading floors building pricing models and managing risk in high-stakes, real-time environments. That chapter taught me things no CS curriculum covers: how to stay calm under pressure, build things that actually have to work, and know when to raise your hand.

I eventually went back for an M.S. in Computer Science at UChicago, and since then I've built backend systems across healthcare, data infrastructure, and e-commerce. I care about clean architecture, high test coverage, and actually shipping things on time.

I work best as part of a team. I ask questions, take feedback seriously, and try to leave things better than I found them.

0+ Years of experience
MIT B.S. Management Science
UChicago M.S. Computer Science
AWS Certified Cloud Engineer

Expertise

What I work with

BE

Backend Engineering

Python, Django, Flask, REST APIs. I've built services that need to be fast, testable, and maintainable under real production load.

PythonDjangoFlaskJava
CL

Cloud & Infrastructure

AWS-certified with hands-on experience across ECS, Lambda, CodePipeline, CloudFormation, and Redshift.

AWSDockerKubernetesTerraform
CI

CI/CD & DevOps

I build and maintain pipelines that deploy reliably across development, staging, and production environments.

CodePipelineCloudFormationChef
DA

Data & ETL

From MSSQL migrations to Redshift optimization, I've worked with data at scale and know how to make queries perform.

SQLRedshiftPySparkETL
Mo

Mobile Development

Built iOS applications using Objective-C and Swift, including biometric authentication flows with voice and fingerprint verification.

SwiftObjective-CiOS
FE

Financial Engineering

Years of experience building pricing models and trading algorithms that ran in live, automated market environments.

MATLABC#Quantitative Models

Career

Where I've worked

Sunday

Senior Back-end Engineer

Nov 2022 – Present Boulder, CO / Remote
  • Owned and executed a large-scale architectural refactor to decouple the core cart system, reducing technical debt and preserving critical business logic while coordinating across the engineering team with minimal oversight.
  • Designed and built a store credit service integrated across purchase order confirmation, subscription reauthorization flows, and tax recalculation.
  • Diagnosed and resolved a series of critical issues in the flex pay installment system — including auth-fail recovery flows, subscription state remediation, and store credit application across multi-payment sequences.
  • Redesigned the Stripe integration to improve scalability and add Apple Pay and Google Pay support.
  • Built proactive health monitoring alerts for out-of-stock inventory, overdue subscriptions, and cart anomalies — surfacing issues before they reached production.
  • Maintained and extended integrations with Avalara (tax), Klaviyo (email), Segment (analytics), UPS (shipping), and Amazon (soil test acquisition channel).
  • Managed recurring Django LTS upgrades, keeping the platform current with each new long-term support release.
PythonDjangoAWSStripeAvalaraSegmentKlaviyo

Wayspring

Senior Software Engineer

Mar 2018 – Nov 2022 Nashville, TN / Remote
  • Architected and maintained end-to-end CI/CD pipelines across development, staging, and production environments using AWS CodePipeline, CloudFormation, and ECS.
  • Designed and delivered multiple production-grade REST APIs using Django REST Framework, sustaining 90%+ test coverage across all repositories.
  • Introduced an event-driven architecture via AWS Lambda, decoupling core services and improving overall system resilience.
  • Collaborated cross-functionally to ship an MVP care management platform in six weeks, meeting a hard deadline to support a new line of business pilot.
PythonDjangoAWS LambdaECSCI/CD

HealthStream

Data Solutions Developer

Mar 2016 – Mar 2018 Nashville, TN
  • Designed and delivered a scalable data reporting platform on Amazon Redshift, supporting business intelligence needs across the organization.
  • Engineered ETL pipelines to migrate data from MSSQL to Redshift and tuned query performance against tables containing tens of millions of records.
  • Provisioned and maintained cloud and on-premises infrastructure using Terraform and Chef.
RedshiftETLPythonTerraformChef

Authentify

Software Engineer

Jan 2014 – Mar 2016 Chicago, IL / Nashville, TN
  • Developed multi-language SDKs and reference applications (mobile and web) to accelerate developer adoption of the company's out-of-band authentication platform.
  • Built an iOS application featuring biometric authentication — voice and fingerprint verification — using Objective-C.
  • Deployed and maintained RESTful services on AWS EC2 using Python/Flask and Java/Jersey frameworks.
PythonFlaskJavaObjective-CAWS

Gelber Group

Trader / Financial Engineer

Jul 2009 – Jan 2014 Chicago, IL
  • Researched, developed, and automated a futures pricing model that traded live across multiple products and exchanges — taking it from concept through to production deployment.
  • Built a suite of C# trading tools that ingested live market data and surfaced actionable signals for daily decision-making.
  • Developed MATLAB backtesting applications to rigorously evaluate and stress-test pricing models before going live.
C#MATLABQuantitative Finance

Earlier — Trading

Hard 8 Trading & Susquehanna International Group

2006 – 2009 Chicago, IL · CBOE

Traded equity options and managed live risk positions at two prominent Chicago-based firms, including one of the largest options pits on the Chicago Board Options Exchange. Developed early analytical tools in VBA and MATLAB and built foundational intuition for working under pressure in high-stakes environments.

Resume

Full Resume

View Full Resume

Bryan DeLeon

bdeleon@alum.mit.edu

Summary

Software engineer with an M.S. in Computer Science (University of Chicago) and a B.S. from MIT. 12+ years of experience building backend systems, cloud infrastructure, and data pipelines. AWS certified. Strong advocate for clean code, high test coverage, and reliable deployments. Background in quantitative finance brings an uncommon perspective on building systems that have to perform under pressure.

Technical Skills

Languages

Python, Java, C#, SQL, R, Objective-C, Swift, MATLAB, Ruby

Frameworks & Tools

Django, Flask, Docker, Kubernetes, AWS ECS / Lambda / Redshift / CodePipeline, Terraform, Chef, PySpark

Practices

REST APIs, Test-Driven Development, CI/CD, Agile / Scrum, OOP

Human Languages

English (native) · Spanish (working)

Experience

Sunday — Senior Back-end Engineer
Nov 2022 – Present · Boulder, CO / Remote
  • Owned a large-scale architectural refactor to decouple the core cart system, reducing technical debt and preserving critical business logic with minimal oversight.
  • Designed and built a store credit service integrated across purchase order confirmation, subscription reauthorization, and tax recalculation.
  • Diagnosed and resolved a series of critical issues in the flex pay installment system — including auth-fail recovery flows, subscription state remediation, and store credit application across multi-payment sequences.
  • Redesigned the Stripe integration for improved scalability, adding Apple Pay and Google Pay support.
  • Built proactive health monitoring alerts for out-of-stock inventory, overdue subscriptions, and cart anomalies — surfacing issues before they reached production.
  • Maintained and extended integrations with Avalara (tax), Klaviyo (email), Segment (analytics), UPS (shipping), and Amazon (soil test acquisition channel).
  • Managed recurring Django LTS upgrades, keeping the platform current with each new long-term support release.
Wayspring — Senior Software Engineer
Mar 2018 – Nov 2022 · Nashville, TN / Remote
  • Architected and maintained end-to-end CI/CD pipelines across development, staging, and production using AWS CodePipeline, CloudFormation, and ECS.
  • Designed and delivered multiple production-grade REST APIs using Django REST Framework, sustaining 90%+ test coverage across all repositories.
  • Introduced an event-driven architecture via AWS Lambda, decoupling core services and improving overall system resilience.
  • Built a proof-of-concept EHR integration delivering patient risk data into a provider's system on appointment creation.
  • Collaborated cross-functionally to ship an MVP care management platform in six weeks, meeting a hard deadline to support a new line of business pilot.
HealthStream — Data Solutions Developer
Mar 2016 – Mar 2018 · Nashville, TN
  • Designed and delivered a scalable data reporting platform on Amazon Redshift, supporting business intelligence needs across the organization.
  • Engineered ETL pipelines to migrate data from MSSQL to Redshift and tuned query performance against tables containing tens of millions of records.
  • Provisioned and maintained cloud and on-premises infrastructure using Terraform and Chef.
Authentify — Software Engineer
Jan 2014 – Mar 2016 · Chicago, IL / Nashville, TN
  • Developed multi-language SDKs and reference applications (mobile and web) to accelerate developer adoption of the company's out-of-band authentication platform.
  • Deployed and maintained RESTful services on AWS EC2 using Python/Flask and Java/Jersey frameworks.
  • Built an iOS application featuring biometric authentication — voice and fingerprint verification — using Objective-C.
Gelber Group — Trader / Financial Engineer
Jul 2009 – Jan 2014 · Chicago, IL
  • Researched, developed, and automated a futures pricing model that traded live across multiple products and exchanges — from concept through to production deployment.
  • Built a suite of C# trading tools that ingested live market data and surfaced actionable signals for daily decision-making.
  • Developed MATLAB backtesting applications to rigorously evaluate and stress-test pricing models before going live.
Hard 8 Trading — Trader
Jan 2008 – May 2009 · Chicago, IL
  • Traded and managed option positions; conducted daily analysis of portfolio performance and risk.
  • Developed MATLAB scripts to backtest and assess model viability.
Susquehanna International Group — Assistant Trader
Jul 2006 – Dec 2007 · Chicago, IL (CBOE)
  • Supported three veteran traders, including the head of the Chicago office, in one of the largest equity option pits on the CBOE.
  • Wrote VBA macros tracking live position data and automated Excel tasks for trading data.

Certifications

Python for Data Science edX · 2017
Scalable Machine Learning edX · 2015
The Analytics Edge edX · 2015
Statistical Learning Stanford University · 2014
Introduction to Linux edX · 2014

Education

Massachusetts Institute of Technology B.S. Management Science · Concentration: Finance · Minor: Economics
2002 – 2006 · Cambridge, MA
University of Chicago M.S. Computer Science
2013 – 2015 · Chicago, IL

Contact

Get in touch

I'm always open to interesting conversations — about engineering, systems, or just what's worth building next.

Email bdeleon@alum.mit.edu GitHub github.com/bdeleon LinkedIn linkedin.com/in/bdeleon