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Ruben Rajkowski

Senior Full-Stack Engineer

Los Angeles, CA · Kalispell, MT

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Summary

Senior Full-Stack Engineer with 12+ years of experience architecting high-throughput, scalable web applications and production systems at NBCUniversal (Peacock). I set technical direction for platforms that serve ~9B monthly ad impressions across Peacock, NOW TV, and SkyShowtime and sustain 10,000+ TPS of live traffic at Olympics/NFL peaks—load-tested to 60,000 TPS during NFL Playoff games and the 2024 Paris Olympics. I use AI augmented engineering and agentic workflows to deliver resilient enterprise solutions across React, Node.js, Go, Python, and multi-model databases, and I drive cross-team architecture and engineering mentorship across a matrixed media enterprise.

How I work

For the past couple of years I've set architecture direction across teams, but the part of the job I enjoy most is building and solving problems. At Peacock I designed the Node.js ad-delivery config service, which handled 10,000+ TPS at p50 ~20ms and p95 under 1s at peak, against a 2s round-trip SLA, with 99.99% uptime, and I was on-call for incidents. I reviewed the code that shipped on it.

I'm looking for a role where I stay in architecture and the build — space for creative agency, not a job that's mostly reviews. I'm open to full-time or contract work if the fit is right.

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Experience

  1. Staff Software Engineer

    Feb 2024 – Present

    NBCUniversal, Inc. (Peacock) · Universal City, CA - Remote

    • Designed the Node.js ad-delivery config service (VAM): an OpenAPI contract and one data model shared by header bidding, experiments, VOD, live, and linear. 10,000+ TPS at p50 ~20ms, p95 <1s peak vs a 2s round-trip SLA, with 99.99% uptime, and I was on-call for incidents. Other teams build on it instead of forking config. Shipped a React UI on top, with Azure SSO.
    • Assisted with the Go rewrite of that service (ACE) and owned the A/B testing and Amazon APS header bidding modules: p50 ~10ms, p95 ~100–200ms typical. Also own two Go microservices on the same path: CDN steering, and asset-metadata ingest over Kafka.
    • Design knowledge systems and feature pipelines that ground model output in production data for targeting, analytics, and internal tooling. The product question is cost, relevance, and whether the answer matches the source.
    • Ship with Cursor (IDE and agents). I still own the contract, the failure mode, and the merge.
    • Production on Kubernetes (EKS) in AWS: scaling, multi-region, monitoring. Set direction across a matrixed org without a team under me.

  2. Senior Software Engineer

    Jun 2020 – Feb 2024

    NBCUniversal, Inc. (Peacock) · Universal City, CA - Remote

    • Owned Video Ad Manager v1 for the Peacock launch. Node.js services in front of the live and VOD ad path, split into microservices so a bad deploy did not take the whole break with it.
    • Held the on-call path for NFL Playoffs and the Olympics. High-traffic nights meant no-fill spikes and latency in the middle of a game, traced in production and fixed before the next break.
    • Those sessions ran late. The work was the live event, not a ticket queue. The same platform now serves ~9B ad impressions a month across Peacock, NOW TV, and SkyShowtime, with 10k+ TPS of live traffic at Olympics and NFL peaks.
    • Left the v1 contracts in a shape the Go rewrite could take over: one config model, explicit APIs, and services other teams were already calling.

  3. Senior Software Engineer

    May 2017 – Jun 2020

    NBCUniversal, Inc. · Universal City, CA - Hybrid

    • NBCUniversal ad platform, before Peacock. Owned solution architecture for Ad Manager v1 on AWS. Serverless services and DynamoDB behind real-time bidding across FreeWheel, Amazon header bidding, and Roku. Splunk for no-fill and latency. Prometheus and Splunk alerts. OpenAPI standards and SAML/OAuth plugins other teams adopted.

  4. Senior Frontend Developer

    Feb 2014 – May 2017

    NBCUniversal, Inc. · Universal City, CA - On-site

    • Built display-ad delivery on Google Ad Manager and Google's ad APIs for high-traffic NBCU properties including NBCNews.com and Fandango.com. Owned campaign setup and delivery screens in the internal ad CMS (PHP, JavaScript, SQL), plus the SAML and OAuth path into the tool.
    • Built the JavaScript client authentication for NBCUniversal MediaVillage (nbcumv.com), NBCU's media-sharing platform, still in use today.

  5. Sr. Front End Engineer

    Jul 2011 – Jan 2014

    Dex Media, Inc. · Santa Monica, CA - On-Site

    • Owned JavaScript sales applications for consumer platforms reaching 15 million monthly users. Shipped with Product and QA, from scope through release.

  6. Co-Founder & Software Engineer

    Jan 2009 – Feb 2011

    Breaking Development · Self-employed · Greater Los Angeles Area - On-site

    • Co-founded a consultancy. Scoped and shipped custom web applications with no engineering org behind the work.

  7. Web Developer

    Mar 2008 – Mar 2010

    Jakks Pacific · Contract · Malibu, CA - On-site

    • Built the consumer site for a toy company. Owned the product pages and kept them up through campaign launches.

Technical capabilities

Frontend

TypeScript React GraphQL

Backend

Node.js Go Python REST OpenAPI Kafka MongoDB SQL

Auth

OAuth SAML Azure SSO

Platform

Docker Kubernetes AWS CI/CD Prometheus Splunk

AI

Cursor Copilot RAG LLM APIs

How you work

System design Microservices Mentorship

Media

Live streaming Header bidding Ad A/B testing

Education

Bachelor of Science in Computer Science

The Master's University