Front End Engineer

As a Frontend Engineer, you'll own the runtime that powers the modern internet. You'll design and maintain SDKs that process millions of events per day and emit billions of signals to enterprise level platforms enabling data collection that respects user choices while powering the modern ad-tech ecosystem. Every network request, every consent signal, every event flows through the infrastructure you build. If their ever goes down, major platforms you use daily may go down with it. The stakes are high.

This is infrastructure at an impossible scale, in the hardest runtime environment imaginable. You'll tackle performance, privacy, and reliability head-on, building systems that can't fail and architectures that ripple through Fortune 500 production environments. We operate with deep personal ownership which means that you'll solve problems from first principles, drive end-to-end solutions, and define the technical direction for client-side data governance at scale. You'll design SDKs used by thousands of engineers, integrating with the entire web and mobile stack, shaping the backbone of a free and fair internet.

Tech Stack

• Frontend : TypeScript, React, Rollup, ESBuild, Jest, Playwright
• Infrastructure : AWS (Lambda, CloudFront, S3), Docker, Terraform
• Integrations : Google Analytics, Meta, Snowflake, Datadog, FullStory, 100+ other platforms
• Observability & Telemetry : Datadog, Sentry, custom pipelines processing billions of events daily
• CI / CD & Delivery : GitHub Actions, automated pipelines, feature flags
• Mobile / Cross-Platform : iOS / Android SDKs, React Native (plus polyfills and platform-specific optimizations)
• Skills

React.js, Javascript, Typescript, Front end, sdk, React, Ui, mobile

• Top Skills Details

React.js, Javascript, Typescript, Front end, sdk

• Additional Skills & Qualifications

What You'll Own

• Design and evolve the core SDK runtime for consent orchestration, event tracking, rule evaluation, and platform integration at massive scale.
• Optimize SDK performance under impossible constraints and enforce deterministic client-side data governance across 50+ browsers / OS combinations, intercepting and managing network requests, cookies, and storage.
• Build APIs and tooling for thousands of engineers, making complex integrations simple, secure, and impossible to misuse.
• Extend SDKs for custom integrations, multi-platform routing, adtech connectivity, and AI-driven privacy telemetry.
• Simulate real-world network interactions with emulators and pipelines that feed AI models for privacy risk detection.
• Collaborate across product, design, and customer success, mentor engineers, and drive architectural excellence across the frontend team.

What We're Looking For

• Deep expertise in JavaScript & TypeScript (ES6+), browser APIs, event loops, closures, and high-performance client-side coding across diverse runtime environments.
• Proven experience building SDKs and JavaScript tags deployed on customer websites, integrating with internal and external platforms under production pressure.
• Mastery of browser architecture and client-side systems : rendering pipeline, network stack, storage APIs, cross-origin communication, and deterministic data flow governance.
• Performance and reliability wizardry : profiling, benchmarking, optimizing, and debugging async race conditions across distributed client-side systems.
• Systems thinking and build tooling experience : Webpack, Rollup, ESBuild, ESM / CommonJS / UMD, polyfills, and managing browser inconsistencies or third-party script conflicts.
• Collaboration, mentorship, and product-minded ownership : articulate technical decisions, influence stakeholders, drive pragmatic solutions, and elevate teams through code reviews and knowledge sharing.
• Bonus skills : mobile SDKs (iOS / Android / React Native), ad-tech
• Experience Level

Expert Level

• Job Type & Location
• This is a Permanent position based out of San Francisco, CA.
• Pay and Benefits
• The pay range for this position is $160000.00 - $200000.00 / yr.

Medica, dental, vision, life

• Workplace Type
• This is a hybrid position in San Francisco,CA.
• Application Deadline
• This position is anticipated to close on Dec 19, 2025.

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About TEKsystems :

We're partners in transformation. We help clients activate ideas and solutions to take advantage of a new world of opportunity. We are a team of 80,000 strong, working with over 6,000 clients, including 80% of the Fortune 500, across North America, Europe and Asia. As an industry leader in Full-Stack Technology Services, Talent Services, and real-world application, we work with progressive leaders to drive change. That's the power of true partnership. TEKsystems is an Allegis Group company.

The company is an equal opportunity employer and will consider all applications without regards to race, sex, age, color, religion, national origin, veteran status, disability, sexual orientation, gender identity, genetic information or any characteristic protected by law.

About TEKsystems and TEKsystems Global Services

We're a leading provider of business and technology services. We accelerate business transformation for our customers. Our expertise in strategy, design, execution and operations unlocks business value through a range of solutions. We're a team of 80,000 strong, working with over 6,000 customers, including 80% of the Fortune 500 across North America, Europe and Asia, who partner with us for our scale, full-stack capabilities and speed. We're strategic thinkers, hands-on collaborators, helping customers capitalize on change and master the momentum of technology. We're building tomorrow by delivering business outcomes and making positive impacts in our global communities. TEKsystems and TEKsystems Global Services are Allegis Group companies. Learn more at TEKsystems.com.

The company is an equal opportunity employer and will consider all applications without regard to race, sex, age, color, religion, national origin, veteran status, disability, sexual orientation, gender identity, genetic information or any characteristic protected by law.