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(USA) Senior, Software Engineer

Walmart

Bentonville, AR
Full Time
Senior
90k-180k
about 1 month ago

Job Description

About the Role

We are hiring a Senior Software Engineer to pioneer the development of a custom cache / vector database engine powering Walmart's next generation Connected TV (CTV) Ads platform. This role is critical to build and scale ad infrastructure to serve 10M+ smart devices in real time. You'll design and implement high-performance, memory-efficient components that sit at the intersection of real-time vector search, LLM query pipelines, and privacy-aware audience targeting. You will develop performant code in Rust, C, or Go, optimizing for latency, memory footprint, and scalability. Walmart's Advertising Technology group enables the connection between supplier brands and retail shoppers at unprecedented scale, serving billions of ad requests monthly with high-performance ad servers. The team includes engineers and data scientists working on sophisticated, high-impact problems to optimize advertising campaigns and deliver relevant content to millions of customers daily.

Key Responsibilities

  • Design and build a custom in-memory + on-disk vector database engine optimized for sub-millisecond latency at scale.
  • Architect a native caching solution from scratch to support concurrent lookups and evictions with strong consistency guarantees.
  • Handle concurrent LLM queries via efficient scheduling or batching techniques with the vector DB of choice.
  • Partner with ML engineers to ingest, index, and retrieve vector embeddings from multimodal signals (audio, frame-level video).
  • Profile and fine-tune for low memory usage, disk I/O throughput, and multi-core CPU parallelism.
  • Collaborate with product, infra, and ad delivery teams to integrate with data pipelines, contextual matching, and real-time bidding systems.
  • Build and iterate on POCs quickly to test, validate and scale new architectural ideas.

Requirements

  • 6+ years of hands-on backend/systems experience with Rust, C/C++, Go Lang or Python.
  • Proven track record of building or contributing to databases, key-value stores, caching systems, or search engines.
  • Strong understanding of memory models, lock-free/concurrent data structures, and efficient serialization (e.g., protobuf, flatbuffers).
  • Experience integrating vector DBs (e.g., FAISS, Milvus, Vespa, Pinecone) or building custom ANN libraries.
  • Experience optimizing workloads on resource-constrained devices, with attention to latency.
  • Deep knowledge of vector similarity search, ANN techniques, and index compression.
  • Comfortable operating in high-throughput, low-latency ad-serving environments.

Nice to Have

  • Contributions to open-source projects or patents in vector indexing, caching, or embedded DBs.
  • Understanding of real-time ML inference, ML Ops, or LLM-enhanced retrieval in production.
  • Familiarity with CTV ad pipelines, SSAI, frame fingerprinting, or video scene detection.

Qualifications

  • Option 1: Bachelor's degree in computer science, computer engineering, computer information systems, software engineering, or related area and 4 years' experience in software engineering or related area.
  • Option 2: 6 years' experience in software engineering or related area.
  • Preferred: Master's degree in relevant field and 2 years' experience in software engineering or related area.

Benefits & Perks

  • Incentive awards for performance.
  • 401(k) match, stock purchase plan.
  • Paid maternity and parental leave, PTO, multiple health plans.
  • Health benefits including medical, vision, and dental coverage.
  • Paid time off including sick leave, parental leave, family care leave, bereavement, jury duty, voting.
  • Short-term and long-term disability, company discounts, Military Leave Pay, adoption and surrogacy expense reimbursement.
  • Live Better U education benefit program covering tuition, books, and fees.

Working at Walmart

Imagine working in an environment where one line of code can make life easier for hundreds of millions of people. Walmart Global Tech is a team of software engineers, data scientists, cybersecurity experts, and service professionals within the world's leading retailer who make an epic impact and are at the forefront of the next retail disruption. They are people-led and tech-empowered, focusing on innovation, growth, and creating accessible digital experiences that support an inclusive culture.

Apply Now

Job Details

Posted AtJun 16, 2025
Salary90k-180k
Job TypeFull Time
Work ModeHybrid
ExperienceSenior

Job Skills

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About Walmart

Website

walmart.com

Company Size

10000+ employees

Location

Bentonville, AR

Industry

Warehouse Clubs, Supercenters, and Other General Merchandise Retailers

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