About the role:
We are looking for a Senior Backend Engineer to build and operate the core AI/ML-backed systems that power large-scale, consumer-facing products. You will work on production-grade AI runtimes, retrieval systems, and ML-adjacent backend infrastructure, making pragmatic tradeoffs across quality, latency, reliability, and cost.
This role is not an entry point into AI/ML. You are expected to already have hands-on experience shipping ML-backed backend systems in production.
At Proximity, you won't just build APIs you'll own critical backend systems end-to-end, collaborate closely with Applied ML and Product teams, and help define the foundations that power intelligent experiences at scale.
Responsibilities
- :Own and deliver end-to-end backend systems for AI product runtime, including orchestration, request lifecycle management, state/session handling, and policy enforcement
- .Design and implement retrieval and memory primitives end-to-end document ingestion, chunking strategies, embeddings generation, indexing, vector/hybrid search, re-ranking, caching, freshness, and deletion semantics
- .Productionize ML workflows and interfaces, including feature and metadata services, online/offline parity, model integration contracts, and evaluation instrumentation
- .Drive performance, reliability, and cost optimization, owning P50/P95 latency, throughput, cache hit rates, token and inference costs, and infrastructure efficiency
- .Build observability by default, including structured logs, metrics, distributed tracing, guardrail signals, failure taxonomies, and reliable fallback paths
- .Collaborate closely with Applied ML teams on model routing, prompt and tool schemas, evaluation datasets, and release safety gates
- .Write clean, testable, and maintainable backend code, contributing to design reviews, code reviews, and operational best practices
- .Take systems from design build deploy operate, including on-call ownership and incident response
- .Continuously identify bottlenecks and failure modes in AI-backed systems and proactively improve system robustness
.
Requirement
- s:Bachelor's degree in Computer Science, Engineering, or a related field, or equivalent practical experienc
- e.610 years of experience building backend systems in production, with 23+ years working on ML/AI-backed products such as search, recommendations, ranking, RAG pipelines, or AI assistant
- s.Strong practical understanding of ML system fundamentals, including embeddings, vector similarity, reranking, retrieval quality, and evaluation metrics (precision/recall, nDCG, MRR
- ).Proven experience implementing or operating RAG pipelines, covering ingestion, chunking, indexing, query understanding, hybrid retrieval, and reranker
- s.Solid distributed systems fundamentals, including API design, idempotency, concurrency, retries, circuit breakers, rate limiting, and multi-tenant reliabilit
- y.Experience with common ML/AI platform components, such as feature stores, metadata systems, streaming or batch pipelines, offline evaluation jobs, and A/B measurement hook
- s.Strong proficiency in backend programming languages and frameworks (e.g., Go, Java, Python, or similar) and API developmen
- t.Ability to work independently, take ownership of complex systems, and collaborate effectively with cross-functional team
- s.Strong problem-solving, communication, and system-design skill
s.
Desired Skil
- ls:Experience with agentic runtimes, including tool-calling or function-calling patterns, structured outputs, and production guardrai
- ls.Hands-on exposure to vector and hybrid retrieval stacks such as FAISS, Milvus, Pinecone, or Elasticsear
- ch.Experience running systems on Kubernetes, with strong knowledge of observability stacks like OpenTelemetry, Prometheus, Grafana, and distributed traci
- ng.Familiarity with privacy, security, and data governance considerations for user and model da
ta.
About
us:We are Proximity a global team of coders, designers, product managers, geeks, and experts. We solve complex problems and build cutting-edge technology at sc
ale.Our team of Proxonauts is growing quickly, which means your impact on the company's success will be significant. You'll work with experienced leaders who have built and led multiple high-performing tech, product, and design te
ams.Here's a quick guide to getting to know us bet
- ter:Watch our CEO, Hardik Jagda, tell you all about Proxim
- ity.Read about Proximity's values and meet some of our Proxona
- uts.Explore our website, blog, and design wing Studio Proxim
- ity.Get behind the scenes with us on Instagram follow @ProxWrks and @H.Ja
gda.
