Senior Backend Engineer

Mosaic.tech; New York (NY); On-site; USD 140,000 - 210,000; Full time

Job summary

Mosaic.tech in New York is building a scalable data platform to power product analytics and AI-driven insights. We seek an experienced Data Engineer to own core data systems, optimize PostgreSQL workloads, and design fast analytical schemas.

You will work with AI-native analytics, lead data architecture decisions, and collaborate with engineers to ensure reliability, observability, and long-term maintainability.

Qualifications

• Minimum 5 years of relevant experience.
• Proficient with PostgreSQL in production.
• Experience designing analytical data architectures.
• Ability to lead ambiguous, high-impact work.
• Ownership mindset with logs and metrics focus.

Responsibilities

• Own core data systems powering Mosaic.tech.
• Stabilize and harden high-throughput write paths.
• Design data access patterns for fast analytics.
• Separate transactional and analytical workloads; decide workloads/placement.
• Build read-optimized models and schemas for analytics.
• Enable AI-native analytics and queries over data.
• Make architectural decisions and RFCs to guide the platform.
• Improve reliability and performance across the team.

Skills

PostgreSQL

System design

Observability

Analytical schemas

Performance tuning

Data pipelines

Ownership mindset

High ownership

Job description

Why Plot

Plot is building the next generation of social intelligence – an AI‑native platform that helps some of the world's most influential brands understand culture, find emerging trends, and activate their communities at scale. We're a high‑growth, venture‑backed startup supported by the co‑founders of Reddit and Plaid, with customers like Tory Burch, Lululemon, La Roche‑Posay, and other household names. We operate at the intersection of applied AI and large‑scale data systems, turning millions of short‑form videos every day into structured representations of culture and consumer behavior. Plot makes unstructured social media legible at scale, enabling brands to build a deep, systematic understanding of trends, audiences, and influence. You'll join a small but mighty team where engineers own systems end‑to‑end — not tickets. You'll work directly with founders, shape foundational architecture, and make decisions that define how Plot scales for years to come. If you enjoy ambiguous problems, deep systems thinking, and building infrastructure that unlocks entire product surfaces, Plot is the place. It’s also a great fit if you aspire to be a technical founder one day – we operate with a strong founder’s mindset.

What You’ll Work On

• Own the core data systems that power Plot. You’ll take responsibility for how millions of enriched videos flow from ingestion → storage → analytics → product surfaces.
• Stabilize and harden high‑throughput write paths. Our pipelines ingest and enrich data continuously; you’ll diagnose failure modes, reduce error rates, and make ingestion reliable, observable, and predictable.
• Design data access patterns that stay fast under pressure. You’ll ensure dashboards and analytical queries remain responsive even while large volumes of data are being written concurrently.
• Separate transactional and analytical concerns. You’ll lead decisions around which workloads belong where, and design the systems and contracts that keep them from stepping on each other.
• Build read‑optimized models for insight, not just storage. This includes partitioning strategies, rollups, and schemas that reflect how data is actually queried — by humans and by AI.
• Enable AI‑native analytics. You’ll shape how our internal tools and AI agents query and reason over data, making it possible to answer complex analytical questions without brute‑force scans.
• Make architectural calls that matter. You’ll evaluate tradeoffs, write RFCs, and guide the evolution of Plot’s data platform as scale, product needs, and AI capabilities grow.
• Raise the bar for reliability and performance across the team. You’ll define best practices, unblock other engineers, and become a go‑to resource for data‑related decisions.

What We’re Looking For

• Deep experience operating Postgres in production under real‑world read/write concurrency. You understand partitioning, locking, autovacuum, connection pooling, and why systems fail in subtle ways.
• Strong systems intuition. You think in bottlenecks, failure modes, and tradeoffs — not just indexes or tooling.
• Experience designing or owning analytical data architectures, including read‑optimized schemas, aggregations, or large‑scale querying patterns.
• Comfort leading ambiguous, high‑impact work. You can take a messy system, form a clear mental model, and chart a pragmatic path forward.
• High ownership mindset. You like digging into logs, metrics, and real data — and you care deeply about correctness, reliability, and long‑term maintainability.
• Curiosity, pragmatism, and a desire to build foundational systems that other engineers and AI systems depend on. No degree requirements.
• Minimum 5 years of relevant experience.