Apollo is the SMB-friendly sales intelligence and engagement platform — combines a contact database with engagement tools. Series D funding, fast-growing. The interview emphasizes data engineering at scale (hundreds of millions of contacts) and the unique challenges of running a B2B data platform.
Process
Recruiter screen → 60-minute coding phone (DSA medium) → onsite virtual: 2 coding, 1 system design, 1 craft deep-dive, 1 behavioral. Cycle: 3–4 weeks.
What they actually ask
- Design a contact database with hundreds of millions of records — expect to talk through sharding and partitioning (by company, region, or hash of contact ID), deduplicating the same person across sources, and indexing for fast name/company/title search. Interviewers push on how reads stay fast and how you keep duplicate or stale records out at that scale.
- Design data freshness and verification pipelines — how you re-crawl and re-verify emails, mark records stale, and choose batch vs streaming updates. Be ready to compare storage options (SQL vs NoSQL) and to explain email verification: catching bounces, syntax and MX checks, and a confidence score on each address.
- Design an email engagement engine with deliverability — sending infrastructure, per-domain rate limiting and IP warm-up, bounce and spam-complaint handling, and tracking opens, clicks, and replies. The deliverability angle — staying out of spam folders, honoring unsubscribes — is what separates a real answer from a generic queue design.
- Coding: medium DSA, often with data-pipeline framing — array, string, and hash-map problems, sometimes dressed up as deduping records, aggregating events, or merging feeds. State your time and space complexity as you go, since they care about how it holds up on large inputs.
- Behavioral: customer focus, ownership, fast-moving culture — prepare STAR stories about owning a feature end to end and shipping under time pressure. They probe for bias to action and for times you dug into a customer problem instead of waiting for direction.
Levels and comp (2026)
- SE II: $160K–$200K total
- Senior SE: $230K–$305K
- Staff: $320K–$430K
- Principal: $450K–$600K
Prep priorities
- Be fluent in TypeScript/Node.js (bulk of the codebase) — expect to read and extend real service code, not just whiteboard pseudocode, so know async/await, typing, and how you would structure a background job.
- Understand data engineering at scale and ETL patterns — batch vs streaming, idempotent reprocessing, backfills, and handling partial failures in a pipeline that touches hundreds of millions of rows.
- Brush up on email deliverability and CRM data — SPF/DKIM/DMARC, bounce and complaint rates, sender reputation, and how CRM objects (accounts, contacts, activities) map to a data model.
Frequently Asked Questions
Is Apollo remote-friendly?
Distributed-first since 2020. Hubs in San Francisco and remote across US. Most engineering roles fully remote.
How does Apollo compare to ZoomInfo or Salesloft?
ZoomInfo is enterprise-tier with deeper data. Salesloft is engagement-focused. Apollo combines both for SMB. Apollo pays competitively with similarly-staged startups.
What is the engineering culture?
Fast-moving, ship-focused, ownership-heavy. Younger team. Strong fit for engineers who like startup intensity.
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